The tinkerers and weight weenies that scour the internet for the latest tech to shave off a few grams or conserve a couple of watts know that there is no shortage of upgrades that can bring marginal gains to their ride.

Weight-saving upgrades come at a price, and that price increases exponentially as cyclists refine their equipment to make their bikes as fast, light, and efficient as possible. Saving just a couple of grams can cost hundreds and hundreds of dollars – have you looked at any Titanium, high-end carbon, or electronic components lately? They’re not exactly cheap.

In this economy, more riders may find themselves pinching pennies while still hoping to find an affordable upgrade that will take their riding to the next level.

According to Hayes Bicycle Components, dollar for dollar, that upgrade is brakes.

Why should you upgrade brakes?

Sure, a shiny-new electronic drivetrain will make a bike more efficient and carbon wheels will change the feel of the road or trail considerably, but new brakes can make riders feel incredibly well connected to a bike and confident to push themselves to the next level.

It’s difficult to ride confidently if you don’t trust your stopping power. Sadly, many brakes that come on new bikes, especially on the entry-level side of things, tend to be a little underpowered. Now, that doesn’t mean they don’t work, but they’re often not as responsive as some of the other options out there.

Brakes are an upgrade that all levels of riders can appreciate. While certain creature comforts and technologies may be more valued by high-level riders, reliable and powerful brakes provide real benefits to riders of all levels – from the newer untrained riders all the way up to World Cup champions. Poorly functioning brakes aren’t just a safety risk; they can also be a huge nuisance. Constant bleeding, unreliable performance, and low power are a few pitfalls that can completely ruin the riding experience for the novice and the pro alike. Better brakes can completely change the experience in the saddle.

Instead of racking up a few thousand dollars in carbon or electronic upgrades, most brake systems will only set a rider back a few hundred bucks, so if you’re looking for the best dollar-for-dollar upgrade to your ride, look no further.

What makes a good brake system?

Stopping power is the most important aspect of brakes, and there’s a lot that goes into it. Since most riders weigh between 100 – 250 pounds, there is a tremendous amount of force required to slow that momentum down.

Hayes Bicycle Components has been manufacturing high-end brake systems since the late 1990s, slowly refining its designs over more than two decades to create a product that does exactly what it is supposed to do: stop.

Hayes’ latest range of the Dominion family of brakes, including the A4, T4, T2, and A2, provides a great snapshot of the impact new brakes can have on a ride. The Dominion A4, which has long been a staple of the brand, uses a motorsports-inspired two-stroke dual-port bleed system, along with a hydraulic system that works consistently in a wide variety of temperatures and conditions. Whether you’re in the heat of the desert or the cold of the mountains, your brakes will function as expected.

The T4 and T2 models include titanium hardware and carbon-fiber levers to keep weight at a bare minimum. The A2, the newest offering in the lineup, also includes a compact two-piston caliper designed for XC and trail riders.

The Dominion line features a master cylinder that is fine-tuned to eliminate the dead space riders can feel from when they first squeeze the brake lever to when the brake pads actually clamp down on the caliper. This means riders will feel an immediate response, a powerful bite without hesitation, and modulation all through the way through the stroke.

Fit and feel

While the stopping power is the most critical element of any brake system, it’s important to remember that brakes are also a vital contact and interface point on the bike. The ergonomic qualities and handlebar position of brake levers and how a rider engages them can lead to fatigue, pain, or even injury. They also can prevent it.

For brakes with less power, riders often have to use multiple fingers, or all of them, to squeeze as hard as they can to come to a stop. This is especially true on downhill courses. The Hayes Dominion line comes with an ergonomic finger lever that doesn’t require extreme levels of force. It also comes with an optional Short Reach Lever that brings the lever closer to the bar for easy single-finger braking for riders with smaller hands. Its design also enables riders to adjust the reach of the lever with no tools for quick, no-hassle tuning even while on the trail.

Considering the amount of time folks spend interacting with their brake levers, they really need to be well-designed to ensure they remain comfortable and easy to use, even during long rides.

Style

Aside from the aforementioned performance improvements a new set of brakes can bring to a bike, they also can bring a touch of flare that can take a bike from something that looks like it came off of a shelf to a custom build. The Dominion A4 brake comes in a handful of colors including Bronze, Stealth Black / Grey, and an eye-popping limited edition Purple Hayes.

Hayes Brakes are a component that checks all of the boxes of performance, fit, and style all in one package.

The Hayes Dominion line sells for an MSRP ranging from $250 to $350, making it one of the places to look for riders aiming to get the most bang for their buck when upgrading their ride. Even after adding new rotors, a complete set could still come in well under $1,000 and completely revamp the feeling of any bike.

The post AASQ: What is the Best Bike Upgrade for the Least Amount of Money? appeared first on Bikerumor.

Over the 21 stages of the Tour de France, riders of the Pro Peloton may ride a number of different models from their frame sponsor. They will switch between the brand’s dedicated aero road bike, time-trial bike, and lightweight climbing bike, making a decision based on what that stage will bring on the day; elevation profile, wind conditions, mileage, terrain, etc., all need to be carefully considered to ensure the rider is optimally equipped. The team looks to control any factor that is controllable.

We recently received a thought-provoking question from a reader on this very topic, a question that was the inspiration for this feature. Not being aerodynamics specialists or engineers ourselves, we have recruited expertise from some of the top road frame manufacturers whose bikes can be seen throughout any Pro Peloton. Specialized, Trek, Cervélo, and Cannondale all bring some interesting and insightful discussion on the topic, ranging from the succinct and easily digestible to the results of some rather revealing virtual simulations.

The Reader’s Question

“The gradient at which it is said that weight begins to trump aero is typically around 8% for pro riders. Obviously, the slower one can ride and climb must affect this transition point in gradient. How does this gradient transition reduce as the available power output reduces for those of us who are not pros?”

The answer to that question is, it depends, as we will soon find out from our team of experts. The discussions offer some insight into bike choice in the Pro Peloton but also deliver some golden nuggets of advice as to what kind of bike we amateur cyclists would go best on.

Our contributors are:

• Marcel Keyser, an engineer with the Specialized Human Performance Team
• The Cervélo Engineering Department
• Trek Senior Aerodynamicist, John Davis
• Dr. Nathan Barry, Cannondale engineer and aerodynamicist

Dr. Nathan Barry, Cannondale Engineer, and Aerodynamicist

The simple answer is that the less power to weight a rider has, the slower they climb, and the lower the gradient of the tipping point between aerodynamic and weight savings. But that only scratches the surface of this phenomenon. To fully address this question, it’s important to go back to the fundamental science that underpins this concept to make sure there are no misconceptions. The statement of one specific gradient where weight trumps aerodynamics is an oversimplification from some arbitrary specific set of parameters.

The underlying mechanics of cycling, described by the cycling power equation, show that aerodynamics is a function of velocity, with no dependence on gradient or mass. Conversely, climbing power is a strong function of mass, gradient, and velocity. Taking the extreme edge cases; on a flat road (0% gradient) a rider expends 0 W of climbing power. At a constant speed, mass has a minimal impact on the power required, thus most of a rider’s power is spent overcoming aerodynamic drag. As the road gets steeper, the rider must expend climbing power, leaving less power to overcome drag, therefore their speed drops. So at some very steep gradients, a rider will have very low velocity such that aerodynamic resistance becomes minimal and the majority of the rider’s power is spent overcoming the gradient.

It stands to reason then, there will be some cross-over point along this gradient spectrum at which the rider expends an equal amount of power overcoming both drag and climbing power. However, this still isn’t the full picture. The question of interest isn’t about the magnitude of power, but rather differences in performance. What we are really interested in is how changes in drag or mass affect performance. A simple example might be a choice of wheels. A shallow wheelset might be lighter but sacrifices aerodynamic efficiency compared to a well-engineered deeper rim. Clearly, on a flat road the deeper, low-drag wheelset is preferable. The question becomes, how steep does the road need to be before the lightweight wheels are faster than the heavier but lower-drag wheels? Often this is referred to as the tipping point.

What becomes clear from this example is that the gradient at which the tipping point occurs will depend on the relative difference in drag and mass. A big drag savings with a small weight penalty will have a much higher tipping point than a change that has a small drag savings but large weight savings. The tipping point is also a function of velocity. Even when climbing, a rider is pushing through the air so there is always a component of aerodynamic drag. While it is reduced at lower speeds while climbing, it never drops to zero, so long as you are moving. As noted in the question statement, this is the reason why the tipping point is higher for professionals. Due to their higher power (and power to weight), they climb faster, and at a given gradient, they are traveling faster than an amateur and so have higher aerodynamic resistance to overcome. Aerodynamic savings have a larger influence on performance.

A second concept to layer on top of this is that these differences in rider performance are related to the system as a whole, not just the component, or the bike. Consider a wheelset upgrade that saves 100 g of weight — ignoring any aerodynamic differences for now. For a high-performance wheelset in the range of 1,600 g, a 100g reduction is a big saving (6.3%). For a complete bike of ~7.5 kg that would be a 1.3% weight reduction. However, cycling performance is determined by the total system mass — including the rider.

Typically, the bike is only about 10% of the total system weight. For a 75kg rider on this bike, the 100g weight savings is only a 0.1% reduction in system mass. As such, the climbing performance improvement from such a change will be proportionally small. The same is true of differences in aerodynamic drag. Changes in drag need to be considered as a function of the whole system. However, a 10% reduction in system mass is impossible when considering only the bike, this is not out of the realm of possibility when you consider a bike with no aerodynamic optimisation versus one dedicated to lowering drag.

How does rider power affect the gradient transition? There is no one answer to this; it comes down to those three key variables: change in drag, change in mass, and rider power to weight. For a given configuration (a given difference in drag and mass) you can model a curve for tipping point versus rider power to weight. This will show how your performance with a given setup compares to that of a pro who might have significantly higher power to weight. But that will only apply to that specific equipment configuration. As soon as you change the relative differences in drag and mass, the model will no longer be relevant. It is hard to simplify this since differences can vary widely. Between wheelsets, frames, cockpits, helmets, and clothing, there can be big differences in both drag and mass.

To try and provide some insight to those who don’t want to build all this into a spreadsheet, we can frame some of these principles in a less complex way using a very simple case study. Consider what happens when you add 1 kg of dead mass to your bike, i.e. with no benefit from reduced drag. In the context of high-performance road bikes, this is a big change in bike weight. Certainly, something that a rider will feel when they hold or pick up the bike. Most road riders would consider this to have a dramatic impact on performance. If we take a case study for an amateur rider: a 75kg rider, 7.5kg bike, 7% gradient climb, 15km/h road speed. Climbing at this speed and slope would require ~275 W. An amount sustainable for a fit amateur rider of this size (3.7 W/kg). The addition of the 1kg dead weight would add only 3W resistance under these conditions. This is not nothing, but it is just a little over a 1% increase in resistance. For a rider who isn’t competing at a high level, this difference is not going to make or break their ride. In fact, this equates to less than 0.5-second time loss over a 5km climb. If we reduce that performance to 2.5 W/kg the power difference is 2 W and the time difference is 0.5 seconds to the same significant figures. Basically, less power available reduces road speeds, which reduces the magnitude of power differential but increases the time saved — since the rider’s total time over the segment is proportionally longer.

Weight is not as significant as most riders probably believe. Even with no aerodynamic improvement, a 1 kg difference has a relatively small impact on road speed. Conversely, if you start with a setup that has relatively high drag, a 1kg mass difference could be spent on a huge amount of aerodynamic optimisation. For the same rider and power output you could see at least 20W power savings on a flat road when comparing a classic round tube frame with low-profile wheels to a modern race bike. So perhaps a simpler question to address this phenomenon is how much should a rider care about weight or aerodynamics? While it is much easier to feel and measure the weight of a bike, for almost all riders and scenarios, aerodynamic optimisation will have a much greater impact on your on-road speed than reducing the weight of the bike.

If we revisit the wheel comparison from earlier, we can consider one specific equipment choice and examine the calculation of the tipping point for our 75kg rider at 275 W. Take two wheelsets: the first is lightweight at 1,300 g but has a shallow rim and high drag. The second uses a deep aerodynamic rim with a weight of 1,500 g and a drag reduction of 0.010 m². This represents a realistic figure based on wind tunnel test results for a pair of wheels on a complete bike.

The power distribution as a function of gradient for this rider is plotted below. This model effectively has the rider maintaining a constant power output and redistributes that power based on the requirements at each gradient. From experience, we know that the increase in gradient is coupled with a decrease in speed. At 0% the rider is moving very quickly (~38 km/h), compared to very slowly (~11 km/h) at 10%. This plot highlights how the rider’s power distribution changes as the road becomes steeper. With increasing gradient, there is more power required to overcome the elevation gain, leaving less power available to maintain the speed seen on the flat. As speed drops, so does the aerodynamic power requirement.

For the two wheels, we can calculate these power distributions for each configuration. Comparing the two sets we can derive the tipping point to occur at a gradient of 6%. Remember that this is the inflection point. At any gradient up to 6%, the heavier, lower-drag wheelset is faster. Only once the gradient exceeds 6% is there any advantage for the lighter wheelset. Note, in the above graph, that at a gradient of 6% significantly more of the rider’s power is distributed to climbing compared to air resistance, and yet the performance of the two configurations is equal at this gradient. This comes down to the relative impact of those differences on the performance balance. As described earlier, changing rider power, drag savings, or weight savings will change the value of the tipping point.

The figure above shows the power difference based on a fixed velocity (as calculated for the first configuration with the heavier, lower drag setup). In this case, positive values indicate the additional power required by the lighter wheelset, negative values indicate where the lighter wheelset is saving power over the heavier wheelset. The horizontal intercept at 6% indicates the tipping point. Note that the magnitude of power difference between the two configurations is not equivalent. Whilst the lighter wheelset is faster above 6% the power saved is an order of magnitude smaller than the savings seen with the low drag wheelset on low gradients.

Cervélo Engineering Department

Aerodynamic impact grows non-linearly as speed increases. Pro riders produce more watts and weigh less, which results in a faster average speed — which also means the absolute aerodynamic impact is greater.

Relatively speaking, on flat ground, an amateur rider will benefit more from an aerodynamic frame than the pro rider because they produce less power and typically weigh more, and the aerodynamic reduction in drag is a greater percentage of their total power output.

Once the road goes uphill, though, weight becomes the determining factor, and speeds drop. A pro rider will still produce more power and weigh less than an amateur rider, so they will maintain a higher speed, which maintains aerodynamic performance. An amateur rider will weigh more and produce less power, so their speed will drop more quickly than a pro, also reducing the aerodynamic impact of the bike.

Assuming bike weights are the same, along with the assumptions stated above regarding power output and rider weight, the weight versus aero tipping point for the average rider is likely around a 4-5% gradient versus approximately 8% for the pro rider.

John Davis, Trek Senior Aerodynamicist

The reader’s 8% tipping point was accurate several years ago for the trade-off between typical aero and lightweight bikes at pro speeds. However, with most race bikes receiving aero treatment nowadays, that tipping point has been reduced.

Keep in mind that on a loop course, you must descend what you climb. Factoring in descending, the Emonda versus Madone tipping point for an out-and-back climb and descent changes from ~3% to ~6% for the 150W rider (this simplistic calculation neglects braking losses).

Now, almost all race bikes receive some aerodynamic treatment, which has reduced the tipping point from the ~8% level the reader asked about. This example compares our 2018 Emonda versus our 2021 Emonda, but the same trend is often seen across the industry.

Other factors that come into play:

• I assumed no wind; headwinds and most crosswinds will push the tipping point in favor of the aero bike while tailwinds will push the tipping point in favor of the climbing bike
• Increasing rider weight will push the tipping point in favor of the climbing bike and decreasing weight will push the tipping point in favor of the aero bike (roughly by 0.2% grade for every 10 kg in this example)

Marcel Keyser, Engineer With the Specialized Human Performance Team

For the simulation, we created three “virtual” bikes — weight, CdA (coefficient of aerodynamic drag), and a consistent rolling resistance — and ran them in a number of scenarios. We used our Tarmac SL7, the Aethos, and then a “pure” aero bike based on what we know from many dedicated aero road platforms from a variety of manufacturers. 

The rider has 70 kg + 1 kg of gear. Rolling resistance is similar to a nice Turbo tire.

Conclusions

A. General

1. The stronger a rider is, the steeper the road needs to be to hit the break-even between aero and weight. 
2. Stronger riders work more against aero due to higher average speeds.

B. Tarmac SL7 vs. Aethos (Lightweight)

1. Climbs need to be steeper than approximately 5% to see the advantage of the lower weight.
2. It’s interesting to see how different rider speeds play a big role in when the Aethos versus the Tarmac choice delivers an advantage.

Based on 3 W/kg, 4.5 W/kg, and 6 W/kg, representing amateur, strong amateur, and pro riders, respectively — we know it starts to matter beyond 5% grade for all riders, but the big-time gaps don’t occur until steeper slopes, so we calculated the time delta (change) over an hour of riding a 10% slope on a Tarmac versus an Aethos for each of these riders. Essentially, how much faster the Aethos covers the distance that a Tarmac SL7 does in an hour. You’ll see that, and watts saved, in the below summary graphs.

• At 3 W/kg, the Aethos is 25 seconds ahead after an hour over the Tarmac SL7 on a 10% slope. 
• At 4.5 W/kg, the Aethos is 19 seconds ahead after an hour over the Tarmac SL7 on a 10% slope.  
• At 6 W/kg the Aethos is 14 seconds ahead after an hour over the Tarmac SL7 on a 10% slope.  

It’s important to note that with today’s races, the aero advantage over an entire day and the rarity of any race with sustained 10% slopes, combined with the need to add ballast to make an Aethos UCI legal, make the Tarmac SL7 the undeniable race choice for our riders.

We did the Tarmac SL7 versus a “Classic” aero road bike for fun too. The results were pretty incredible. The Tarmac SL7 gives up almost nothing on the flats and gains 4X that time back on a climb.

C. Tarmac vs. “Classic” Aero Bike

1. There is almost no disadvantage on FLAT road.
2. The delta power plot shows approx. 1 W disadvantage on flat and 2 W advantage on climbs for the Tarmac. This sounds like 50%/100%.
3. BUT! Look at the TIME savings per hour bar graphs in the summary plots above:

• The Tarmac loses 5 seconds in 1 hour on the FLAT and wins 20-25 seconds in 1 hour on a CLIMB versus the “Classic” Aero Bike.
• This delta is huge, validating the incredible combination of lightweight and aero that the Tarmac delivers.

Thank you again to Specialized Bicycles, Trek Bikes, Cervélo, and Cannondale for contributing to this feature.

The post Aerodynamics vs. Weight: What’s the Tipping Point for Pro and Amateur Cyclists? appeared first on Bikerumor.

Rear shocks come in a wide variety of shapes and sizes that manufacturers tailor to very specific needs of riders ranging from XC racers to downhill shredders.

For many, swapping out a shock is an expensive and anxiety-inducing task that involves a bit of math, and a whole lot of research to find the right rear-end trail partner.

That question is not necessarily a simple one. Local trails are littered with strong riders sporting both options. In most cases, they will all tell you their setup is superior.

In the end, the debate over air or coil shocks comes down to fit, feel and ride style.

What are the benefits of an air shock?

Air shocks are pretty much the only thing you’ll see on lower-travel mountain bikes. As a rule, they are lighter than their coil counterparts and more progressive in their travel.

That means that as the shock compresses, it takes more force to move through travel, reducing the frequency with which they bottom out.

However, because of the internal pressurized components of air shocks, there usually are more friction points that can cause minor kinks as the shock progresses through its full travel.

Additionally, oil inside air shocks tends to heat up during rides, particularly those in which the shock sees a lot of motion. Extended technical downhill sections or rock gardens create friction inside the shock that heats oil and air inside. Less viscous oil means a shock will move a bit more freely, so it may not feel as dialed as when the ride began.

Shocks like the Fox Float X and Float X2 are among many that ease this issue with a piggyback system. But shocks with piggybacks generally only go on longer-travel bikes, not on lower-travel XC rigs.

What applications or ride types are better suited to air?

Air shocks are ideal for cross-country riders and anyone who is looking to save weight. Coil shocks tend to be heavier than air shocks, so running them is pretty much a no-go for many racers. However, air shocks don’t solely cater to XC race types.

Even seasoned downhillers use air shocks. One of the biggest benefits of air shocks is their adjustability. Bikes are so versatile now that many are right at home at the downhill park and still fun to cruise flat singletrack or hike-and-bike trails.

Being able to dial in the suspension to account for that much variability in trail conditions is incredibly important in a do-it-all bike.

What are the benefits of a coil shock?

What coil shocks lack in at-home adjustability, they make up for in their smoothness and responsiveness. Most people use the word “supple” to refer to coil shocks.

Unlike the progressive nature of air shocks, coil shocks usually have a linear travel profile, meaning the same amount of force is required to move the shock through particular points deeper in the travel. That provides consistency and uniform responses to rider input.

Keep in mind, not all bikes can accommodate a coil shock. To get the best benefit from a coil shock, riders should select a bike that is designed to accept that type of suspension and compensate for the linear profile.

While not as easy to adjust, coil shocks still have some tunability. It’s just a bit more complicated to dial in.

To significantly change the pressure of a coil shock, riders usually have to buy a new coil. It’s not necessarily cheap and can involve some trial and error before finding the perfect spring.

Since coil shocks are built around an exterior spring, they do not usually see the same issues with friction and heated oil as air shocks.

What applications or ride types are better suited to Coil?

For the most part, coil springs thrive in the downhill arena. Their responsiveness helps riders feel more connected to the bike and stuck to the ground. Enduro riders, too, often run coil shocks. Since the speed of climbs doesn’t really matter, many are happy to find a shock that is smooth and supple when headed downhill, as long as it isn’t a complete slog when the trail points upward.

With the right coil shock, climbing should still feel relatively efficient. Coil shocks come with a bit of a weight penalty. But even for everyday trail riding, those who are not concerned with a little extra weight can often find a more consistent cushioned feel with a coil.

Which is more tunable for the at-home mechanic?

Air shocks easily win the at-home tuneability category, especially for bikes on the lower end of the travel spectrum. They provide more versatility that can help riders dial in feel for different trail or weather conditions and account for added weight.

With a shock pump, riders can dial in resistance based on their body weight, and quickly make changes to account for the added weight of things like large water bladders or bike-packing luggage. Air volume (not pressure) is also fairly easy to tune with the use of volume spacers. These spacers go inside the air chamber of the shock, and change the amount of mid-stroke and bottom-out resistance.

They also utilize rebound controls and lockout switches that typically include two or three stages for full-open, mid-open, and locked-out positions to make climbing or tame trail riding more efficient.

For example, the Fox Float X2 includes eight different click settings for high-speed compression, 16 for low-speed compression, eight for high-speed rebound, and 16 for low-speed rebound. That’s a lot of wiggle room.

However, Fox’s DHX and DHX2 are not without tuneability. Both come with an option two-position open/firm lever to tighten things up in climbs. The DHX offers an adjustment range of 16 clicks for low-speed rebound and 11 for low-speed compression. The DHX2 offers eight clicks for high-speed compression and 16 for low-speed compression. It also offers 16 clicks for low-speed rebound, and eight clicks for high-speed rebound with Fox’s proprietary VCC technology.

This post was sponsored by Fox Factory. 

ridefox.com

The post AASQ: What’s the Difference Between Air and Coil Rear Shocks? appeared first on Bikerumor.

We know, there’s no such thing as a stupid question. But there are some questions you might not want to ask your local shop or riding buddies. AASQ is our weekly series where we get to the bottom of your questions – serious or otherwise. Hit the link at the bottom of the post to submit your own question.

This week we are joined by hub design experts at Tairin Wheels, Onyx, TrailMech and Stan’s NoTubes, to take on a reader’s question about silent hubs. Aside from the absence of the sound of a swarm of angry wasps (which many folk are into), what are the actual benefits, if any, of a silent rear hub? Your contributors are as follows:

• Daniel Orellana, Jim Gerhardt and Shannon Hansen at Onyx Racing Products
• Jose Hsu, Design Engineer at Tairin Wheels
• Alexander Ivanov, Managing Director and Lead Designer at TrailMech
• Stan’s NoTubes – this was a collaborative effort from multiple engineers

Are there any advantages to a silent hub? Brands are going to great lengths to make quiet or completely silent hubs, but are there actually any durability advantages, or drag reduction to benefit from as a bonus?

Tairin Wheels: While there aren’t many designs of completely silent hubs out there compared to the abundance of ratcheting hub designs, a silent clutch design can be approached in many different ways. Aside from the benefits of being silent when freewheeling, one of the goals for a silent clutch design is to reduce the wear in the engaging mechanism, should it be a roller clutch, sprag, or an interference clutch with retracting elements.

The ratcheting you hear on standard hubs comes from the potential energy stored in the pawl or ratchet spring converting into kinetic mechanical energy in the form of sound waves. The first and most obvious observation is the energy loss, referred to as friction in the clutch against freewheeling; but another occurring consequence is wear at the point of contact. If the ratcheting element/geometry is the same used for engaging and torque transfer, eventually, at some point there will be significant wear to impede or lower the torque transfer rating. A slipping ratcheting mechanism most often leads to complete failure soon after.

For those that would say that they never had problems with wear on their mechanisms or ratchet rings, the effect of wear is more evident the smaller the teeth, the higher the engagement points in a revolution.

An interference mechanism with retracting elements is the approach we take in our upcoming silent hub design, where we separate the friction bearing element out of the engaging mechanism, with the benefit of silent freewheeling. Interference mechanisms, like seen in all ratcheting designs, offer the best weight to strength ratio for torque transfer. This is especially true in face gears (star ratchets), which are fantastic when the teeth are of adequate size, but can suffer from wear failures at a higher teeth count per same ring diameter (higher POE) just from freewheeling. With an initiator/retracting mechanism, the wear of the teeth is spared.

Onyx: There can be many advantages to a silent rear hub. Some of the feedback we’ve gathered over the years has aimed at silent hubs offering a more pleasant ride and connection with nature on the trail. This also allows the rider to hear all the other noises on the bike, albeit good and bad, such as tires working, suspension moving, brakes rubbing, and even cable rattle against the frame. 

The mechanical relation to a silent hub is usually the drag coefficient of the engagement system. At many times the rider is coasting/freewheeling and many high engagement hub systems have a large amount of drag in this motion from the pawl/ratchet assemblies moving over their engagement teeth. On the Onyx Design, the Sprag clutch glides on a smooth surface which provides minimal drag and gives the byproduct of silence. A lack of drag helps riders sustain speed and efficiency when freewheeling. Durability would not be related to the noise in our hub, but it may be on other designs.

TrailMech: One must be clear about what the term “advantage” means in this context. We will stick with these two: durability and reduced drag. And in both cases, there is no universal answer. It depends on the design. It is not possible to derive these characteristics based on a single attribute: silence. Indeed, it is also a characteristic of the design – whether the hub is silent or not.

Recently, there was an attempt to introduce retractable “ratchets”. That is, to completely remove whatever contact may be between ratchet parts in the disengaged mode. If there is progress with this approach – drag will be lower, compared with similar ratchet designs. Durability? Hard to say. One can think that ratchets themselves will do better. Possible, yes.

What about that retracting mechanism? How durable it will be? What about ratchets: how well they will operate? Especially at the “about to engage” point? Without an in-depth analysis of a particular design and its embodiment, it’s hard to tell.

On the other known design, there is a one-way bearing type. If one were to use bearings theory, drag losses depend on the bearing’s diameter. It is not the only component, but it does contribute there. The larger it becomes the greater the resulting drag losses. The diameter of such mechanisms is comparable, or larger, to the size of a typical bearing used in rear hubs. Thus, it’s like an extra bearing that one needs to account for from a drag loss perspective. We haven’t done our own study to suggest any real comparative data.

In our view – it is not obvious, to say the least, that such designs bring a benefit there. What about the durability of such designs? Even though hardened steel is the material of choice there, it still wears out. And we all know that weight is an important factor. Thus, making a part “beefier” as a way to drive up durability is hardly an option. Wear hardening caused by normal operations gradually kicks in. It may not render the part unusable but will affect performance. E.g. engagement angle increases over time. Again, one needs to put things into perspective. These systems are durable in our view. At the same time, we do not consider that the design “per se” offers higher durability.

Stan’s: The main appeal of silent hubs seems to be creating a more quiet, natural riding experience. How you go about making a hub silent depends on engagement type, subtle design features, and component qualities. Some quiet hubs drag more than some loud hubs, and there’s no actual correlation between noise reduction and drag reduction or durability.

With the new M-pulse, we didn’t set out to prioritize the sound. We thought some degree of “hub sound” was acceptable, with the main focus on exceptional durability, and relatively low drag. Form followed function for us, and function wasn’t silent.

Got a question of your own? Click here to use the Ask A Stupid Question form to submit questions on any cycling-related topic of your choice, and we’ll get the experts to answer them for you!

The post AASQ #156: Are silent hubs better? appeared first on Bikerumor.

We know, there’s no such thing as a stupid question. But there are some questions you might not want to ask your local shop or riding buddies. AASQ is our weekly series where we get to the bottom of your questions – serious or otherwise. Hit the link at the bottom of the post to submit your own question.

This week we’re turing our attention to the asphalt, looking at why road bikes with rim brakes and thru-axle wheels are a rather uncommon sight. To tackle the question, we have experts from Felt Bicycles and Argonaut Cycles. They are:

• Jeremiah Smith, Engineering Manager at Felt Bicycles
• Ben Farver, Owner of Argonaut Cycles

Why can’t I have a road bike with rim brakes AND thru axle wheels?

Felt: Another way to consider this question would be to ask, “Why do road bikes have disc brakes and thru-axles”? There is no technical reason why they could not have rim brakes and thru-axles or, alternatively, disc brakes and quick releases. Disc brakes with quick releases were utilized on mountain bikes for quite a few years. The push for disc brakes on road bikes came around the same time that mountain bikes were moving away from quick releases and to the 142×12 thru-axle standard. Thru-axles were developed for mountain bikes, as quick releases did not offer a stiff enough interface between the wheel and frame, especially on full-suspension mountain bikes.

Road bikes traditionally used 130 OLD (the distance between the inside faces of the dropouts, sometimes referred to as “spacing”) quick release hubs, while mountain bikes had used 135 quick release hubs. While there were some rare 130 disc hubs that were made for some early disc road and cyclocross bikes, they were not ideal. Because the disc brake mounting flange occupies a substantial area, the spoke flange has to move towards the center of the hub, which decreases the spoke angle and the strength of the wheel. The 135 OLD width hubs are wide enough to support a disc brake flange and still maintain acceptable spoke angles. (Note that 142×12 is the same 135 OLD width hub with different end caps for thru-axles.)

Road bikes could have moved to 135 quick release hubs, but because mountain bikes were already moving to thru-axles and all of the manufacturers were gearing up for that, we got 142×12 as the standard for all road and cyclocross bikes. While wheel changes aren’t quite as fast with thru-axles, they offer a much more robust connection between the frame and wheel.

So, back to the original question. “Why can’t I have a road bike with rim brakes and thru-axle wheels?” As I explained above, it is partially about timing and functionality. The timing part is that the push of disc brake-equipped road bikes came at a time when mountain bikes had, for the most part, moved to 142×12. Because it was an existing functional standard it was just adopted for disc brake-equipped road bikes. The functionality issue is that thru-axles never offered a significant enough advantage for road bikes on their own to cause the industry to move to it. The change had to come along with disc brakes as the primary driver.

Argonaut: From a performance standpoint there’s no reason you can’t run a thru-axle on a rim brake bike. It’s not like the axle interface would impede rim braking performance. In fact, it would likely be a big improvement.

But, no one makes a thru-axle, rim brake hub, that I know of anyway. I’m not sure if DT-Swiss end caps are swappable between their TA disc hubs and rim brake hubs, but I don’t think so. That being said, I can’t think of a reason you couldn’t build up a rim brake rim around a disc brake hub. You would have a rotor interface hanging out not being used that would be a little weird, but that would hurt anything.

You’d need a custom fork, though, maybe Wound Up would make one for you? The rear spacing is easier, but again, you’d need a custom frame that could take a 142mm x 12mm thru-axle. I bet Aaron at Mosaic would build you one! Haha. Where there’s a will, there’s always a way.

Got a question of your own? Click here to use the Ask A Stupid Question form to submit questions on any cycling-related topic of your choice, and we’ll get the experts to answer them for you!

The post AASQ #155: Why can’t I have a road bike with rim brakes and thru-axle wheels? appeared first on Bikerumor.

We know, there’s no such thing as a stupid question. But there are some questions you might not want to ask your local shop or riding buddies. AASQ is our weekly series where we get to the bottom of your questions – serious or otherwise. Hit the link at the bottom of the post to submit your own question.

This week, the good folks from Race Face, absoluteBLACK and Wolf Tooth Components are on hand to answer your questions on all things oval chainring. How oval is too oval? Does an oval chainring expedite wear on other components of your drivetrain? These questions and more are answered by the following:

• Technical Department at absoluteBLACK
• Doug Chalmers, Design Engineer at Race Face
• Kurt Stafki, Marketing Manager at Wolf Tooth Components
• Lori Barrett, Managing Director at Rotor Bike

What’s the advantage of a double-cam/twin-cam chainring over a regular oval chainring?

Editor’s Note: We did contact the folks at Cruel Components and Osymetric for comment on this but they weren’t available to provide a response at this time.

Wolf Tooth Components: Going to a more complex shape allows for further adjusting of the torque required based on the crank arm position, but this will lead to noticeable and unnatural transitions through the pedal stroke. While this may work fine in controlled environments (like trainers or a flat time trial), you don’t want abrupt changes when dealing with mixed surface riding – gravel, adventure, MTB, and most roads.

Also, to be clear, the mathematical shape used to define oval rings is actually an ellipse, which is why Wolf Tooth chainrings of this shape are called PowerTrac Elliptical chainrings. To nerd out a bit, all ellipses, which are defined as a curve on plane having two symmetric axes, are oval. An oval is defined as a shape that can have one or two symmetric axes. So, all ellipses are ovals, but not all ovals are ellipses.

Race Face: Oval chainrings work by changing the leverage on the chain through the crank stroke. The rider gets a more consistent force at the pedal through the whole pedal stroke. This means they can apply more force in the optimal power zone and less in the dead spots on the pedal stroke, reducing rider fatigue and helping to maintain traction on technical terrain by pedaling smoothly.

Race Face field testing has shown that slightly elliptical style oval rings are the sweet spot for most riders who want to try non-round rings. This relatively slight change in shape doesn’t result in having to learn to pedal all over again and typically results in improved traction and reduced fatigue without feeling odd when spinning fast on smoother trails at higher speeds.

There are specific advantages/disadvantages to more complicated variations of non-round chainring designs but there are technical challenges of meshing the chain to complex shapes as well as mitigating premature wear at sharper transitions on the ring perimeter. If they’re not overcome, there’s a higher potential for chain drop and short ring life. Low aspect ovals are similar to round rings in these respects.

absoluteBLACK: We can’t find any advantage. As a matter of a fact, it is rather the opposite. We have measured over one thousand cyclists in our laboratory (over time) with our state-of-the-art equipment ranging from amateurs up to the Winner of the Tour the France to study bio-mechanical movement. The shape of our oval chainrings comes from the scientific measurements and optimization rather than the “design” preference.

The shape was determined based on the output cyclists give to the pedals which differs between riding styles (e.g. MTB, road, TT) hence our MTB chainrings differ slightly in shape and timing compared to our road version. All of this requires a lot of bio-mechanical knowledge and a very unique tool to record 3-dimensional forces and torques at the pedals. In our Laboratory in Slovenia we have a bio-mechanical scientist and proprietary state-of-the-art equipment to do just that. More information can be found on our page under “science” tab.

Rotor: First, let’s clear up the difference between an oval ring, like the ROTOR Q Rings, and a double cam chainring: an oval ring has a single percentage curve (ovality) for the whole ring, where a double-cam chainring has a percentage ovality on either end with a connection in the middle that is lacking a matching curve.

Since the majority of studies show a greater benefit to oval Q Rings, ROTOR doubled down on this technology with our Optimal Chainring Position (OCP) system. This is a patented technology allowing riders to position the oval ring in accordance with their point of maximum power in the pedal stroke. With the ability to adjust the position of the oval, the rider is able to take full advantage of the reduction of drag in the pedal stroke’s dead spot and fully capture the additional leverage provided by the extended part of the oval.

Do oval chainrings put undue pressure on a derailleur clutch, thus leading to expedited wear?

absoluteBLACK: Well-designed oval chainrings have the same pull of the chain at every stage of the crank revolution. Our oval shape is a geometrical ellipse which means that no matter how you cut it through the middle it always produces 2 equal parts.

In real life however, there are some manufacturing tolerances on the crank – chainring connection resulting in small variation. This variation, however, is well within the engineered “play” of the clutch. We have been selling our oval chainrings for over 9 years now and still haven’t heard of a single clutch being worn out because of them. This is simply an unsubstantiated myth that is circulating on the internet since the clutch mechanisms entered the market and has been repeated ever since.

Wolf Tooth Components: This is a good question, but oval chainrings do not lead to expedited wear on a derailleur clutch. The beating that the clutch takes trying to control the chain over bumps far exceeds what a bit of cyclical movement does to it. There are some pretty great high-speed videos of suspension bottom-out that show how far the rear derailleur is whipped around–that is a worst-case, but imagine thousands of smaller impacts.

Rotor: While there can be a slight amount of movement in the derailleur cage with an oval ring, there is more movement demanded by variety of inherent bike movements, such as shifting on a standard round ring setup, a full-suspension bike moving through its travel, or the vibration accorded a hardtail or rigid bike passing over rough terrain. We have a number of customers who love riding an oval ring on a single speed cyclocross or mountain bike setup with no noticeable problems in chain tension.

Race Face: Depends on how sensitive the clutch design is. Most have a slight amount of lash that allows for an oval. Ovals do not vary the chain length as much as is commonly thought. The number of teeth on the chainring always remains constant.

However, a result of having a ring with a changing radius is a very, very small change of the angle at which the chain leaves the cassette and arrives at the chainring (and the distance the chain is having to span). An angle change of this amount has a nearly negligible effect on the total length of the chain between these points and does not result in excessive clutch use. It might be unintuitive, but it is possible to run an Race Face elliptical oval ring on a single speed bike.

How oval is too oval?

Race Face: This is subjective, but we have found that around 10% ovality is a reasonable number for most users, e.g., a 32t ring with 10% ovality has a major radius of a theoretical 33.6t round ring and a minor radius of a 30.4t round ring, a 3.2t total radius change). However, some riders run highly specific rings with parabolic paths, perhaps due to asymmetric leg injuries etc. And, some folks just prefer good old round rings!

In addition to ovality, timing must also be considered – relative angle between the major axis of the oval ring and the crank arm. The correct timing will depend on BB drop, seat tube angle, reach, and if the bike has an idler or not. Between 110-115° typically works for a standard drivetrain on an MTB with current geometry. Almost all MTB oval rings are in this range. Gravel and road rings may be different due to the different riding positions, so the rider is pushing on the crank at a different angle relative to the ground. 

Note: If you have an idler, you must rotate the oval forwards to match the angle of the chain arriving onto the ring, treat the idler as the “cassette.”  

Rotor: The studies we have consulted indicate there is a “sweet spot” of ovality, currently adopted at 12.5%. The point of an oval ring is not that one feels the oval, but rather that the pedal stroke becomes smoother with no conscious effort from the rider. It’s worth noting that the original ROTOR Q Rings ovals were at 10% ovality, with an option for QXL at 16%. After more research showed that we could improve upon the positive impact for pedal stroke efficiency, we adjusted all ring production to the more effective oval percentage of 12.5% and discontinued the rings that provided less advantage.

absoluteBLACK: There is no single answer that determines it because Ovality is a function of measurement and optimization per size and per intended use. It strongly relates to the first question. We performed over one thousand measurements and tested various ovalities throughout our development. We managed to determine the optimal ovality and timing based on objective scientific optimization.

As a rule of thumb, it is usually too oval (or not oval enough) if a designer does not have any bio-mechanical data from cyclists to base their knowledge on. There is also a second aspect that is just as important as the amount of ovality but sadly is often neglected. It’s the timing – when in the crank cycle the chainring has the biggest radius. You need to get those two aspects right in order to make a great oval chainring. 

Wolf Tooth Components: The fundamental idea behind oval chainrings is to translate human biomechanics into power for pedaling a bike. An oval chainring shape syncs natural movements with crank arm positions for efficient pedaling. When the crank arms are near vertical, you have less leverage and therefore you can’t transmit as much power to the pedals. An oval chainring provides more mechanical advantage in that portion of the pedal stroke, e.g., like having a chainring that is two teeth smaller.

Conversely, when the crank arms are near horizontal, you have more leverage and can transmit more power to the pedals. Based on those positions, you’d want a smaller chainring for when you have less leverage in the vertical crank arm position and a larger chainring when you have more leverage in the horizontal chainring position.

Our oval chainrings use a 10% ovality. With this shape, a Wolf Tooth PowerTrac Elliptical 34T chainring behaves like a 32T when crank arms are vertical and a 36T when crank arms are horizontal. This 10% ovality also offers optimized advantages of oval with the main ones being better traction and acceleration form a more even torque profile.

Am I more likely to snap a chain under high torque with an oval chainring as opposed to a round one? As the chain is cycled and, thus, the top chain line is pushed up and down relative to the ground, the amount of chain wrap around the cassette varies throughout the pedal stroke. Can this put more stress on the chain links?

Rotor: Short answer: there is no additional strain on a chain from using an oval ring. One of the metrics of increased performance on an oval Q Ring is improved pedal smoothness, which leads to more consistent and even application of power across the whole drivetrain, including the chain. Something that may be of interest in this vein; ROTOR power meters come with a free INpower software that allows riders to visually see their pedal stroke efficiency. It quantifies the smoothing of power output offered by a Q Ring.

Wolf Tooth Components: An oval chainring will not add any stress to the chain links beyond that of a round chainring. If anything, the chain will be stressed less with more even torque applied at the cranks (and thus more even pull force on the chain). When talking about the cassette, much like the clutch explanation, that chain is bouncing around already so the exact tooth engagement is dynamic from riding. Any additional movement of the chain from ovality as it comes off the top of the cassette is negligible.

absoluteBLACK: The amount of chain wrap does not vary on the cassette nor on the chainring in any meaningful way (comparing round vs oval). The angle of the chain leaving the cassette varies less than 2° – this is a negligible difference, meaning there is no correlation between the shape of the chainring and the likelihood of snapping the chain.

Regardless of the chainring shape, chains may snap in general if the quick link/pin was wrongly installed. But the most common cause is actually shifting under the full load. When a chain changes gears on the cassette under load, chain plates are pulled from an angle while being hooked only on 1-3 teeth, and this may lead to decoupling of the outer plate from the pin. So, the best way to avoid potential chain failures is simply to avoid shifting under load. During gear shifts just reduce the load on the crank for one full pedal revolution. 

Race Face: No. Race Face oval rings only increase the mechanical advantage of the rider in the portion of the pedal stroke where they are weakest, sometimes described as the “dead spot,” when the rider’s feet are at the top and bottom of their stroke. Using an oval chainring will typically result in more consistent chain tension through the pedal stroke compared to a round ring, due to the balancing effect of the ring leverage varying inversely with the rider’s power stroke position.

In answer to the question on chain-wrap, a change in chain-wrap of this small amount does not result in a notable change in the stress the chain links experience. The key is to have smooth transitions between each link, and a standard oval is one of the most efficient ways to do this on a non-round ring. 

Got a question of your own? Click here to use the Ask A Stupid Question form to submit questions on any cycling-related topic of your choice, and we’ll get the experts to answer them for you!

The post AASQ #154: Your Oval Chainring Questions Answered by absoluteBLACK, Wolf Tooth, Race Face and Rotor appeared first on Bikerumor.

We know, there’s no such thing as a stupid question. But there are some questions you might not want to ask your local shop or riding buddies. AASQ is our weekly series where we get to the bottom of your questions – serious or otherwise. Hit the link at the bottom of the post to submit your own question.

This week we’re taking on some serious suspension tech, delving into the world of rebound and compression damping adjustments. What actually happens inside the cartridge when you turn those external adjustment knobs? How does that change the suspension’s behaviour? Should you lock out your fork while climbing? What to do when the external adjustments simply aren’t enough? These questions and more are answered by the following experts:

• Giancarlo Vezzoli, Luca Rossi and Andrea Terzi at Formula
• Cornelius Kapfinger at Intend Bicycle Components
• Matt Hornland at FOX and Marzocchi
• Engineering Office at BOS Suspension

What actually happens inside a fork damper cartridge when you turn the compression and rebound dials?

BOS Suspension: In 75% of the technology, the clickers are moving a needle which has a cone form. This will affect the bleed section of the adjuster you are playing with. Some of the technologies have a valve and a spring. When you are changing the clicks, you are adjusting the preload of the spring and this will affect the threshold of the valve’s movement.
To make it simple, the adjuster offers more possibility to the oil for avoiding the piston and the shim stack resistance.

Intend: The so-called “Low Speed Adjusters” are only an orifice with adjustable size. But, the size does not change while you are riding. You can see that here on the example of my rebound assembly.

There is a small hole, which is open in the first picture (left) and closed in the second picture (right). The red adjuster on the inside is going to be threaded in when you turn your rebound adjuster.

FOX: The exact way this works will depend on your fork, but the simple answer is fluid travel is modified. Low-speed compression and rebound is usually controlled by using an orifice valve. This controls small amounts of oil that is allowed to flow freely around the shim stack. High-speed compression and rebound is usually controlled by using preload. This controls oil flow through shims that block ports on the piston by changing the force required to initiate the use of this valve. With something like FOX’s Variable Valve Control, the adjuster knob changes the leverage that the shim stack has over the leaf spring, instead of preload, reducing harshness as the initial force doesn’t change, but the slope of the damping curve can change.

Formula (Andrea Terzi): By turning dials in a fork cartridge, we can reach the best feeling for every condition and terrain with our bike. Technically, when we use it, we modify an oil flow that passes through a hole.

The mechanism of regulation is traditionally operated by a needle (conical or ogive shape) which flows in rectilinear motion controlled by a positioner. The more you turn the knob (in clockwise direction) the more the needle closes the hole.

This increases the pressure value with the result to force the oil to flow through the piston holes, elastically deforming the shim stack. Deforming shims requires more force instead of passing through a free hole, so for this reason we feel the fork is harsh when we close the compression register.

My fork doesn’t rebound fast enough at the low pressures I need to run to achieve the desired 25% sag. I find it packs down, even with the rebound set to fully open. What can be done?

Intend: In this case, the rebound tune is to hard for your riding weight. This is a common problem with stock suspension. Even if you have a high-speed rebound adjuster it can be that the rebound stack does not fit. In this case it is best you take it  to a tuning shop and get a proper setting according to your weight. Or you can simply use thinner oil in the damping. This also influences the compression damping, but is a cheap way to solve the problem. Or, you can buy an Intend fork. We can tune the fork based on your weight from the beginning.

FOX: Unfortunately, there isn’t a simple answer for this one. What fork is it? When was the last time it was serviced? There are lots of factors at play and they would benefit from speaking to a service tech at their LBS or touching base with a service tech at FOX about what they might need to do.

Formula (Luca Rossi): We know there are many riding styles and some riders don’t find the “perfect bike” until they adjust it for the way they ride. It is precisely for this reason that we also have a cartridge with a high rebound flow in the spare parts list. While you wait for the cartridge with faster rebound, though, you can try to change the CTS to get a more shifted damping curve at high speeds (like a blue or a red one) or add more than one NEOPOS to keep the fork higher.

BOS Suspension: Changing the clicks or the shim stack of the rebound will not always be enough in this case. Basically, you will have to change the balance of compression/rebound to be able to reach the right dynamic ride height with lower pressures in the cartridge or with lower spring rates. You will have to compensate for the lack of support from the spring by adding some compression damping rate.

Should I fully close the compression dial on my fork for climbing?

FOX: This depends on your fork and your desired ride quality. On a more technical ascent, we would recommend riding in trail mode, or slightly less than “locked out” to get the benefit of some bump compliance. If you’re climbing on the road or on a fire road, locking it out is great.

Formula (Giancarlo Vezzoli): I assume we are talking here about a fork (or shock) without a lockout; switching to a firmer compression helps if it acts on low speed damping. However, it is really unusual because actuating a compression knob is not really an “on-the-fly” operation; it usually requires the rider to stop riding and adjust. Moreover, some of the products on the market don’t have a compression knob, so the operation requires a tool (which hopefully you’re carrying all the time).

You will need to set it back before the descent, to a proper value (remember it or sign it on the suspension chart, usually present on the fork). That being said, we at Formula strongly believe in lockout, very firm actually: it drastically improves the climbing performance, and is available on almost all of our suspensions products.

The Formula blow-off valve prevents suspension damages even with the lock-out on, and furthermore saves you in case you forget to unlock it before a descent.

BOS Suspension: It depends how the dials affect the damping. If your fork is too stiff, you will lose stability on the uphills. The transmissibility in the frame of the holes, bumps on the ground will be too high. The aim of closing compression is to have a stiffer fork and avoid losing energy. An example, in hard slopes, at low speed, your fork should work to avoid wheelie.

Intend: You can do that, but there are no figures that show you can save a significant amount of power if you lock out your fork. If you are in search of a single Watt, then yes, probably. For the normal rider, it does not really matter.

Is there any reason not to run HSC and LSC damping fully open while descending?

Formula (Luca Rossi): Yes, if you keep the compression with zero damping (fully open) on the descent, in order to have support and prevent diving on the front you would have to increase the elastic force (air or spring). At this point, when the track changes slope and returns to the flat or uphill, you will find a vehicle totally unbalanced and loaded on the rear.

Intend: Depends on your fitness. Some riders say, they are faster with harder damping. In this case it is counterproductive to open your compression damping. But, more compression damping also means more fatigue on your hands. If you are riding the whole day in a bike park, it is nice to get the first two runs at full speed with hard compression, and then you are done and… in this case it is better for your average riding to open the compression to be able to ride the whole day, not only the first two runs.

BOS Suspension: There are no reasons at all to go this way. First, you lose the support that you can get from the hydraulics; this will affect the dynamic ride height a lot.

Secondly, and most importantly, softer doesn’t mean moire comfort. Your bike needs to have a minimum of damping. There is a range of damping where the suspension works best depending on the type of tracks. Being too soft or too stiff is uncomfortable for the rider and not good for the tire grip. You have to find the “sweet spot”. Getting the tire on the ground a maximum of the time and maintaining the ride height is the key.

If you are too soft you can have some overshoot of the wheel. This means your suspension will use more travel than needed. Your tires will spend lots of time in the air. The bottoming-out will be an issue as well. A the opposite end of the spectrum, if you are too stiff, you will transfer the energy to the chassis and your tires will be in the air for most of the time as well.

Why do forks come with such a massive range of compression and rebound adjustment when the vast majority of settings make for a completely awful ride feel?

BOS Suspension: The reason is to be able to cover a large panel of riders and track type. This will depend of the weight of the rider and the riding style, for example. As there are a large range of pressures or spring rates, the adjusters allow the suspension to adapt to the widest range of riders, even if each rider will use a small range of the adjusters.

FOX: At FOX Factory, we engineer and build race suspension. The massive range of adjustments are available to allow for the puzzlers and tinkerers to fine-tune their suspension through testing, training and observation. While not every rider will need this, we want our end users to have the same range of adjustment that our racers do so they can fine tune themselves; HSC, LSC, HSR, LSR, with clear settings to achieve the exact feel you want every time. It’s the same tuning philosophy we take.

Formula (Giancarlo Vezzoli): Suspensions are designed for a very wide crowd, with multiple riding styles, skills, weights, fitness, bike type and trail/terrain conformation, not to mention the temperature, altitude and latitude. The meaning of ample range settings is to let people find their preferred feeling, which is obviously not unique even in the same exact conditions. You surely have experienced the ride of your friend’s bike and judged it unusable. You for sure would need to change the settings between a hot summer and a freezing winter; the oil behavior, the rubber seals, the lubes in general work differently if you drop the temperature by 20°C.

Actually the adjustment range is never enough: indeed, people need to work on the shim stack in order to tune the suspension even more finely; that’s why here at Formula we introduced the CTS system, the simplest way of tailoring the suspension behavior without being a pro mech, at a very limited cost.

Intend: This is important to give the customer the feeling that the adjuster works.

Let’s take the following as an example: you buy a fork for a normal average rider weight of 70-90 kg and it has 4 clicks of rebound adjustment.

If you are 80kg, two clicks are perfect for you, and the fork feels nice. If you are 70kg or 90kg and you need 0 clicks (=open) or 4 clicks (=closed), respectively, to adjust it to your riding style. This may feel strange, though, because you get the feeling that you are already on the limit of the fork’s adjustments.

Really, you want to have the feeling, that whether you weigh 70kg or 90kg, that you can run 2 of 8 clicks as the lighter rider, or run 6 of 8 clicks for the heavier. In this scenario, you will feel you are more in the middle of the range, although you will never use 0, 1, or 7, 8 clicks (respectively). The possibilities give you confidence that you are in the middle of the range and the setting is a better fit for you.

Marzocchi: Simplicity is why Marzocchi has a more “set it and forget it” tuning philosophy. We don’t count clicks, and we think that more time fiddling with adjustments means less time shredding the trails. We keep adjustments simple with intuitive compression sweep, from locked-out to full open and simple rebound adjustment covers the range from fast to slow rebound for a full range of rider weights and preferences without over complicating things.

Got a question of your own? Click here to use the Ask A Stupid Question form to submit questions on any cycling-related topic of your choice, and we’ll get the experts to answer them for you!

The post AASQ 153: How do Suspension Rebound and Compression Damping Adjustments Work? appeared first on Bikerumor.

We know, there’s no such thing as a stupid question. But there are some questions you might not want to ask your local shop or riding buddies. AASQ is our weekly series where we get to the bottom of your questions – serious or otherwise. Hit the link at the bottom of the post to submit your own question.

Welcome back to the Bikerumor Ask A Stupid Question series. This week, we’re taking a closer look at the lesser-spotted usage of Truss Systems in bicycle frame design. One of our readers is interested to know why the use of trussing, in particular internal trussing, hasn’t been more widely taken up by the industry. To tackle this question, we’ve approached several frame designers who have, in various forms, used a Truss System in production of their frame. Having made use of Truss Systems themselves, they are perhaps best placed to comment on why this unusual frame design has remained, well… unusual.

• Sam Wilding, Director of Sales and Engineering at IsoTruss
• Ryan Johnson, Frame Designer at Galaxy Gear Works
• Bernd Iwanow, Frame Designer and Engineer at Frace Bike

Why is there no internal truss system in modern bike frames? Yes, we need to keep the surface smooth but why isn’t there more talk about individual strands of fiber taking a carrying load in a truss system? There could be potential weight savings in stiff areas like BBs and head tubes.

IsoTruss: Truss systems do offer advantages in weight and stiffness, but there are some challenges incorporating the truss system with the rest of the bike frame. First, some advantages. When it comes to hollow composite tubes/sections, the most efficient designs have thin walls and a large surface area. This makes the walls prone to puncture and such structures can be prone to shell buckling. Think of an empty soda can. You can stand on it, but the slightest touch to the wall of the can results in collapse.

With a truss system, individual members of the truss are more robust than the thin walls of the tube and less damage prone. The failure modes of a truss are typically easier to predict, too. Trusses are more efficient, from a strength-to-weight standpoint, than hollow tubes resulting in stiffer, lighter structures.

Now some of the challenges. The most pressing challenge, and the likely reason truss systems haven’t been adopted more readily, is manufacturing. The truss sections require complex manufacturing. Each section is made separately and then integrated with other frame components manually. This process is slow and expensive. For many, the additional cost doesn’t justify the boost in performance. Investment into better manufacturing methods would likely yield more consistent, less expensive products.

Galaxy Gear Works: First and foremost, any internal trussing/bridging/etc may be very difficult or impossible to accomplish in a meaningful or cost effective way on any production scale. The existing production methods that produce thin-walled metal tubing common in the bicycle industry (aluminum, steel, titanium, or otherwise) preclude the inclusion of internal features. While we can manipulate wall thickness with butting processes and shapes with various forming methods, we can only produce hollow tubes i.e. no trussing. Carbon tubing production as we know it in this industry would also (usually) preclude the creation of internal features whether the tubes are formed on a mandrel or inside a mold.

However… I have seen internal bridging in the steerer on a few carbon forks in the last few years. I don’t believe it is common practice. Why not, you might ask? Firstly, I’m certain that it’s an enormous pain in the ass to mold the steerer with a web dividing the tube. Layup precision and laminate compaction would be complicated to say the least. Bladder equalization and post-cure removal could also be significant hurdles. Here’s another thought that is perhaps the real reason why it is not common; a fork steerer has to meet certain structural criteria that perhaps define the wall thickness to a degree that an internal web/bridge is superfluous. Shear and bending forces at the fork crown aside, the top of the steerer tube has to resist the clamping forces of the stem and ham-fisted mechanics.

Even supposing everyone ritually abides by the manufacturer’s torque specifications and uses a torque wrench to install the fasteners, it has to withstand a fair bit of crushing force. Add the real-world stresses with the “fudge factor” that the engineer calculates in there to keep the lawyers happy, and the steerer has to have a pretty hefty wall – certainly burly enough to handle normal torsional, shear, and bending loads as well.

The steerer also has to have that “hefty” wall thickness through so much of its length to accommodate the stem clamp height for an extreme range of bike sizes, assuming a production fork. So… does it really make any sense for internal trussing/webbing/bridging on a production made fork? In my opinion, it would require too much effort for far too little reward. I don’t believe it could add measurable performance benefits or reduce weight at a meaningful level.

I have also seen a few examples of internal features on steel bikes, and I’m currently riding an MTB with internal bridging in the chainstays. The point of the aforementioned features is stiffness. Dario Pegoretti created the Big Leg Emma with a series of flat sheet bridges in the downtube. They are inserted into slots cut into the sides of the tube, brazed into place and covered with a tidy, brazed-on gusset. You can see these features clearly on the model page on the Pegoretti website.

The tubes on this bike are fairly large in diameter for steel tubing, and I’m sure that the walls are pretty thin. In my opinion, the bridging plates are long enough (in reference to the long axis of the tube) to act as a truss to increase the tube’s resistance to side-to-side bending forces i.e. all-out sprinting for city limit signs on Tuesday nights. How much stiffer is it due to these internal features? I have no idea. It could be measured of course.

My current MTB was built as a “shreddy hardtail” so it needed to be somewhat burly. Strength and stiffness were paramount, and those attributes had to marry with a kinda short chainstay length and 2.8″ tires. With all that in mind, the chainstays were pretty narrow where they were formed around the tire. I felt like this narrow cross section wasn’t going to produce enough lateral stiffness in the stays.

Part of my concern was the real possibility of tube deformation and bending under pedaling loads. Like the advantages I believe to be present on the Pegoretti downtube, I think I added strength and stiffness to the tubes by adding horizontally oriented plate bridges across the interior of the narrow, forward portion of the stays. I executed these additions by slicing the tubes, inserting the sheet-metal plates (about four inches long), and welding the plate’s edge along the tube intersection.

Now we ask the question, “was it worth all the effort?” I don’t know the answer. I didn’t do any lab type testing or calculations. I’m no engineer. What I do know is that the bike rides well and is going strong after more than two years of hard riding. I also know that I damn sure didn’t save any weight by adding those bridges.

Is it possible that internal bridging/trussing could allow thinner walls on the tubes? I’d say heck yeah! How would we do it? Perhaps 3D printing somehow rather than laborious hand work or a combination of both? And would it come at a cost to durability and therefore practicality? The answer might be yes. Use the massive, but not surprising proliferation of carbon repair services springing up all over the country now that the volume of out-of-warranty carbon bikes has reached critical mass as evidence. The tubes on ultralight carbon road bikes don’t need to get much thinner unless we see more volume of tougher materials like Dyneema incorporated into the laminates. That stuff is expensive though!

In the real sense, internal trussing does not commonly exist in this industry. With carbon production frames routinely coming to market below 900g, is there really a need to try and make them lighter? I’m not sure. And more often than not, these ultralight bikes are plenty stiff thanks to high modulus carbon and smart laminate engineering.

Frace Bike: A tube compared to the truss system is having always less weight for having the same stiff characteristic. So it is for sure more weight saving to have a tube – but it is also a lot more boring. Everybody is doing tubes – but we want to have something different from all the others. And, for having a fully milled frame out of aluminum there is no other opportunity than choosing such a style as the truss system. But this truss system is more expensive – but it is looking great. Sure you have to pay more but then you are getting a unique style.

Got a question of your own? Click here to use the Ask A Stupid Question form to submit questions on any cycling-related topic of your choice, and we’ll get the experts to answer them for you!

The post AASQ #152: Why is there no internal Truss System in modern bike frames? appeared first on Bikerumor.

We know, there’s no such thing as a stupid question. But there are some questions you might not want to ask your local shop or riding buddies. AASQ is our weekly series where we get to the bottom of your questions – serious or otherwise. Curious about something? Submit your own question.

Welcome back to the Bikerumor Ask A Stupid Question series. This week we’re talking about carbon fork design. The chances of a carbon fork actually breaking on you are extremely slim these days, and manufacturers go to great lengths with their modeling and quality control methods to ensure that is the case. Nonetheless, given some well-publicized historical cases of carbon fork failure, we’re aware that some riders still see this as an area of concern.

After receiving some poignant questions from one of our readers, and with the growth of integrated designs funneling brake hoses and shifting wires in and out of a steerer tube and fork leg, we thought we’d bring in some experts.

Two bike brands chimed in to discuss carbon fork design, and in particular, the possibility of a steerer/headset/stem interface redesign with full stealth cable routing in mind. Your experts are:

• Marcellus Putschli, Product Engineer at Bombtrack Bicycle Company
• Charlie Ward, Test Engineer at Scott-Sports

1. Would it be possible to design a headset and carbon steerer system that doesn’t use a compression ring and otherwise minimizes damage from over-compression by those who don’t use torque wrenches (surprisingly many of them), stems without a full-coverage clamping surface, grinding away by internally routed brake/shift hoses and cable housings, and cumulative minor impact forces to the steerer (riding over railroad tracks, potholes etc.) which can weaken it over time.

Scott: It could be possible. There are many aspects of design yet to be explored and many that have already been used to good effect in the history of bicycles. As we see it, this is currently the best assembly method to ensure efficient steering, rider safety, and compatibility of parts.

Any mechanical joint, and especially those that use bearings, are sensitive to assembly torque, and therefore preload on the bearings. It is really unavoidable for a lightweight structure like a bike to be designed to sustain unknown assembly torques. The other aspects you mention are all considered in the engineering phase of our developments, and we follow the international standards and have created our own standards to make sure our bikes stand the test of time.

Bombtrack: This is a hard to answer question, as it already implies a certain direction to the solution of the problem of carbon steerer breakage. I would rather, ask if we need to reduce safety margins for low weight, or offer a very labor and QC-intense product for a low price point before introducing a new stem/headset/steerer interface into the bicycle world that is not short of various competing standards.

But to answer this question: Yes, of course it would be possible to design a completely different system. The current headset/stem interface was developed with aluminium or steel steerers and stems in mind. It is not optimized for the use of fiber-reinforced materials, as the force applied hits the fibers orthogonally. So, developing a new interface would offer a lot of benefits, but it will come at a cost.

To be really suitable for the use of composite materials it won’t be backwards compatible with the current stem/headset/steerer interface. This will also mean that various manufacturers will have to work together, so that headsets/stems and forks are available at the same time, otherwise such a system won’t be accepted by the market. In the end, I am not convinced that the benefits will justify the introduction of such a new standard.

However, I don’t think we need to go that route right now. A lot can be done to make the current interface safe, even by the consumer after purchasing a bike (of course, first of all those things should be done during production). Deburred edges, correct internal cable routing, friction paste for carbon stems, a sufficiently long expander, correct amount of headset spacers, and the use of a torque wrench should be self-evident for production, shops, and home mechanics.

Sufficient safety margins and proper quality control need to be implemented by the manufacturers. Of course both will come at a cost: Bigger safety margins result in extra weight, and higher-level quality control adds cost that trickles down to the retail price. Unfortunately, both these factors shrink the viability of a product, especially that of carbon parts since they are already expensive and offer great potential for weight savings.

Also, carbon parts need to be professionally inspected or replaced after a crash (sorry, this also includes the random tip over at a coffee stop). A properly designed and maintained fork won’t suffer from cumulative minor impact forces, at least not during the normal lifespan of a bike.

2. Why don’t manufacturers bond or in-mold a thin metal sleeve over the carbon steerer where the compression ring, stem, and bearings contact it, to strengthen the steerer and improve its longevity?

Bombtrack: This is a method that would add cost, complexity, and weight to the production of a fork while reducing the outer steerer diameter (the part of the steerer that is most relevant for stiffness). It is not necessarily a bad method, as it helps to distribute the load, but again it will come at a cost.

Personally, I would rather optimize the other parts of the system than reduce the wall thickness of the steerer in the area of its maximum load. Also, most carbon forks will come with a set steerer length that gets cut down to its correct length during the assembly of the bike. This means a metal sleeve needs to be long enough for all possible headtube lengths, so it will be much longer than necessary on a taller frame. All things considered, it seems that this solution works rather as a patch than tackling the root cause of the problem.

Scott: We do use inserts already in the dropouts or brake mounts for example, but in those cases, they can be fully enclosed in carbon with the fibers running around both sides of the part. In-molding metal sleeves in a steerer tube is very difficult to do in a way that improves the resistance to wear without drastically reducing the strength.

A sleeve on the outside of a steerer would mean that the carbon fibres would have to either be cut to insert the sleeve, or molded around the sleeve, both of which would reduce the strength of the steerer. If we consider the transmission of forces into the steerer, then reducing the number of parts in between actually improves the situation; having a direct connection between the carbon bar/stem combo and the steerer tube gives the best possible stress distribution. Adding a metal-to-metal contact between the sleeve and the bearing could also introduce the danger of corrosion and frictional effects such as fretting. 

3. Why don’t manufacturers check every fork with a scanner to test for voids and other defects you can’t see (as far as I know Canyon Bikes does this)?

Scott: CT scanning is a great method to identify flaws in carbon structures. The machines that are available now are really impressive, but also limited in terms of what they can achieve on a mass production scale. If you really want to get a detailed scan and see defects in the structure on a sub-millimetre scale over a whole fork, for example, each fork needs a long time in the machine resulting in a huge amount of data that needs to be processed, analyzed, and stored.

This requires some substantial computing power and staffing which at the current point is not possible to implement without a significant price increase for the end product. It is an invaluable system that we regularly use in development and research, but we have a high level of confidence in our production methods and QC, so the chances of having critical defects in an end product are kept to an absolute minimum.

Bombtrack: Quality control is important, but it doesn’t help against design flaws, so unfortunately a scanner won’t guarantee that a part doesn’t break. With that said, there are various methods of ensuring proper quality during the manufacturing process, for example keeping track of the weight of the used materials, measuring the stiffness of the product, checking the geometry, doing x-rays, tap tests, and ultrasonic scans as well as CT and thermographic scans. All of those methods are non-destructive and can be used during various stages of manufacturing.

Another important aspect is the skill level of the workers, the quality of the tooling, the quality of the resin, storage of the raw material, and air temperature and humidity in the factory as well as following the exact layup plan.

All of the described methods have their pros and cons, and while a CT scanner is a very impressive machine, it only helps to spot mistakes already made. Designing material-specific, adding sufficient safety margins, and investing in a skilled and consistent labor force while keeping close track of all manufacturing steps helped us to avoid any major fork defects. In addition, we do a third-party quality control and regular destructive tests. So far, we haven’t had any fork or frame recalls. 

4. What else can be done to re-design the carbon steerer-headset system so we can all ride carbon forks safely for years, in real-world conditions? I would gladly add 100-150 grams for a stronger and more durable carbon fork I know I can depend on for years. And I think most of us would. Thanks!

Bombtrack: The answer lies within the question. There is no free lunch, if you want a safe carbon fork don’t shop for the lightest fork and especially not for the lightest compression cap. If you really need to have a very lightweight fork then be prepared to pay the price. Not only the purchase price but also the cost for proper tools, a good mechanic, and the replacement or scan in the case of an accident. If you want to have a worry-free fork that can take a beating then maybe a steel or aluminum fork fits your needs better than a carbon one. Don’t forget, weight is not everything. 

With that said, I think getting rid of the expander and increasing the contact area of the stem will both have the biggest potential to increase the durability of the stem/steerer interface. There are already several systems available that don’t rely on the expander to adjust the correct headset play. And, when most riders add spacers underneath the stem while having to add a 5mm spacer above the stem as well, it would make much more sense to integrate those spacers into the stem and increase the clamping area by 15mm or 20mm.

Scott: SCOTT is very proud to still have many of our older models still out in the market and rolling without issues many years on. I’d still emphasize here: real-world conditions are very difficult to predict. We always consider what we call ‘foreseen-misuse’ in our engineering and design, and it is one of the reasons that mass production carbon bikes can’t be as light as some boutique brands. One person’s gravel is another person’s XC, but SCOTT strives to be very clear with what each of our bikes are built to withstand and make sure our test standards consider the harshest use cases.

Got a question of your own? Click here to use the Ask A Stupid Question form to submit questions on any cycling-related topic of your choice, and we’ll get the experts to answer them for you!

The post AASQ #151: How can we design better, safer carbon forks? appeared first on Bikerumor.

We know, there’s no such thing as a stupid question. But there are some questions you might not want to ask your local shop or riding buddies. AASQ is our weekly series where we get to the bottom of your questions – serious or otherwise. Hit the link at the bottom of the post to submit your own question.

Welcome back to the Bikerumor Ask A Stupid Question series. Happy New Year, folks! This week, we take a look at how rubber compounds and tire pressure are affected by temperature – a timely topic as winter takes hold here in the Northern Hemisphere. We also have an unrelated bonus question on why motorcycle tread patterns contrast to that of mountain bike tires. Your experts are as follows:

• James Heaton, Marketing and Public Relations at WTB
• Robin Schaub, Product Engineer at Onza
• Ken Avery, SVP Product Development at Vittoria
• Robert Mennen, Product Manager at Schwalbe
• Samuele Bressan, Global Marketing Manager at Pirelli

Will sub-zero temperatures negate the grip benefits of running a soft compound MTB tire versus a harder compound version?

WTB: Generally, colder temperatures will mean colder rubber, and colder rubber means harder rubber. If you already have a hard compound tire to start with, then you can expect that compound to get a little harder as the temperature drops. A soft compound will also get harder when it gets colder, but it will still stay softer than the hard compound at the same temperature.

Basically, the softer compound is still the softer compound, regardless of temperature. Back to the original question then… We’d say the answer is nope. Sub-zero temps won’t negate the benefits of a soft compound vs a harder one.

Vittoria: When used in a normal temperature range, softer compounds allow the tire to conform to terrain and increase grip. However, when the temperature drops, most rubber compounds get slightly harder, reducing the effectiveness. This can be especially true of summer performance compounds, which tend to be actually more sensitive to colder temperatures when compared to more standard durometer compounds. In extreme cases, super soft compounds can actually become harder (and less grippy) in cold weather, compared to the standard compounds.

For example, we can look to the automotive industry, and studies done on stopping distances in cold weather environments. In these studies, winter specific compounds typically stop in a distance that is up to 50% shorter than summer compounds. 

Schwalbe: While temperature definitely affects tire performance, there are some compounds like our Addix compounds that are less prone to this. For instance, the differences between our Addix Ultra Soft compound and Soft compound stay valid also for cold weather.

All of our Schwalbe Addix Compounds are rather insensitive to temperatures in usual conditions (from double-digit minus degrees to summer temperatures) and have a significantly lower glazing temperatures than some of our competitors. This is the reason why our tires work well under a wide range of conditions. Nevertheless, it is absolutely beneficial to run the Ultra Soft compound in these conditions as it’ll still provide a performance benefit in terms of grip and damping and thus safety in these conditions.

Onza: Most tires designed around natural rubber are affected by colder temperatures starting at around 7 °C, becoming less pliable and unable to mold to the surface as well. Synthetic rubber compounds have a higher tolerance and maintain much of their softness and traction across the surface but are still impacted by < 0 °C temperatures (just not as much as natural compounds).

By carefully fine-tuning our rubber compounds we are able to minimize the effect of low temperatures, however it’s impossible to completely get rid of the effects that come with temperature change. Generally, we recommend running a softer rubber tire in winter if you’re not already on one. Other options involve dropping a few bar/PSI or trying out a wider tire for an overall larger surface area to help the tire track better.

Pirelli: It really depends on the compound formulation: all the compounds have a characteristic curve of properties vs temperature. There is a temperature named Tg (Glass Temperature) below which compounds start behaving as glass. Around that temperature stiffness and hysteresis suddenly increase, making the compound lose performance and become extremely fragile. In Fig.1 you can see two different compounds (blue and red) and how stiffness (dashed line) and hysteresis (solid line) change around the Tg, which are in the peak of the solid lines.

Compounds are designed to work sufficiently on the right of the Tg (oval area), where properties are almost constant
It is true that, generally, the compounds become stiffer with lower temperatures, but, if they are designed with a very low Tg and a sufficiently wide temperature-usage-spectrum, these differences can barely be perceived.

Winter compounds have a lower Tg and the temperature-usage-spectrum is generally shifted toward colder temperature with respect to summer compounds (Fig.2, colors are not related to Fig.1).

Of course, there might be a compromise, in fact, if a compound work on a too high temperature, it become softer and softer, causing a premature wear.

This to say that, negative effects on MTB compounds due to subzero temperature really depends on the compound formulations. It is true that a compound might become stiffer and rebound can become slower due to low temperature, but different compounds may be more subjected to this effects than others

How will the cold weather affect my tire pressures? 

Onza: Typically, a tire will drop air pressure in colder temperatures (although the ratio does not align with the previous question on subzero temperature effects on rubber, so don’t count on these effects to cancel each other out). The rule of thumb is that per 10 °C, a tire will lose 1 PSI of pressure. This is not a significant adjustment, especially compared to an effect such as altitude changes on tire pressure, but it can still be noticeable and for riders sensitive about their tire pressure, this is something to keep in mind. We recommend checking your tire pressure before every ride.

Schwalbe: At constant volume, temperature and pressure are proportional to each other. A temperature drop of 20°C can lead to a tire pressure that is 0.1 – 0.2 bar lower for a tire in size 29 x 2.4”. When wetness is added a lower pressure can be beneficial: the speed in the wet is lower so there is reduced force transmitted into the tire which allows you to run lower pressure so you benefit from a greater contact patch for improved grip and better damping.

Vittoria: I get asked this question more than I would expect, so thanks for asking it for the article. I suppose you could say that the temperature will affect the pressure, but honestly, I always advise to check and adjust your pressure before each ride anyway, so the effect shouldn’t really be a huge concern, since you are adjusting it as needed.

My personal take on this is, if the terrain is more slippery, then drop your pressure (to increase grip) until you find a new sweet spot. However, as mentioned above, the compound may limit this, so adjusting pressure (alone) will likely not give the same performance you were used to in the warm weather.

WTB: Cold air is more dense than hot air, so as the temperature drops you may want to slightly drop the pressure to get the same feel. In fact, you may even want to drop your pressure a little further if you’re struggling for traction. Colder temperatures can mean both harder rubber and more slippery terrain too, so dropping pressures a touch will help you keep traction.

Pirelli: Usually, cold weather pushes the riders to choose lower pressures for different reasons:
• Generally, cold weather is related to slippery conditions. It is easier to bump into a shade area where the terrain is wet or even frozen, with a sudden reduction of grip
• With the tyres made of different compounds and materials, sometimes the properties discussed in question 1 make them a bit stiffer
• Usually in winter riders prefer to have more fun, be safer, even a bit slower, than in spring or summer

It is clear that a lower pressure improves grip and comfort, even if rolling resistance and quickness may be worse. Due to worse terrain conditions, speed is usually lower and, consequently, also the impacts with obstacles. Therefore, the risk of suffering a pinch flat due to the low pressure is reduced and a lower pressure is preferred. For the same reasons, the riders usually prefer higher knob tyres with softer but a slower rebound rubber compound for the cold season.

Why do Moto and Bicycle front tire chevrons point in opposite directions? The pointy end of the “V” points forward on bicycles and backwards on motorcycles.

Vittoria: Tread depth and knob spacing have a lot to do with this. The old chevron direction (to dig or to scoop) has long been a topic in tread design. On a bicycle, there is an emphasis on light weight, and low rolling resistance. In a super simplified sense, here is a brief overview:

With the chevrons pointing forward, the knobs (or grooves) of the tire will form a row (or a little wall). This wall opposes the potential slip direction of the terrain during cornering. With a reverse chevron design, each knob (or groove) also is positioned to form a row or wall. However, this wall aligns with the potential slip direction, such that the effective edges of the knobs are situated one behind the next. Which is the right answer? As always, it will depend on the terrain, and application.

For example, on mountain bikes (used off-road), the forward pointing chevron is effective to dig into corners, and oppose under-steer. On road-going motorcycles, the reverse chevron is particularly useful in water dispersion on tarmac.

WTB: Actually, that’s not the case for WTB treads. The Nano is a ‘forward’ V, but the Vigilante is a ‘reverse’ V. How the tread looks is only a result of designing a tread for optimal performance, rather than something that is designed specifically. Tread design is always about making the tire perform well. If it looks pretty, then that’s a bonus.

It’s worth noting though, that rolling resistance is not too large of a concern with moto tires as they have a big old engine pushing them forwards. On a bicycle you can directly feel the benefit of a tire that rolls quickly with every pedal stroke, so how fast a tire rolls is very important. Forward V designs generally roll faster than reverse V treads. Hope that answers you’re question!

Onza: This question can be re-framed to: why have directional tires in the first place, and what is their purpose?

Generally, for both bicycles and motorcycles, the rear tire is delivering the power to the ground, while the front tire performs most of the braking and takes all the steering forces. Motorcycles, just as bicycles, differ in their applications and are subject to varying terrain. The traditional v-grooves on a motorcycle street tire are not necessarily indicators of direction. Tire manufacturers design tires to work as a system for the front and rear.

Sticking with motorcycle street tires, the Vs face each other: the rear tire V faces forward (>>) to propel the motorcycle forward and hence twists in a way to “push” the tarmac behind while the front faces backward (<<) to propel water away from the tracking area and “push” the tarmac in front.

The V trajectory on a bicycle (especially for road tires) differs from that of a motorcycle in that the V tread-shapes face forward (>>) for both front and rear. This has mainly to do with rolling resistance, although tests show this only applies to mountain bike tires, where the tread is more prominent and impacts rolling performance more. Of course, on a bicycle, the rules are more open to interpretation as the forces front and rear are not nearly as powerful as on a motorcycle, but there are still very important differences in application and manufacturers have good reason for specifying direction, namely, to give the rider optimal performance in speed, traction, and durability.

The so-called “sipes”, small grooves in the knobs of off-road tires, are arranged in the direction of the forces acting on the tire in the respective load case. In the case of the side knobs, these are forces from the side, while the center tread gets loaded in the direction of travel. By incorporating sipes in the tire design, we can influence how the tire deforms under load and ultimately increase grip and braking performance in the right areas.

In either case, for both bicycles and motorcycles, it is very important to mount a tire as specified by the rotational arrow, which is always marked on the tire’s side wall.

Schwalbe: For cars and motorcycles, for optimal water displacement to prevent aquaplaning, the “V” should point forwards, so that the top of the “V” hits the ground first and water can be displaced to the sides. As far as we know some Moto tire manufacturers changed the direction of the “V” because otherwise the tread can become some kind of saw-tooth profile with reduced durability.

Both cases are not really relevant for bicycle tires, especially MTB tires. So, when we design tread patterns we take into account the field of operation and concrete requirements for the profile. Our Schwalbe Magic Mary and Big Betty use side knobs that have a “V” pointing backwards. We found out that this design in connection with the general tread pattern of these two tires offers some benefits for controllability while cornering. For other tires, a different shape has proven to be advantageous, for example the Racing Ray or Racing Ralph. It depends on the overall tread pattern and must be adapted to it.

Pirelli: Grooves on tyres have different purposes, whether they are for bicycles or motorbikes or cars:

1. Evacuate water, especially motorbike road tyres. In the case of the bicycle, this is neglectable as bicycles tyres are not affected by aquaplaning. They are very narrow and speeds are lower than the ones which might cause aquaplaning with such a narrow footprint.
2. Give proper behavior to the footprint. A grove (or a sipe) make the compound behave in a “softer” way in that particular area due to deformation (which is a design parameter of the engineers when they define the desired performances and that is linked to the rubber’s mechanical properties too).
3. Mechanically grip the terrain, especially for all terrain tyres, supposed to be ridden in harsh conditions.

These are the general criteria. The factor that comes into play to differentiate the choices made by the designers between motorbike and bicycles is mainly the overall mass (so the weight) difference of the two vehicles, and so the resulting forces that effect the tyre’s behavior.

On a bicycle, forces are way lower than what we see on motorbikes, and wear occurs mainly on the rear wheel and on the center of the tread, due to traction. Wear is not an issue for lateral groves. Therefore, the usual choice is to go for the best mechanical grip in braking (point 3. of the above list). Furthermore, considering the smaller dimension of bicycle tyres with respect to motorbike tyres, the roughness of the asphalt or the dirt on the roads has a bigger impact on the grip and handling of the bike, making the choice of going for more mechanical grip (point 3 as said) the winning one.

With respect to motorbikes, the tyres are subjected to much higher and different forces, especially when leaning:
• FRONT: Braking + Leaning (blue arrows)
• REAR: Acceleration + Leaning (red arrows)

The magnitude of those forces that happen at the rear wheel (accelerating out of a turn, when still leaning, is quite common) and in the front (braking into the corner, so with high mass that puts pressure on the side tread) are way higher, and need to be addressed also mechanically. As a result, the average stress vectors follow the groves’ direction (in the above picture for the left side, it is symmetric on the right).

In the center, the vector is aligned with the tyre rotation, only traction or braking with the straight bike. Going towards the shoulder, the leaning component is higher and higher, resulting in a more radial stress. In fact, it is quite improbable to brake or full throttle in while leaning a lot.

If the rotation was opposite, the vectors would be perpendicular to the groves. This would enhance mechanical grip (point 3.). In fact some on/off road tyres have an apparently opposite rotation for the front tyre with respect to road ones.

However, these situations can lead to uneven grove wear, causing unpredictable and dangerous leaning behaviors.
Here’s a visual example of a cross-section of a groove that has edges uniform and even, and an example of what happens when the groove edges are charged perpendicularly (the case of a motorbike tyre mounted with the arrow pointing forward, as if it were a bicycle).

Got a question of your own? Click here to use the Ask A Stupid Question form to submit questions on any cycling-related topic of your choice, and we’ll get the experts to answer them for you!

The post AASQ #150: How is tire rubber and tire pressure affected by cold weather? appeared first on Bikerumor.

We know, there’s no such thing as a stupid question. But there are some questions you might not want to ask your local shop or riding buddies. AASQ is our weekly series where we get to the bottom of your questions – serious or otherwise. Hit the link at the bottom of the post to submit your own question.

Merry Christmas, folks! Welcome back to the Bikerumor Ask A Stupid Question series. This week we have a really interesting question from a reader about custom shock tuning. We often see mountain bike brands make a big deal of their custom shock tune in their press releases, but what does that actually mean, and how do they decide on which specific damper tune is best for their bikes? We went to mountain bike brands and suspension manufacturers in a bid to find out a bit more about the shock tune development process from both sides of the equation. Your expert contributors this week are as follows:

• Ken Perras, Rocky Mountain Product Manager
• Adam Miller, Owner and Frame Designer at Revel Bikes
• Jochen Forstmann, Founder and Co-Owner of LAST, General Manager and Head of R&D
• Matt Hornland, PR & Marketing Content at FOX
• Sofia Porfirio, Head of Marketing at Formula

Custom Shock Tuning from the Frame Designer’s Perspective

Rocky Mountain: We start the process by sharing suspension rate information with our suspension suppliers. This allows them to develop damper tunes that they feel would be best suited to our kinematic, and serves as the starting point in the shock tuning process. The next step can vary depending on the type of frame development.

In the event that the suspension or shock platform is all new, and previous tunes and ride experiences do not carry over, we typically set up a comprehensive tuning session, that can span days if not weeks. This allows us to test a wide range of tunes and setups to determine an optimal tune that we feel best suits the intended use of the suspension design. This process also encompasses the different tunes we offer on some frame sizes, or helps validate the use of the same tune on the different kinematics we offer on our smaller sizes.

After that initial test session, more riding is performed on the new frames and shocks to validate the settings we achieved. Sometimes we need to make adjustments with the suspension supplier. This can be due to factors such as testing in new terrain or in different weather; hot/cold temps and extreme conditions such as dry, hard pack or muddy terrain can make it difficult to achieve our initial goals. In other cases the supplier has made internal hardware updates that could affect the shock tune, so we need to revisit the settings to ensure they are still applicable.

Finally, after the testing period, we need to settle on tunes and have part numbers created for orders. This doesn’t necessarily mean that shock tuning is over as we can gain new insight with more ride time, and apply that knowledge to the following product year. We are constantly evaluating our tunes and collecting feedback from our staff, customers, race team, etc., to ensure that we have the most optimal tune we can get. The work is never done!

Revel Bikes: This is actually a fantastic question! This part of the bike development process is often overlooked or not talked about much, but it is one of the most important. If you get a perfectly designed full suspension bike but with a shock that is not tuned properly, you might as well have saved all your money and stuck with a hardtail in the first place.

Generally, when we design a bike, we start with the geometry, desired suspension travel, and different frame features. Then we work with Chris Canfield to lay out the suspension kinematics, and that’s where a lot of the magic happens. Once we’ve got those dialed, we send a leverage curve to our suspension suppliers, and they take their best guess at the proper tune for the bike.

By the time we get rideable prototypes, we get to do the most fun part of new bike development and test ride them like crazy. I could talk for hours about our ride testing processes and how we do blind testing with different carbon layups and shock tunes and secret ride test feedback forms with a curated group of riders from within our company and out of it, but we can save that for another discussion… the bottom line is we make sure that the shock manufacturer’s best guess is correct.

We’ll generally try some tunes outside the ones that they recommend, too, so we can be extra confident that the shock we’re bolting on our bike makes the suspension perform to the best of its abilities for the widest range of riders and terrain. Since we’re lucky enough to have crazy technical Sedona-style trails a couple hundred yards from our office at Red Hill here in Carbondale, we can do a whole lot of good ride testing really easily.

The only downside of our location is we get a whole lot of snow in the winter, so if the development timeline and shock tune testing falls during the winter months, we usually make a trip to Grand Junction or Moab and try to ride several different types of terrain on those shocks. The supply chain challenges and parts shortages have affected even this aspect of bike development- in the past, it was easy to order 10 or more shocks with different tunes from different manufacturers and try them all out at once.

Now, since fewer shocks are available, we have to be a lot more confident up front and only order a few different shocks. Luckily, after a few years and several CBF bike models and Chris Canfield’s suspension expertise, we’ve gotten pretty good at nailing shock tunes on the first or second try. Also, if bike manufacturers recommend a certain tune for a shock, I definitely recommend following that advice and not trying something different – the bike will usually ride much better! Overall, shock tune testing is super fun and it makes for a good excuse to get a few extra lunchtime product test rides in.

LAST: Deciding which shock tune is the best for a certain bike is a hard one, especially when starting from scratch. Fortunately that’s almost never necessary because everyone is evolving their portfolio of shocks and we are evolving our frames incrementally as well. Even if frame designs might look totally different, they carry over a lot of the kinematic principles.

At LAST we like very progressive kinematics. Each of our frames is really progressive, with small alternations for the intended purpose. This shows in the leverage ratio curves. Note that we measure progression from the sag point and not from the start of travel. The leverage ratio curve is the starting point and most valuable asset available before testing. You can rebuild shocks while testing with the shock OEM, but prior to testing potential tunes are identified and prepared. And not all testing is done in presence of the shock OEM.

From the leverage ratio curve you can learn if your kinematics leverage ratio is kind of normal or not. If you have a fairly high leverage ratio more damping may be necessary. Damping forces depend on the displacement speed of the shock shaft. High leverage ratio numbers result in slow shaft speeds, and thus firmer damping tunes.

The leverage ratio curve also helps you to decide between air volume options. Positive and negative air volumes and their ratios affect the behavior of air springs and need to be specified. This means in most cases we can select a configuration of tokens that is installed in the shock. We believe that excessive use of tokens is not the way to go. Coil shocks and air shocks feel different, but their springs should have similar characteristics if used in the same frame. Making an air shock further progressive with many tokens is not necessary if the frame kinematics are progressive enough.

Testing includes a mix of riders that we know very well, including myself, riding the different options. We like to test on our home trails, at least in addition to more testing convenient bike park tracks, because we know our home tracks well. It helps a little with the difficult task of comparing stuff that might not be available at the same time. The testing can lead to a loop of modifying and continued testing until we are happy with the result.

We have some electronic measurement devices that help to evaluate certain aspects. They can be used to set sag exactly and and in a repeatable manner, notice how much travel is used etc. But we are far from letting these tools make the decisions. We are focused on providing a responsive feeling bike that let’s you enjoy each ride.

Summing up, before the first ride, both the shock maker and we have chats where we discuss ideas and learn about the new offers. The start for real life testing is an educated guess that both sides agree on, with us taking final responsibility for the testing and selection.

Custom Shock Tuning from the Suspension Manufacturer’s Perspective

FOX: Our FOX Factory OE Suspension Tuning Group works directly with frame engineers, designers, and product managers to realize the optimum suspension setups for our OE partner builds. The work of creating these setups can mean developing new bike specific damping forces, finding the sweet spot for existing product, and sometimes developing new product to meet the needs of desired end-user group. For those familiar with the Dialed YouTube series, OE tuning camps can resemble trackside at WC race events: meticulous lap testing, rider feedback, adjustments, tear-downs, rebuilds and doing it again.

FOX suspension is incredibly tunable, and the magic comes in finding the blend of meeting the frame dynamics, the intended riding category, and the expected user riding style. As suspension is an integral component in the design of the bicycle, we want the end-user experience to be smooth off the showroom floor. We also build our shocks and forks to have room for personal customization in the form of adjustable compression and rebound settings, volume spacers, and even additional valving and tune options down the line if a rider would benefit from changes.

Formula: So for the rear shock, this is how we do it:

Before the pandemic, and as we were starting with our very first MTB rear shock, we asked our customers (the frame manufacturers) to provide us with the leverage ratio and all the specifications, but also to give us some time with the frame in house at the Formula Factory to allow us to conduct internal testing before sending the shock back to the Bicycle Brand  for a test session.

During the pandemic, as it was impossible to move, we asked to the brands to send Leverage Ratio information and a complete test bike. Our engineers do the setup and testing before it is sent back to the brand for them to do tests of their own. Sometimes it works directly and sometimes they needed to play with the CTS on their own to adapt the setup as they want.

Nowadays, we have developed our base tune to be able the use the CTS technology as much as possible. The idea is (if the pandemic situation is under control in the EU) is to organize the test setup in the terrain always based on the leverage ratio of the frames for the basic setup and to play with the CTS to find the perfect match.

We know, there’s no such thing as a stupid question. But there are some questions you might not want to ask your local shop or riding buddies. AASQ is our weekly series where we get to the bottom of your questions – serious or otherwise. Hit the link at the bottom of the post to submit your own question.

The post AASQ #149: How do you custom tune a mountain bike rear shock? appeared first on Bikerumor.

We know, there’s no such thing as a stupid question. But there are some questions you might not want to ask your local shop or riding buddies. AASQ is our weekly series where we get to the bottom of your questions – serious or otherwise. Hit the link at the bottom of the post to submit your own question.

Welcome back to the Bikerumor Ask A Stupid Question series. This week we’re taking on a frequently used jargon term associated with full suspension mountain bike design: Brake Jack. You’ll see it used all over, from manufacturers’ press releases to mountain bike reviews, and of course, in the much-loved comments section of aforementioned bike reviews. But, what exactly is it, and does it bare any relevance on the more definable and, importantly, quantifiable anti-rise number? 

Answering your questions this week are a handful of full suspension mountain bike frame designers, all of whom will have considered anti-rise values, and possibly brake jack too, during the design of the suspension layout. Some of them have even gone so far as to add a floating brake arm to their bikes in an effort to control the braking characteristics. Your experts are as follows:

• Jeff Soncrant, Owner and Frame Designer at Eminent Cycles
• Nick Lester, a member of the R&D team at Commencal
• Christophe Benoit, Project Lead Engineer at Cycles Devinci
• Joe McEwan, Owner and Frame Designer at Starling Cycles

What is brake jack, and how is it different to anti-rise?

Eminent Cycles: It is the same thing, brake jack is a slang term for anti-rise.

Commencal: Brake jack is a braking system that uses the exhaust valves on trucks to create ancillary braking and prevent overloading the discs of the primary braking system. I don’t know whose idea it was to put this into bike jargon. It’s not a term that’s used in French either and there is no accurate translation for this expression in cycling. We give importance to the anti-rise and other parameters to study the braking behavior of our bikes.

Devinci: While they both refer to braking forces, they are not expressed in the same way. Brake jack is a resulting force in the suspension that comes from the caliper. In practice it is a force that gets transmitted to the shock but it is not the main force at play.

Anti-rise is expressed as a ratio of forces. The anti-rise method allows us to take into account the force of rider mass acceleration and the angle at which the load is transferred at the wheel. It is part of kinematic simulation and is considered with many other factors when positioning pivots (shock type, geometry, leverage ratios, axle path, pedaling characteristics).

Anti-rise assumes a lot of parameters such as the chain is completely slack when braking, specific fork position, rider position (for the Center of Gravity at which the acceleration is applied). In practice, we shift our weight depending on these variables.

Ultimately, the objective is the same for both: minimize the effect of caliper force and weight transfer under braking while keeping an active suspension. This is what we strive to do with our Split Pivot platform, whether it be in it’s “normal” form or with our new High-Pivot suspension platform.

Starling Cycles: In simple terms, anti-rise is how weight shift (from acceleration and deceleration) affects suspension.  Brake Jack is how braking forces affect suspension. All suspension designs have these effects in differing amounts.

Starling cycles suspension design has anti-rise as close to neutral through the full suspension stroke. Brake Jack is similar to other designs. Best advice with regards to braking, is do it in the right place. This will make you way better than any suspension design can, or claim to improve.

Does brake jack only occur when the rear wheel stops completely, as in when the caliper locks onto the rotor?

Eminent Cycles: Brake jack/anti-rise events occur when the brakes are applied with or without locking up the rear wheel. As soon as braking forces are applied to the rear wheel, during a braking event, the anti-rise situation analysis applies.

Devinci: Brake jack is a force and therefore it occurs as soon as the caliper hits the rotor (braking force is applied), even if the caliper is not locked.  

Commencal: I still don’t know what brake jack is! (There’s so much information about it, it’s very confusing).
However, it is certainly wise to study the braking behavior of a bike according to the braking torque applied. My advice is to pay maximum attention to the distribution of braking power, because for a large majority of riders, it is 80% rear brake that is used. This leads to imbalances in the chassis, issues with rider weight distribution, poor behavior of the rear suspension and therefore, quite often punctures or dents to the rims.

I saw Myriam Nicole ran a floating brake mount at some World Cup races this season. What does it actually do, and why don’t the other Commencal riders have one on their bike?

Commencal: Thibaut Daprela used the same system. Amaury, being unable to ride due to injury until the race, didn’t participate in the tests and we prefer for him to ride a bike that he knows perfectly for this important recovery back to racing.

The system objective was to improve the behavior of the bike on this rough, fast, and steep track (unfortunately, it’s impossible to say any more). So, we used this experience to collect data to utilize for future bike developments.

Got a question of your own? Click here to use the Ask A Stupid Question form to submit questions on any cycling-related topic of your choice, and we’ll get the experts to answer them for you!

The post AASQ #148: What is Brake Jack, and how does it differ from Anti-Rise? appeared first on Bikerumor.

We know, there’s no such thing as a stupid question. But there are some questions you might not want to ask your local shop or riding buddies. AASQ is our weekly series where we get to the bottom of your questions – serious or otherwise. Hit the link at the bottom of the post to submit your own question.

Welcome back to the Bikerumor Ask A Stupid Question series. This week we are challenge manufacturers of flat bar gravel bikes, asking if they are simply attempting to reinvent mountain bikes from the 90s, or if this “new” breed of bicycle warrants a category designation of its own. Your contributors are:

• Richard Lambert, Frame designer at Enigma Bicycle Works 
• Fergus Liam, US Marketing Manager at Ritchey
• Mehdi Farsi, co-founder of State Bicycle

What’s the difference between a modern flat bar gravel bike and a 90s Hardtail MTB? Are we not just reinventing the mountain bike here?

Enigma Bikes: The comparison between a flat bar gravel and MTB (and indeed a ‘hybrid’, dare I say it) is a valid one to make. Clearly there are similarities, but there are also a few key differences that make it a bike worthy of its own category.

Before I start, it’s worth pointing out that we produce this bike due to customer demand, we’re not trying to reinvent a rigid MTB with some bull**** marketing attached. We’ve already been making bikes like this as custom frames for years, and got to the stage where the numbers we were producing made it worthwhile to release a standard model in this style. We’re not trying to tell people what bars they should be riding, or saying that one bar is better than another, but just giving our customers all the options, there are many that simply prefer a flat bar!

Modern MTBs tend to be designed for much more extreme off road use than they were in the 90s, with low gearing, long travel suspension, slack geometry and wide tyres. All great for the typical trail riding you see these days, but if you’re using the bike partially on the road or ‘fire road’ type tracks then they can feel very unrewarding for the effort you’re putting in.

Back to the question, here are the key differences between our flat bar gravel bike and a MTB (90s or modern):

1) Gearing – Modern MTBs tend to fit a maximum 1x 34 tooth chainring or thereabouts. You would struggle to get a 1x 40 or 46/30 double on any MTB frame, which makes their road use limited. Our Escape will fit a 1 x 42 single or super compact double such as 48/31 GRX, whilst retaining clearance for a 700c x 50mm tyre (29″ x 2.0″ if you prefer). An older MTB would have fitted a triple with a 40 something tooth outer ring, but no one wants a triple any more, do they?

2) Forks – We believe the advantage of a gravel bike is that it’s simple and light compared to an MTB, and adding a suspension fork is perhaps a step too far towards MTB territory! Our frame is designed for our CSix ADV 395mm carbon gravel fork. This is very light (450g compared to 1226g for a Rock Shox Rudy XPLR) and looks much nicer than fitting a longer suspension corrected (480mm) rigid fork with a big gap above the tyre. Longer forks also make it difficult to fit a proper full length mudguard, and achieve a low stack height which is required on a small frame size.

3) Brakes – We don’t need to explain how much better modern hydraulic discs are compared to any rim or cable braking system. The 1990s can keep their canti brakes.

4) Geometry –  Many old school MTB frames tended to be very low at the front end, with a long, high rise stem required to bring the bars to a comfortable level, limiting the range of adjustment available. Our Escape is aimed at bike packing and commuting as much as having fun off road, so having geometry that’s a little more comfortable is a key feature.

We believe our Escape is a vast improvement on the 90s MTB. You can fit similar width tyres and have the choice of 650b or 700c rims. It has far better brakes, is lighter, more comfortable, and has a modern gear system with ample range for road and offroad. It’s aimed at people who are touring, bike packing, commuting, and of course riding gravel, but we hope there will also be a few riders who will take it round their local singletrack and come back smiling!

Ritchey: The first thing that comes to mind is wheel size and BB height. A 90s MTB was limited to 26” wheels and relatively high BB for clearance. Not to mention the limit of tire size! Today’s gravel and adventure bikes have the option of combining wheel size with greatly increased diameter when compared to a 90s MTB.

Back then, a mountain bike would typically have a 26” x 1.9-2.1” tire. Compare that to the clearances most gravel bikes can clear today: 700c x 48mm and a much different axle height. If you kept the BB drop the same on a gravel bike as 90s MTB, your center of gravity would be ridiculous. Gravel bikes don’t always encounter the same obstacles as MTBs did in the 90s, so you can run a lower BB and benefit from a lower center of gravity.

If we dive a bit further into geometry, we know we cannot just look at one element without it affecting other aspects of the frame design. Looking back those MTB frames of the 90s we see the reach being relatively short while long, squirrely-handling 140-160mm stems accommodated the fit of the rider; whereas, today’s gravel bikes handle best and are more stable with shorter 90-100mm stems while a longer reach on the frame opens up that space for the rider. Sure, headtube angles might be similar, but not without serious adjustments to the rest of the frame.

We aren’t reinventing the wheel with modern gravel bikes, rather we’re making more terrain more fun by learning from our MTB predecessors and by improving on what we’ve learned in the decades since.

State Bicycle: Let’s go Mountain Biking in the 90s forever! The difference is time. We love Flat bar gravel. The simplicity of 1x gearing, threadless headsets, 31.8mm stems, and modern seatpost sizes separate gravel bikes from mountain bikes of old. What about wide 650b gravel tires, thru-axles, and disc brakes that actually work? Or tubeless tires that let you run less than 50 PSI without carrying 4 spare tubes on your ride? We are digging Flat Bar Gravel.

Got a question of your own? Click here to use the Ask A Stupid Question form to submit questions on any cycling-related topic of your choice, and we’ll get the experts to answer them for you!

The post AASQ #147: Are flat bar gravel bikes a reinvention of the humble mountain bike? appeared first on Bikerumor.

We know, there’s no such thing as a stupid question. But there are some questions you might not want to ask your local shop or riding buddies. AASQ is our weekly series where we get to the bottom of your questions – serious or otherwise. Hit the link at the bottom of the post to submit your own question.

Welcome back to the Bikerumor Ask A Stupid Question series. We’ve got a bit of a strange one for you this week; we’re asking how cornering technique differs between Mountain Biking and MotoGP, and specifically, whether the counter-steering applied in MotoGP applies to Mountain Biking, too.

Of course, we’ve all seen the very Instagram-able “shralp” technique, some delicious examples of which I have collated at the foot of this article for your viewing pleasure. When the rear tire breaks traction, the rider counter-steers to exit the corner (turns the wheel in the direction opposite to that of the desired direction of travel) in order to prevent over-steer, and to prevent the front wheel from washing out too. But, what about corner initiation itself?

It’s been a little difficult to find appropriate contributors for this one. While both are performed on two-wheeled vehicles, there’s no getting around the fact that they are still very, very different sports. However, I’m satisfied we have reasonable representation from both sides here; we have a mountain bike suspension tuner, who also happens to distribute suspension for motocross bikes, a former MotoGP team manager who has latterly co-founded an eMTB brand, a small Italian Suspension Manufacturer with previous experience in developing suspension for motocross bikes, as well as a much larger, more well-known suspension manufacturer who make forks and shocks for both Mountain Bikes and MotoGP bikes. They are as follows:

• Terje Hansen, Racing Technician at Ohlins Suspension
• Pablo Fiorilli, Owner and Engineer at Bright Racing Shocks
• Nigel Reeve, Owner and Custom Damper Tuner at NSR Racing
• Livio Suppo, former Ducati Corse and Repsol Honda MotoGP Team Manager, co-founder of THOK

How does cornering technique differ between Mountain Biking and MotoGP?

Bright Racing Shocks: The fundamental differences between a motorcycle on the track in general and a mountain bike lie in two factors that must be considered together:

• In MTB, you are riding off-road; here, you are on a track that is almost always bumpy and constantly changing
  • On Track Motorbikes (like MotoGP) the track is always the same at each passage and is predictable in most of its aspects because it is unchanged. However, the trajectory chosen by the driver in the same corner can change

• In MTB, the relationship of the weight between the bike and the rider means that the rider’s mass is the one that must be supported
  • On Track Motorbikes (like MotoGP) the proportion of the mass between the rider and the motorcycle means that the latter is decisive in the choice of trajectories, for example

In other words, an MTB (like a downhill bike) can be moved at the last moment by the rider to force a particular passage. It is not possible to carry out this type of maneuver on the motorcycle.

When preparing a suspension fork for off-road riding, especially enduro or downhill mountain biking, the huge variability of the track must be taken into great consideration. It must be able to guarantee the rider a certain degree of handling. At BRIGHT, for example, we study in great detail the aspect of Sag management in order to create sensitive stresses even with a reduced static sag. This means that the rider is able to interpret the terrain and the trajectories with greater scope for improvisation, as they have a very reactive suspension fork at their disposal.

For off-road riding, precisely because of the variability of the track, the compromises to be made are very important to ensure great performance.

NSR Racing: Generally speaking, in theory, they are similar – weight the outside pedal/footpeg, apply counter-steer pressure to the inside hand grip, rotate the hips and position the head and torso low forwards, and towards the exit of the corner. In practice, because of the vast differences between the two sports you are not going to confuse the two positions with each other – vehicle weights, speeds, terrain, and corner radius will all combine to make sure you do not mistake your DH bike for your MotoGP bike.

THOK: The cornering technique is very different when talking Mountain Biking and MotoGP. The former is of course mostly performed off-road while the latter is a pure on-road on-asphalt activity. When cornering with a motorbike on a MotoGP or with a Bike on a MTB track you can use various techniques.

With the Mountain Bike you can corner using a banking or you can slide the bike on the gravel; in MotoGP you need to be super precise, you cannot ride banking against something. Also, the position on the [mountain] bike and on the motorbike is totally different, the handlebar is totally different, so let’s say that in both cases you are cornering on two wheels but it’s quite different when cornering with a Motorcycle and when with an MTB.

Ohlins: Two completely different styles of riding. A MotoGP rider is hard on the brakes before a corner, steer in, open throttle power slide or accelerate out of the corners. For MTB, since you don’t have the power from the engine it’s important to maintain speed through the whole corner which is tricky, not too fast or too slow going in because it’s your speed going into the corners that will decide the speed out of the corner.

In MotoGP, some of the riders counter-intuitively steer away from the direction they want to travel in. Does this ever happen when cornering a mountain bike, or even a regular road bike, at high speed?

NSR Racing: Counter steering is a product of steering geometry and is used to help initiate the lean of the bike into a turn. Since both motorcycles and bicycles use the same basic concept of steering geometry this technique exists on all motorcycles and bicycles.

The key difference is due to the weight difference between a 16 kg DH bike vs a 157kg MotoGP bike – the required amount of counter steer on a bicycle is barely noticeable because of the relative weight advantage the rider has over the bike, whereas the MotoGP bike has more mass in general, but also a huge amount more rotating mass (wheels, crankshaft etc.) which is rotating much faster. Therefore, the required counter steer input required to help initiate lean is more noticeable & deliberate.

THOK: If I understood correctly the question, I would say that yes, that’s true for the MotoGP but this is not a conscious movement that the rider is doing. It’s unconscious. So I would say it could be something typical of any rider on two wheels, either on a motorcycle and yes, on an MTB too.

Ohlins: No, in MotoGP they are sliding their bikes as a part of their cornering and therefore need to steer away.

Got a question of your own? Click here to use the Ask A Stupid Question form to submit questions on any cycling-related topic of your choice, and we’ll get the experts to answer them for you!

And now, some choice shralping and counter-steering for your viewing pleasure…

https://www.instagram.com/p/CTN1AH_Jd5z/?utm_source=ig_web_copy_link

The post AASQ #146: How does cornering technique differ between Mountain Biking and MotoGP? appeared first on Bikerumor.

We know, there’s no such thing as a stupid question. But there are some questions you might not want to ask your local shop or riding buddies. AASQ is our weekly series where we get to the bottom of your questions – serious or otherwise. Hit the link at the bottom of the post to submit your own question.

Welcome back to the Bikerumor Ask A Stupid Question Series. This week, we’re pivoting the conversation to bearings, specifically needle bearings, and their useful applications in bicycle componentry. You wanted to know what advantages, if any, needle bearings (aka roller bearings) offer over your regular cartridge bearing or plastic bush.

To answer your question in a comprehensive fashion, we’ve consulted a bunch of brands who utilize needle bearings at a number of different points on the mountain bike, from pedal axles, to frame pivots, to shock eyelets. Your expert contributors are as follows:

• Jamie Duncan, Design Engineer at PINND Pedals
• Matt Harvey, Co-Founder of Enduro Bearings
• Tripp Hurt (Partner/Engineer) and Craig Payne (Founder) of Hustle Bike Labs
• Chris Streeter, Owner of Real World Cycling (Enduro Fork Seals)

PINND: Why do our PINND CS2 pedals use needle bearings? We opted for a needle bearing for a few reasons. The 1st being that the main cause of pedal failure is due to internal seizure and this is usually down to the seal not working properly at the crank side. This is due to the bush wearing and allowing axial play on the axle which will mean the seal can’t work due to the errant movement.

No matter how fancy the bush is, at the end of the day, it’s plastic and therefore the weakest component in the pedal assembly. PINND designed this out and introduced a needle bearing in its place, which removes the play allowing the seal to work as it should. The sacrifice is a couple of millimetres in platform thickness and it costs a little more but we think the benefits are worth the sacrifice. No bearing will last forever, but they will outlive a plastic bush by a very, very long time!

Enduro Bearings: What is the advantage of a needle bearing over regular ball bearings or bushings? Well, needle bearings generally have a much higher static load rating than the same sized ball bearing. Needle bearings generally require higher tolerances of alignment, press fit and mating parts in order to work correctly. They cannot account for thrust loads as a single ball bearing can so sometimes you need mating thrust washers, bushings, or even ball bearings next to them to account for that.

They can work well on shock mounts where everything is in alignment without high axial loads (twisting, misalignment). They must be fitted quite tightly to avoid “knocking”. In our 15 year experience with supplying them for this duty, we have encountered very few problems with them. In Enduro Bearings design, we also supply them with separate seals on each side to keep them clean and retain the grease.

Do they hold up in wet and muddy trail conditions and how much reduced friction do they actually offer? If sealed properly, they will. There are integrated sealed needle bearings, however the needles in this case get shorter and the load rating comes down. The seals inside needle bearings are moderately effective, external seals on the sides work much better.

As for the statement relating to frame pivots… Multi linkage frame pivots generally have high axial loads (which is multi load directions, a side load is considered thrust loads, and Radial load is straight down perpendicular) where uneven side loads and twisting occur. Needle bearings need to work in an environment of good alignment so that the edge of the needle is not taking all of the load and “pinching”.

Max type ball bearings are very good at taking not only radial loads, but axial loads. This is in every direction. Ball bearings can account for the misalignment of 8 or 12 pivot points in many modern frames, where perfect tolerances due to welding or carbon layup are not possible.

Hustle Bike Labs: Needle bearings have larger bearing surfaces, known as the “needles”, so they are able to accommodate higher loads than a regular ball bearing and at a lower friction. Bushings are technically a type of bearing, but think of them more as a sleeve. They are oftentimes made of plastics and represent a cheaper option as they should theoretically fail more often than a steel bearing.

If you look at the historical uses in MTB: MRP used to have a kit to replace the bushings on the earlier models of Specialized FSR with needle bearings, Devinci used them in the early 2000s in the main pivot of their frames, and dirt bike companies have used needle bearings in their pivots due to the extremely high loads that exist in this application (high speeds and jumping).

However, I think a decision on “is it worth it”, should be more made upon the quality of the bearing than if it is needle versus ball bearing or even bushing. Friction ultimately will be dictated more by the quality of the bearing (the tolerance the machine is able to hit is really important here), materials it is made of (ceramic has a lower coefficient of friction than steel, and always choose high quality stainless steel), and oftentimes the other parts of the system (i.e. shielded versus sealed).

Real World Cycling: The main advantage of a needle bearing over a bushing is the decrease in friction, which is dramatic. In direct relation to the reduction of friction is the increased longevity of a needle bearing – especially in high rotation applications.

The main advantage of a needle bearing over a standard cartridge bearing is that greater load strength is provided in a much smaller package. Needle bearings can have up to 8 times the load-carrying capacity per given mass than other bearing types. If you have plenty of room to work with, this may not be an issue, but the weight difference is also significant.

Pedal axles are a perfect example of needing a strong and durable bearing in a compact space. Of course, proper engineering to get the right size and for proper sealing is essential, but in theory, for pedal applications, they make more sense than cartridge bearings. This doesn’t mean that doubling up smaller cartridge bearings or other innovative uses of standard cartridges can’t be successfully implemented for pedals (or a combination of bearing types used).

For upgrading standard rear shock eyelet bushings, I will let our many satisfied customers testify to the improved performance. One forum thread has over 34 pages of posts about our kits and is entitled “Real World Cycling Shock Needle Bearing Kit is Awesome.”

I will say that, where there is no rotation inside the shock eyelet, NO, it is not worth it. Often, at least one end of the shock remains in a fixed position relative to the frame. BUT, where there is rotation inside the eyelet, the improvement in responsiveness is quite remarkable, and a bargain for those obsessed with performance. We are happy to give honest assessments on a frame-by-frame basis as to whether or not your frame would benefit.

Do they hold up in wet and muddy trail conditions? Most hardened bearing steels are susceptible to corrosion. Different bearing materials, sealing options (internal to the bearing and external to the bearing) can be implemented by the engineer designing the component or frame. There is no inherent anti-corrosion benefit to one type of bearing over another independent of the actual bearing materials and seal designs. Speaking specifically about our Shock Needle Bearing Kits, the spacers include high quality seals, but frequent wet and muddy riding may require more frequent lubing of the bearing.

How much reduced friction do they actually offer? Compared to a bushing, in a bicycle frame pivot application (high load, low rotation) there is no comparison. Several manufacturers have made expensive transitions to various bushings for their frame pivots, including some elaborate angular contact bushing designs. With just a few exceptions, they have all come back to metal bearings of some sort. Regarding those exceptions, we get requests from customers for needle bearings to replace those places on the frame that have bushings.

One of the reasons we launched the Shock Needle Bearing Kit is because factory bushing systems were so bad that the shock hardware was wearing away parts of the frame (instead of rotating inside the shock eyelet).

Finally, with reference to frame pivots, needle bearings have been used in frame pivots. However, they are more difficult to properly integrate with the frame. Among other factors, manufacturers have to balance performance, price, and amount of labor to assemble when making frame design choices. Cartridge bearings come as a complete unit with outer race (or “ring”), inner race (or “ring”), ball bearings, and seals. The needle bearings have a separate axle (inner ring) that must also be made of the hardened bearing steel. The axle needs to fit properly inside the rollers, which is not easy when the bearing “cup” containing the rollers gets compressed in the frame. For mass production, cartridge bearings are easier to deal with.

Got a question of your own? Click here to use the Ask A Stupid Question form to submit questions on any cycling-related topic of your choice, and we’ll get the experts to answer them for you!

The post AASQ #145: Needle Bearing Tech with Pinnd, Enduro Bearings, Hustle & Real World Cycling appeared first on Bikerumor.

We know, there’s no such thing as a stupid question. But there are some questions you might not want to ask your local shop or riding buddies. AASQ is our weekly series where we get to the bottom of your questions – serious or otherwise. Hit the link at the bottom of the post to submit your own question.

Welcome back to the Bikerumor Ask A Stupid Question series. This week we’re taking a look at the environmental impact of drivetrain lubrication, challenging the big-names and the small producers alike on how they’re improving their chain lube formulas to make them less toxic and more environmentally friendly overall. Joining us this week are:

• • Borut Fonda, Scientist at absoluteBLACK
  • Josh Poertner, CEO of SILCA
  • Bryn Morgan, Product & Design Director, and co-founder of Peaty’s
  • Paul Sollenberger, Product Manager at CeramicSpeed
  • Jay Seiter, Product Management and Engineering at Pedro’s
  • R&D Director at MUC-OFF

What are bike chain lube manufacturers doing to make their products less toxic and more environmentally friendly? I’m aware there are a number of brands out there who make the “eco-friendliness” of their lube a major selling point, but how are the bigger brands looking to improve their existing products to prevent them from harming the environment?

SILCA: For the first 9 months after I bought SILCA, I ran the company out of my living room, including all of the small part assembly and packaging. As I had my whole family including my kids helping with the work, it became instantly obvious that we had to use the safest products possible. So, really from day one, we’ve only used lubricants, greases, and assembly compounds that are NSF approved as safe for food contact in all SILCA products.

When we came to develop our line of lubricants, it was only natural to work with the same food-safe suppliers, as well as tapping into technologies evolving within auto racing where we had access to some research and technology that was done in Europe as part of a project to ‘green’ engine lubricants used in F1 racing. The vision was not to develop just an environmentally friendly lube; those have been around forever and are generally regarded as being pretty bad. What we were after was developing the world’s best chain lube in terms of friction and wear using only environmentally sound base stocks and additives, and this F1 tech, gave us a pathway to do so in both dry and wet lubricants.

What we discovered was a lubricant technology vastly superior to PTFE and other PFAS related chemicals which was also deemed completely safe for human contact, water contact, and safe for aquatic life. If you look at independent testing, like that from Zero Friction Cycling you see that our technologies are number 1 or number 2 in every category when it comes to preventing chain wear, and we are also one of the most commonly referenced lubricants by our competitors when it comes to efficiency testing, so we can say without exaggeration that we have developed some of the best lubricant technologies currently on the market, which also happen to be completely environmentally friendly.

While we hope to build a strong business position in cycling lubricants, we also seek to create meaningful change in this industry, so in October 2021, we put out a statement to the industry disclosing all the ingredients and technologies used in our lubricants that also asked the industry to stop using PFAS ‘forever chemicals’ as well as toxic and flammable VOCs in cycling lubricants. We seek to educate dealers and consumers that some of the most toxic and dangerous lubricants on the market are also the slowest and most drivetrain damaging products (which is an additional environmental impact), but good marketing and low retail price points keep these products on shelves.

My hope is that by having these discussions and being as open and transparent as possible, we can inspire other manufacturers to move away from these dangerous and toxic chemicals and toward safer (and better performing) ingredients. Sadly, the biggest hurdle here is likely cost; it costs just pennies to put PTFE or similar PFAS particles into a toxic VOC like Heptane, in many cases these lubes are only 5-10% lubricant in a volatile carrier and therefore are extremely cheap to produce and can be sold at high margins at very low prices.

This is just not the case with some of these modern high-tech, environmentally-safe base oils, and additives, which is why it is so important to educate consumers and retailers to not just the environmental benefits, but also the drivetrain life improvements which can make these superior lubricating technologies much less expensive over the long run if you cost things out with a ‘total cost of ownership’ type model. While the superior lubricant may be $10-15 more expensive upfront, it may double or triple the life of your $60 chain and in turn double or triple the life of your $300 cassette, which not only saves money but has its own environmental story by reducing the need to manufacture replacement parts, dispose of the worn-out parts, etc.

Ceramic Speed: CeramicSpeed is a proudly Danish company, with environmentally conscious choices rooted as cultural norms and present within all levels of the company. When CeramicSpeed first approached the chain lubrication market in 2016-2017, we were laser-focused on creating the most efficient chain product possible, bar-none. While we achieved this target with our first UFO Drip formula, we immediately challenged ourselves to achieve an eco-friendly formula that still achieved our efficiency targets. From bottling and shipping to storage and user-friendliness, we valued the positive impact an eco-friendly, non-toxic, and biodegradable formula would deliver.

During this period, we also addressed our chain optimization operations, and discontinued the use of hydrocarbon solvents for chain cleaning, introducing our own in-house chain cleaner that was non-toxic and eco-friendly. This later was released as a consumer product, known as our UFO Clean Drivetrain. Today, non-toxic and biodegradable are key criteria for our chain products and cleaners, both for our own production uses, as well as consumer products.

We believe that it takes solidarity to implement lasting positive changes, and we approach our entire product range with longevity as an important piece of our product value proposition. With serviceable bearings, rather than disposable parts, and lifetime warranty support on our coated bearings, our aim is to offer products that enhance your riding while also reducing the need to replace more parts due to wear.

absoluteBLACK: There are a few factors that should be considered regarding the impact of lube on the environment.

The main ingredients of the GRAPHENlube are water, wax, and a small amount of graphene which binds to the wax. There is no safer carrier in the chain lubricant than water and no better “chain link separator” than wax. Since wax is not really a “lubricant” on its own, we use graphene to achieve the desired lubricity. If you care about the environment, you should use lubricants that contain water as a carrier.

We also don’t offer a plethora of lube types for “different conditions” meaning that we minimize the generated amount of plastic waste. We have only two types, and both are based on wax that is nontoxic. We don’t use Teflon powder nor volatile solvents commonly seen in “dry lubes” as this is an environmentally unfriendly option (in our opinion).

Toxicity is one aspect, but the quantity of lube you are expelling into the environment during cycling is equally important. The more lube you need to use the more you pollute and more needs to be produced increasing plastic waste. We developed the longest-lasting lube on the market, meaning that you use very little for very long. That alone minimizes the waste and the ecological impact. One bottle can last up to 16,000 km (9950 miles) of use with very low friction, which also means that you are greatly extending the life of your drivetrain components (like chain and cassette), minimizing the number of parts that end up in a landfill over time.

A chain lubricated with GRAPHENlube does not need to be repeatedly cleaned with any sort of chemical degreasers. All you need to do to get a clean drivetrain is a clean cloth and boiling/hot water, which melts the wax.

Minimizing toxicity alone is important. However, what really matters is the full picture. What evaporates from the lube during the application, how much lube you need to use per km, how many plastic bottles this generates, what chemicals you will have to use to clean dirty lube off the chain before reapplication, how easy it is for the lube to drip into the environment, and lastly, how often you will need to replace your drivetrain components (generating more product waste and packaging).

Peaty’s: The balance – as ever – is between performance/durability and eco-friendliness.

A good chain lube will keep your drivetrain running smooth and clean for longer periods of time without gunking up into an immovable paste. Wet-specific lubes also need, more than any other lube, to stop flash rust (after water is left on a chain for long periods of time) and prevent your chain from premature death.

Ultimate eco-friendly/plant-based/renewable oil alternatives do not provide this level of performance without the addition of further things like water-proofing agents, high-pressure additives, and rust inhibitors – all of which need manufacturing and transporting from all over the world, so are not as eco-friendly. It’s of course possible to run a chain on olive oil, but the consumer would need to apply the lube far more frequently and manually, and thoroughly dry off their chain after every wash or ride to prevent rust.

Take our LinkLube Dry for example. It’s the most eco lube in our range, made up of a water-based wax emulsion that uses completely natural and renewable waxes. The only human-made additive in there is a fungal inhibitor, but this is only to stop bacteria growing in there while sitting in storage (oxygen + water + food (wax) + warm environment = fungal growth).

This lube is totally awesome in dry, dusty conditions – doesn’t attract dust and lasts ages – but naturally doesn’t last as long in wet conditions. Now if we sold this as a wet lube we’d probably be scored 2 stars in a magazine review – and people wouldn’t buy it – but it does work, it just requires more frequent application in wet conditions and more hands-on bike care from the consumer.

All of our lubes (even our wet lube) are really easy to wash off which again is really important. If a lube has crazy waterproofing additives to make it last forever in wet conditions then it’s very likely to gunk up and requires more savage, non-eco-friendly degreasers to remove it… A super eco/non-toxic lube that needs a super toxic degreaser to remove would be a bit daft.

For us, more than saving a watt or two at the expense of the environment, ultimately a chain lube needs to make maintaining your whole drivetrain incredibly easy, and make it last for many miles longer. If you take into account everything that goes into the making of drivetrain components (extraction/processing of raw materials > transport to manufacturer > parts manufacture > packaging > parts shipping > distribution > logistics) then maintaining existing components rather than wearing them out quickly and purchasing again new is ultimately the greater good for the environment… That’s even more important when you take into account the shortage of drivetrain components these days!

Our wet- and dry-specific lubes are completely readily biodegradable whilst providing all of the necessary durability and protection, so we’re doing what we can, but nobody can hide from the fact these products still need manufacturing, packaging, and shipping to reach a consumer.

On the packaging front, we always try to make our bottles transparent, with minimal single-color printing to enable easier recycling once the chain lube has been used up. Did you know most black bottles can’t be recycled?

Both of our LinkLube All-Weather and Premium All-Weather chain lubes could be classed as readily biodegradable by the technical standards however, morally, we wouldn’t want to advertise them like this as there is a small percentage of non-biodegradable ingredients in there. Unfortunately, these ingredients are crucial for the all-weather performance those lubes are loved for (we tried removing them but they just didn’t work as well), but we’re continually searching for alternatives to also make those lubes perform just as well but with 100% readily biodegradable ingredients.

Pedro’s: Pedro’s bike care has led the way since the early 90s with user safety and environmentally-friendly formulas being central to all our offerings. Our biodegradable Oranj Peelz degreaser, first offered in 1994, contains less than 30% solvent content; far less than our “bigger brand” competitors even today who often rely on solvent content as high as 75-95% in their “citrus” degreasers (only 0.1-1% of which is actual citrus solvent).

Not content with that, in 2012 we started working on degreasers that were completely free of chemical solvents. The resulting products, Degreaser 13 and Pig Juice were introduced in 2015. The process was not without challenges. In the chemical world, not all the players play by the standards that we do at Pedro’s.

When we found out a key ingredient could potentially contain trace amounts (contaminants) of a chemical listed on California’s Prop 65 list, we hit the brakes and found a solution we knew would be safe for our customers. It was worth it. Degreaser 13 is an incredible solvent-free advanced-chemistry surfactant degreaser designed for use with water instead of chemical solvents. It is now our highest performing and most versatile degreaser. It is biodegradable, non-hazardous, non-flammable, zero V.O.C., plant-based, and safe to use on any material.

With a higher viscosity and concentrated power, it can be applied very efficiently with almost no dripping/waste, and less is needed. Degreaser 13 is also ideal for use in ultrasonic parts cleaners where it can be diluted with up to 30 parts water. Pig Juice is a low viscosity solvent-free advanced-chemistry surfactant degreaser featuring the same base chemistry found in Degreaser 13. It features less raw power but requires less rinsing and flows nicely into tight spaces. Pig Juice was formulated for use in the Chain Pig chain cleaner which uses mechanical action to reduce how much degreaser is needed to clean a chain. When done regularly, only 1oz of Pig Juice is needed per cleaning. Pig Juice is biodegradable, non-hazardous, non-flammable, zero V.O.C., plant-based, safe to use on any material, fragrance-free, and dye-free.

For cleaners, our Bike Lust polish, the original bike polish, is fully biodegradable and non-toxic and has been keeping bikes clean, protected, and looking like new since the early 90s. It is a staple in bike shops used daily for keeping showroom and customer bikes looking their best. Bike Lust’s slippery coating helps to repel dirt and grime while you ride which makes future cleaning quicker and easier. It is also fantastic for water-less light-duty cleaning.

Bike Lust’s biodegradable formula cleans, polishes, and protects in one step, going on wet, quickly cleaning light dirt and grime as it polishes, and then dries to a beautiful protective coating. More recently introduced in 2007, and further improved in 2015, our Green Fizz bike wash safely, naturally, & effectively removes tough dirt & grime from the whole bike. The pre-activated formula uses advanced plant-derived surfactants and incredible foaming action to reach surfaces and loosen dirt allowing it to be easily wiped or rinsed away leaving your bike looking like new.

Green Fizz is free of harsh chemicals, gentle enough to use on any material, biodegradable, phosphate-free, solvent-free, plant-derived, and zero-VOC. We also offer Green Fizz as a 16X concentrate. One bottle of 16X Concentrate will make SIXTEEN 16oz bottles of Green Fizz bike wash! So what is the big deal? It’s all about reusing that perfectly good spray bottle you already own, reducing energy use, and saving money! Green Fizz 16X Concentrate is incredible value and allows you to custom-tune cleaning power; boost strength for tough jobs or dilute further for even more economy.

In terms of lubes, Pedro’s started pushing the needle in 2007 and 2008 introducing fully non-toxic and biodegradable Chain Lube, Go!, and Ice Wax 2.0 lubes which were way ahead of the curve. Fast forward to 2015 and after many years working on our next generation of lubes, we launched Enduro, X Dry, and Slick Wax. These lubes feature our CleanTech Chemistry which is a proprietary approach to chain lubrication chemistry developed by Pedro’s to achieve new standards of performance using ingredients that are safe for mechanics and riders.

Chain lubes commonly feature toxic ingredients that are unsafe for the user and harm the environment. With CleanTech Chemistry, there are no compromises. CleanTech Chemistry lubes share a similar base chemistry but each employs a unique lubricant package designed to optimize the chain surface coating characteristics and maximize performance for the intended riding conditions while keeping the drivetrain exceptionally clean. These lubes use a plant-based ethanol carrier to deliver the lube package where it is needed and are biodegradable, use safe non-toxic ingredients including only plant-based oils and waxes, and importantly still offer incredible race-proven performance.

Looking to the future, we continue much as we did back in the 90s with a focus on user safety and environmentally-friendly formulas. We will continue to look for ways to make our formulas even safer, continue to reduce how much of our product is needed to get the job done and to find new ways to reduce packaging.

How could we make our formulas ever safer? As safe as our current formulas are, we continue to strive to do even better while always balancing these goals with performance. What good is a safe product if it doesn’t work? For instance, some of the ingredients in Degreaser 13 can cause irritation to skin and eyes as is cautioned about on the label. You’ll find the same cautions on safe eco-friendly laundry detergent. Still, we would love to advance our degreasing chemistry to the point where these cautions are no longer needed but so far the balance with performance isn’t there yet.

MUC-OFF: By far and away the biggest change for us in terms of making our lubes less toxic and more environmentally friendly has been the removal of PTFEs from our entire lube range (and cleaning/protectant ranges). PTFEs can cause serious harm to wildlife when they drain into water sources, so developing alternatives to this was a big focus for us.

In terms of wider focus on environmental considerations where our lube development is concerned, our joint research project with the Laboratory of the Government Chemist (LGC) and National Physical Laboratory (NPL) represents an interesting case in point. While the time constraints of a three-month collaboration confined us to the performance aspects of lubricant development, many of the learnings that emerged from the laboratories of LGC and NPL have advanced our understanding of readily biodegradable formulas.

Our Project Landa Story:

Back in 2020 we developed an ultra-low-friction lubricant for Mikel Landa; although the sole priority was to create the most efficient lubricant possible (one with the lowest possible coefficient of friction) rather than to formulate a high-performance solution from biodegradable components, the story led to some very interesting findings, which would change the shape of our lube development process thereafter.

Two strategic considerations underpin the success of the Project Landa lubricant as a biodegradable formula. The first was to create the lubricant from scratch and to benchmark each individual component; a huge undertaking that led to more than 200 hours of screening, but which provided ultimate control over its chemical composition. The second was to follow a conventional formulation process, blending base oils and additives, rather than using nanoparticles.

While motivated by time constraints (creating a formula in which the behaviour of certain nanoparticles is stabilized can be very time-consuming), it allowed us to consider a range of base oils and additives, including those classed as biodegradable, that formed part of the final formula.

The base oil used in the Project Landa lubricant is an ester, rather than a mineral oil or even a Group Five synthetic oil (polyalphaolefin), both comprised of hydrocarbon chains, whether by refinement or synthesis. While esters are also synthesized, the presence of oxygen in their branched structure, in addition to hydrogen and carbon, allows them to degrade by natural absorption of the oxygen molecules.

Esters offer the advantage of high viscosity too, allowing the Project Landa lubricant to reduce component wear, as well as to provide supreme efficiency thanks to its ultra-low-friction properties. Both qualities result from the absorption of oxygen molecules on the lubricant’s surface. While oxidization can compromise an ester’s stability, typically this occurs only at very high temperatures, such as those inside a car engine, making it a remote contingency for a cycling time-trial held in September at a ski station in northern France.

The formula’s success can be measured in large part by Landa’s performance on stage 20. While the Basque rider is regarded as one of the world’s best climbers, he is not considered a time-trial specialist. Even so, his performance against the clock, and notably on the brutal finishing ramp to La Planche des Belles Filles, was enough to move him up the final standings. He rolled into Paris the following day in fourth place overall to claim his joint highest finish in cycling’s greatest race. More details on this and much more can be found on our Performance Hub.

Ludicrous AF:

We have carried this experience through to our latest lubricant invention: Ludicrous AF. Being readily biodegradable was once again at the top of the list of requirements. Dubbed ‘The World’s Fastest Race Lube’ Ludicrous AF takes drivetrain performance to a whole new level. It took our Research and Development Team over three years to create the one-of-a-kind lubricant that was developed in secret alongside pro-cycling powerhouses INEOS Grenadiers and EF Education-NIPPO.

The lube was perfected throughout the 2020 Grand Tour season, with multiple podiums and an overall win at the Giro d’Italia 2020 and 2021 to cement it as the lube to beat for any brand. While it is the fastest lube around, that is not all it offers. Crucially, the formula is non-toxic, offering piece of mind for any rider using it. In wet conditions or when a bike is being cleaned, naturally, lube will be washed away – thanks to its readily biodegradable ingredients, this can happen without impacting the environment.

Ludicrous AF will also prolong the life of a rider’s chain and even bring it back to life. The lubricant continues to improve with chain run-in due to continued surface improvement at a molecular level, so riders save on environmental wastage by using their existing chain again and again, whilst maintaining the same incredible level of performance.

Beyond Lube:

In 2020, we launched Project Green, an ambitious, wide-ranging, and ongoing initiative led by a bold commitment to eliminate more than 200 tonnes of plastic usage by 2023 – A target that we’re on track to achieving, with the current total sitting at well over 100 tonnes so far.

Our mission has always been continuous improvement for everything we create, we love the planet we ride on and are driven to protect it for futures riders! We’ve always believed in making our products as sustainable and kind to the planet as possible with an ongoing commitment to always improve. We created Project Green as a focus which will never be finished and a commitment to deliver a multitude of improvements across our business. A simple focus to protect the playground we ride in.

Got a question of your own? Click here to use the Ask A Stupid Question form to submit questions on any cycling-related topic of your choice, and we’ll get the experts to answer them for you!

The post AASQ #144: How are chain lube manufacturers making their lubes less toxic? appeared first on Bikerumor.

We know, there’s no such thing as a stupid question. But there are some questions you might not want to ask your local shop or riding buddies. AASQ is our weekly series where we get to the bottom of your questions – serious or otherwise. Hit the link at the bottom of the post to submit your own question.

Welcome back to the Bikerumor Ask A Stupid Question series. This week, we’re tacking gravel bike geometry, and how wheelbase, stem length, and fork offset contribute to handling properties like stability and agility. Joining us this week are the following experts:

• Max Koenen, Gravel Bike Engineer at Scott
• Aaron Abrams, Product Director at Marin Bikes
• Ritchey; a collaborative effort from the team
• Dave Weagle, Frame Designer at Evil Bikes

Would a Gravel Bike with a short wheelbase, low trail but long stem behave similarly to a bike with a long wheelbase, high trail, and short stem? Does the length of the wheelbase and/or trail have the same impact on stability as the length of the stem? If not, which is more important for stability and how would I feel this difference during a ride? 

Marin Bikes: In our experience, a longer wheelbase is always going to feel more stable than a shorter wheelbase, but head tube angle and stem length will still very much affect the steering feel. The two cases given (short wheelbase, low trail, long stem vs. long wheelbase, high trail, short stem) are exactly the differences between what we used to see on MTBs all the way to the 2010s, and what we’re seeing on MTBs now.

The benefits of the modern geometry are undeniable with handling, comfort, and safety on the bike at most speeds in most conditions, and this is the same on a gravel bike, albeit with less “extreme” geometry numbers than what’s being pushed in the Enduro MTB category.

To summarize the feeling of the bike with a longer wheelbase, more slack head tube, and shorter stem (preferably with a wider handlebar too!), there is a less twitchy, more planted feel to the front end. The bike is still easy to steer, but the feeling that the front end would require so much effort and focus to keep pointed in the desired direction is pushed aside and allows the rider to focus more on what’s coming further down the path. That predictability means the rider can ride faster and still have the feeling of having more time to react to obstacles, and also feel more comfortable keeping the bike in the desired path when they’re tired.

Ritchey: In answer to your question, “Would a Gravel Bike with a short wheelbase, low trail but long stem behave similarly to a bike with a long wheelbase, high trail, and short stem?”, our answer is… These are two things that don’t really have anything to do with each other. So, no, these two bikes would not behave the same. The ride characteristics of longer chainstays cannot be replicated with a longer stem or even a low trail. 

The first sounds like a cross bike. Most drop bar bikes with shorter wheelbases (like the Ritchey Road Logic and Swiss Cross) are designed with an optimal range of stem length in mind, usually 90-110mm. These bikes are meant to be agile and quick handling in tight, race-like scenarios, whereas gravel and off-road specific bikes, like the Ritchey Outback and Ascent are designed for a shorter stem, usually 70-90mm, and are meant for long, smooth travel over rough surfaces. Stem length and trail have to do with handling more than the ride quality of a longer chainstay.

In answer to your question, “Does the length of the wheelbase and/or trail have the same impact on stability as the length of the stem?”, again, the answer is, No. The stability that comes with longer chainstays is built into the DNA of the frame. The way it feels going into, and coming out of, a turn would be different. A longer stem would slow down the reaction of the front of the bike, yes, but the way the whole bike stays stable in straight lines and in turns is defined by its wheelbase and chainstay length.

Which is more important for stability and how would I feel this difference during a ride? Well, a bike is more stable and reliable because of its built-in geometry. A longer or shorter stem will certainly dial in a fit, thereby adding some stability, but a longer stem is no match for a well-designed frame. There are elements of the bike that are individualized, such as stem length, trail, chainstay length, seat tube angle, etc. that are important to consider…but it’s most important to consider all of this as a whole.

This all makes the bike complete – how and what it was designed for and with what components that inform the ride quality. It’s silly to say only the chainstay makes a difference with the handling when it’s inherently tied into the trail of the front end, the length of the head tube, the length of the top tube, and even the choice of tires. This is why when we look at warranties, we want to see the whole bike and how it was used because that informs how something failed. Think of a bicycle as a spider web: you cannot tug on one string and not shake the entire structure.

Scott: In answer to your question, “Would a Gravel Bike with a short wheelbase, low trail but long stem behave similarly to a bike with a long wheelbase, high trail, and short stem?”, my answer is, No. This is because the wheelbase and trail influence the agility and steering characteristics of the bike while the stem length (and bar width) influence the translation of the rider’s input to the rotation of the front wheel.

If you translate this to cars it might become more obvious: A long wheelbase and a small steering angle of the front wheels results in a very high turning radius of the vehicle. This is the characteristic of the chassis that you can’t compensate for by simply increasing the transmission ratio of your steering gearbox.

A frame geometry with a long trail and a long wheelbase will result in a rather sluggishly handling frame. Combining this with a shorter stem will only result in a harder-to-steer bike. As the leverage between the rider’s hands and the steering axis decreases, one needs to produce a much higher force to turn the bar.

In answer to the question, “Does the length of the wheelbase and/or trail have the same impact on stability as the length of the stem?”, again, my answer is, No. This is because the wheelbase and trail influence the agility/stability of the bike’s chassis while the length of the stem influences the leverage of the rider’s steering movements and so it acts as a transmission.

Imagine riding a bike with no hands just by leaning your body weight in the direction you want to go. A too stable frame geometry with a long wheelbase and trail will be harder to steer around corners while a geometry with a short wheelbase and short trail will be nervous and difficult to ride in a straight line. The stem length has almost zero influence on the steering characteristics once you take your hands off the bar.

Finally, in answer to the final question, “Which is more important for stability and how would I feel this difference during a ride?”, I would suggest the following.

The frame geometry is the most critical factor for the stability of a bike. You will feel this during your ride when you take your hands off the bar or when you ride in squally crosswinds and at higher speeds. On a bike with high directional stability, it will be easier to hold a straight line.

But, this stability comes to the detriment of agility. If a bike is too stable it will feel sluggish and hard to lean into corners. High-speed switchbacks or tight roundabouts may be challenging as well as quick directional changes. So, choosing the right geometry for a bike is always a trade-off between agility and stability.

Evil Bikes: For sure the combination of a longer wheelbase and high trail will feel radically different to a bike with a shorter wheelbase and low trail. The question of whether either wheelbase vs. stem length will impact stability more than the other is a pretty broad one and I think needs to be really considered situationally to start to get a handle on it. Breaking down the parts, a longer trail will require more steering torque to initiate and adjust cornering by steering; this adds to a feeling of stability as the forces at the wheel will impart more of a caster effect with more trail than less.

There are also some nuances to consider when hitting obstacles, wherewith more trail, a larger obstacle can be ridden over before the steering system can transition to a zero trail or negative trail state. Furthermore, fork offset can contribute to “flop factor” (also known as axle drop) where greater values can be beneficial for helping the rider balance at very slow speeds (track standing) and sometimes detrimental at higher speed steady-state cornering when the front wheel is sliding.

To get a grip on how wheelbases and stems factor in, it’s important to nail down a couple of facts. 1) Wheelbases are a combination of aligned chainstay length, aligned front center length, and BB drop. 2) One of the most if not the most critical component of “feeling” stability is center of gravity location (CG). 3) Saddle location and grip location will clearly define CG location when seated and drive body positioning when standing, cornering, or attempting more dynamic ride actions such as J-hopping, manualing, jumping, etc.

So, with that, let’s consider two extremes; climbing a steep grade and descending a steep grade. 4) Every person is sized differently, not all 50th percentile people have the same leg lengths, arm lengths, torso lengths, etc., so bike fit and therefore CG location are highly individual and not cookie-cutter in any way.

Consider two bikes with equal wheelbases, BB drop, and saddle fore-aft position (I disregard seat tube angle as a useful measurement and refuse to use it). The first has a longer chainstay, shorter front center, and longer stem. The second bike has a shorter chainstay, longer front center, and shorter stem. This first bike will carry more weight on its front wheel than the second bike, its CG is shifted forwards in relation to the contact patches. This will allow the rider on the first bike to climb steeper grades while seated without looping out, but when the riding situation changes to descending, now the bike with the more rearward weight distribution will allow the rider to center their weight between the wheels more easily. That right there is the reason why more rearward CG locations can impart a feeling of stability to riders in more aggressive riding situations.

In the end, not every rider is built the same, rides the same, comes from the same riding background, or likes the same thing, and that’s cool. From my standpoint with the Chamois Hagar, I wanted to build a gravel bike for riders coming from the aggressive side of mountain biking. I pitched this bike to several of my partners and ultimately Evil took a flyer on it. Yes, when it debuted it was a serious outlier, and perhaps a bit ahead of its time, but for riders who want to push the limits on the skills side of gravel riding, it’s an impressive tool largely due to its combination of more rearward CG location and mountain bike level of mechanical trail. The future will tell us if gravel biking will head in this direction, so far it seems that way.

Got a question of your own? Click here to use the Ask A Stupid Question form to submit questions on any cycling-related topic of your choice, and we’ll get the experts to answer them for you!

The post AASQ #143: Gravel Bike Geo – How handling relates to wheelbase, stem length and fork offset appeared first on Bikerumor.

We know, there’s no such thing as a stupid question. But there are some questions you might not want to ask your local shop or riding buddies. AASQ is our weekly series where we get to the bottom of your questions – serious or otherwise. Hit the link at the bottom of the post to submit your own question.

We’re keeping it short and sweet this week, joined by Rene Krattinger, MTB Product Manager at Scott Sports to discuss why more and more of the big frame manufacturers are moving their Boost (148mm x 12mm) spacing mountain bikes from the standard 52mm chainline to a 55mm chainline.

So, what’s up with 55mm chainlines on 148mm bikes? The industry settled on 52mm a few years back. Now Shimano says 55mm is the way to go and Trek’s all-in with the revamped Top Fuel (55mm chainline not just with Shimano cranks, but also SRAM and E13). I just can’t believe 55mm in the lowest gears can be good for a chain.

Rene Krattinger, Scott: 55mm chainlines present no problem at all for the chain, cassette, and chainrings. This change has been tested on the world cup circuit for almost two years now. With leading groupset manufacturers stating that the increase in width is the way forward, we are confident that their products are being designed to work perfectly in this scenario.

From a frame engineering point of view, even tiny increases in clearance in this critical area can substantially help with frame strength, stiffness, and/or tire clearance. We are always fighting for space in the area around the widest point of the tire and the chainring. To move to 55mm, therefore, presents a good opportunity for us to progress the performance of our frames.

How does chainline affect Q-Factor, and is this something frame manufacturers consider?

Rene Krattinger, Scott: Q-factor has increased a couple of mm, but in the near future new crank development aims to adjust the Q-factor for these changes in chainline width, therefore moving back to the narrower measurements. With these changes coming through, a 55mm chainline will therefore establish itself as the standard in the future with any potential downsides having been corrected for.

Editor’s Note:

We also sent the reader’s question out to Travis Ott, the Marketing Manager at Trek Bikes. He said “it’s really a convention dictated by the drivetrain manufacturers. Anytime the drivetrain manufacturers can give us a couple more mm in that critical area for tire clearance and pivot junctions and bolstering chainstays, we’ll take it every time.”.

Got a question of your own? Click here to use the Ask A Stupid Question form to submit questions on any cycling-related topic of your choice, and we’ll get the experts to answer them for you!

The post AASQ #142: Why are brands moving Boost frames from 52mm to 55mm chainlines? appeared first on Bikerumor.

We know, there’s no such thing as a stupid question. But there are some questions you might not want to ask your local shop or riding buddies. AASQ is our weekly series where we get to the bottom of your questions – serious or otherwise. Hit the link at the bottom of the post to submit your own question.

Welcome back to the Bikerumor Ask A Stupid Question series. This week we delve into aerodynamics, taking a look at which bike components offer the best bang-for-buck drag reduction to improve the aerodynamics of a regular road racing bike. Where is your money best spent? Is it on the wheels, at the handlebar, the fork, or is it actually better spent on improving the aerodynamics of you, the rider? Joining us this week are:

• Jean-Paul Ballard, CEO and Co-Founder of Swiss Side 
• Gillian Jakob, Brand Manager at Cervelo
• Scott Stroot, Retül Fit Guru at Roval Components

Finally, we also have Sam Pendred joining us from Hope Technology, designer of the Hope HB.TT, a road-worthy version of the Olympic Track Bike built for the British Cycling Team that competed in Tokyo. Though he can’t comment specifically on what gains different components offer, he is able to give an unusual insight into how aerodynamics was considered in the design of the HB.TT. 

Which bike parts offer the best opportunity for improving the aerodynamics of a bike? In terms of Watts saved, where is my money best spent in terms of upgrades? I’ve a standard road bike that I’d like to use for time trial racing.

Swiss Side: Even as a wheel brand, we’d be lying if we said that wheels offer the biggest aero gains. They are super important and high up the list but not at the very top. To answer this question, we need to look at the total bike and rider system and which parts of this system contribute the most drag. In road cycling, the rider is around 75% of the total aero drag, so this is our first point of call.

The rider position makes the biggest difference and costs nothing. The difference between the ‘cafe position’ (top bars, hands in the middle, straight arms) and an aero position with arms bent with hands flat on the hoods, is around 40W at 35km/h (85W at 45km/h). So, the biggest bang for buck is your yoga class to build core strength to ride lower positions for longer.

The next biggest influencer is rider apparel. A snug fitting one-piece aero suit can bring 14W at 35km/h (30W at 45km/h). Add winter gear and these numbers double again. So, being conscious of what apparel you choose is very important.

Next up are indeed the wheels. A good set of aero wheels deliver in the order of 7W at 35km/h (15W at 45km/h) over a normal set of stock low profile aluminum wheels. And, this benefit increases significantly when there is wind about due to the “sailing effect”. A good front wheel can actually generate thrust (negative) drag if the wind is right.

Helmets also provide plenty of potential in road cycling (and time trial). Between a good aero-road helmet and a simple heavily ventilated non-aero helmet, we have measured differences up to 5W at 35km/h (10W at 45km/h).

Of course, last but not least is the complete bike frame. This is however a big investment and not really ’tuning’. The difference between a standard frame and a top level aero-road bike frame can be up to 20W at 35km/h (43W at 45km/h). This is not including the aero wheels.

Cervelo: The single most effective upgrade is body position. Purchase a set of clip-on aero bars if you haven’t already (these don’t have to be expensive, round alloy ones will do just fine).

If you’ve not had a professional fit (either in person or with a number of great apps) it’s worth the investment. Not only will this ensure you’re physically in the best position for your body shape, but also that you’re able to comfortably hold that position, which is arguably more important.

Another low hanging fruit is clothing; you don’t need to go out and find the most expensive skin suit available, just ensure that everything is tight fitting once you’re in the correct position. If it’s a flat course and you’re comfortable with your power output, remove the front derailleur and run the bike 1x.

If it’s a longer course and you need hydration, look at bottles and cages that fit between the arms (clip on aero bar bottle cage) or behind the seat. And finally, tyres and wheels. This will take some serious investment but it’s a fundamentally important next step.

Wheel aerodynamics can easily take up its own article but, in short, look for the right balance between stability, weight and aero performance; narrow and deep for the rear wheel, wide and shallower for the front (if your frame can accommodate it). Ensure that the tyre you choose (brand and width) matches the wheel profile.

Roval: Within Roval’s arsenal of equipment, the rider looking for the best bang for his/her buck when it comes to aero gains on a road bike should think about their leading edge. Obviously, it’s no secret that wheels are a huge aero upgrade.

Common knowledge has been deeper is faster for a TT, but with our Rapide wheel we focused not only on a super aero 51mm deep front wheel, but ensuring that speed came with the stability necessary to use it – 25% more stable in a crosswind than our CLX50.

We also recommend our Roval Rapide bar, offering a 20 second saving over a round bar, with aero details like a recessed step to ensure your bar wrap is flush with the tops and internal cable routing. Another key bar stat to keep in mind when looking for aero gains is width. I’m sure you’ve seen how many pros are going narrower and narrower. It is to reduce the frontal area of your body, and really improve aero.

This obviously leads to the overall importance of fit. We asked our Retül fit Guru, Scott Stroot, his thoughts and he said, “Aero bikes and aero components are most helpful if you are positioned in the most aero position your body can hold at the highest amount of power for an extended period of time. If you are not positioned well you can be losing power, aerodynamics or both. This is why a Retül fit is so essential to riders maximizing aerodynamics and power.”

If you’re riding your standard road bike in a TT or off the front w/o aero bars our WinTunnel engineer and Body Geometry Research manager said, “Simply adjusting your body position into a crouched position on the hoods or drops will improve aerodynamics. Crouching so that a rider’s forearms are flat/parallel to the ground can improve aerodynamics in the range of 6-12 W at 40 kph depending on the initial, non-crouched position.”

When it comes to aero gains with equipment across the spectrum wheels, clothing and helmet are the top 3 bang for your buck purchases.

Sam Pendred, designer of the Hope HB.TT:

• Working on developing the HB.TT further and because of the radical design, we are trying things in the wind tunnel that “usually” give riders a big gain – but the design of this bike can be counter intuitive. We have seen improvements by doing things that would normally be worse for aerodynamics (rider position, especially).

• Working heavily on parts that other brands don’t have the interest/capability to manufacture. Components can be a very interesting one, like the front caliper on the HB.TT – a brand new caliper design that sits perfectly to the fork and behind the axle of the front wheel, with not a single section of exposed hose. We are looking at doing other interesting things like this with more components in the future.

• Manufacturing capability. This is a big stumbling point for lots of designs where the design is great but you can’t find a way to make it. With everything done in house here at Hope from mould/component machining – to laminating the composite products – finishing & assembly. We have total control over the whole process and it allows us to push it further and try new complex designs (usually) with high levels of success.

Got a question of your own? Click here to use the Ask A Stupid Question form to submit questions on any cycling-related topic of your choice, and we’ll get the experts to answer them for you!

The post AASQ #141: Which aero components offer best bang-for-buck drag reduction? appeared first on Bikerumor.

We know, there’s no such thing as a stupid question. But there are some questions you might not want to ask your local shop or riding buddies. AASQ is our weekly series where we get to the bottom of your questions – serious or otherwise. Hit the link at the bottom of the post to submit your own question.

Welcome back to Bikerumor’s Ask A Stupid Question series. This week we’re keeping it short and sweet, focusing the spotlight on something important to all riders; handlebar position. If you’ve never played around with bar roll, it could definitely be worth experimenting with to find the most confidence inspiring position. If the bar roll is slightly out, it can have a significant impact on the bike’s handling. This week, we put your question to the experts at Fasst Co, Burgtec, Ritchey and FUNN in order to find out the roll position their bars are designed to be ridden in.

• Jason Parsons, Sales Manager at Fasst Co
• Dan Critchlow, Head Honcho and Potions Master at Burgtec
• Fergus Liam, US Marketing Manager at Ritchey Logic
• Dominic Loh at FUNN

I am having an argument with a friend on how riser bars are supposed to be installed in terms of roll angle. My view is that the default position is to have the rise parallel to the forks (at least for MX, that is clearly how it is supposed to be). My friend thinks the rise should be vertical to the ground. While clearly you can ride anything in between (and probably beyond), it would be interesting to hear what the design intention is from people who actually design handlebars.

Fasst Co: This is a really good question. We have a lengthy background in MX and spend more time than any other brand helping MX riders find the right bar bend. In short, we agree that the bar should be positioned as close to the plane of the front forks as comfortably possible.

Imagine you have your bar positioned neutral, as you start to roll that bar forward, the back sweep of the bar starts turning into the rise of the handles, which can create comfort issues. Rolling your bar can also make it tough to keep your elbows up. Obviously, you have a couple degrees of wiggle room to roll the bar forward or back, but from an ergonomic standpoint, if you’re rolling the bar drastically forward or back, there’s likely a better bar bend out there for you and the riding you’re doing.

With a traditional handlebar it may not matter much if a rider rolls the bar drastically, as long as they’re comfortable. But with the Flexx Ba, you’ll get the best performance running the bar close to the plane of the front fork. Your handlebar is one of the main touch points between the bike and rider. If your handlebar is in an awkward position it can be hard to find comfort and confidence in the front end.

Burgtec: We designed our bars to be ran completely neutral. Running the bars in the neutral setting allows the rider to make the most of our back and up sweep. Sure, every rider is different and they may choose to slightly adjust their bars a little bit forward or back from neutral.

But. in the main, everything is very close to neutral. If the rider tips the bar too far forward it could be that they’re trying to increase the size of the cockpit so should perhaps consider a longer stem or perhaps even a bigger frame.

Getting your bars set up correctly is absolutely crucial and can make a huge difference to the handling of your bike. This year’s World Champion Greg Minnaar uses our handlebars and he is incredibly particular about his handlebar set up. He will set up his bars at the Team testing camp in February/March and won’t adjust the bars all year once he’s happy with the set up! A lot of set up is really down to personal preference and whatever works for the rider. 

Ritchey: Generally, designs occur with the presumption the bar is on an X/Y axis in relation the ground. So, if we’re considering sweep, it’s on a plane level to the ground. Similar principles apply when considering rise and flare. However, this is mostly an aesthetic starting point.

Ride your bars how you feel most comfortable! Everybody is different and having a level bar with sweep doesn’t always work for everyone. An anecdote I have is this: one time I lined up for a crit and one of my buddies informed me the bottom of the drop should be level with the ground and not angled slightly up as I had them. I told him it was more comfortable this way, and Tom (Ritchey) didn’t care how I rode them as long as I enjoyed the ride.

FUNN: The rule of thumb for the default position has been the rise is parallel to the forks, after which, it is really about tuning it to your preferred comfortable setting. If you look at most bar markings on the angle, it is pretty much that.

Got a question of your own? Click here to use the Ask A Stupid Question form to submit questions on any cycling-related topic of your choice, and we’ll get the experts to answer them for you!

The post AASQ #140: What roll angle are riser bars designed for? appeared first on Bikerumor.