Just What Is Road Feel?

The Felt F1

When I review a bike, I tend to hit the “road feel” aspect of a bike’s ride pretty hard. I’ve done it enough and gotten enough subsequent questions about just what I mean and what I value that it seems high time I spend devoted some pixels just to the subject of road feel.

It used to be that road feel or “ride quality” was an indispensable dimension of any bike review. Even Bicycling Magazine would address it in their famously brief reviews. Those publications that devoted more than a couple hundred words to a review tended to spend more time defining not only a given bike’s ride quality but also made an effort to assign some sort of value to the quality. I’m not seeing much conversation on the subject these days, save the reviews Ben Edwards pens for peloton magazine.

While it may seem that ride quality and road feel may be essentially two different phrases for the same phenomenon, I do see them differently and I believe historically that “ride quality” was often used to define not just the feel of the frame material, but the interplay of that material with the bike’s geometry. In a nutshell, I use road feel to address the sense of road I get based on the frame material alone. It has nothing to do with the frame’s overall stiffness.

The incredibly thin walls of the F1′s bottom bracket

So any discussion of road feel is limited to the sense of road the bicycle’s frame imparts to the rider. Many of the bike’s components can affect just what you experience. Ride a bike with 100 psi in the tires and then ride it again with 140 psi in the tires and you could be forgiven for believing you were on a different bike.

Bar, bar tape, seatpost, seat and tires will all affect road feel, but none of these will usually have the effect that a significant change in tire pressure will bring. Additionally, different shorts and different shoes will affect what you experience as well. When reviewing a bike, I never get the chance to normalize for more than wheels and tires. I’ve got a set of wheels I know intimately and have some trusted open tubulars on them. That will zero out the wheel/tire combo. Ride a bike long enough and you’ll even see through differences in shorts. All that aside, the most important feedback you get comes through your feet and butt.

Okay, so all those factors can skew what you feel, but that doesn’t answer the central question of why road feel matters.

 The Felt’s head tube

Handling

I’m fascinated by road feel because it is one of a handful of the dimensions of a bike’s overall composition that can affect how I descend and corner. When a bike is pushed to its performance limit, road feel can have a profound influence on just how far I’m willing to go.

People will use descriptors such as “lively,” “dead,” “springy,” and even “razor-sharp” to discuss the way the bike feels as they ride it. That feel is road feedback. Think of your frame as a pair of glasses and the road as the sky. The frame you ride is essentially the lens color of your glasses. You can ride a frame that blots out most of the sunlight to tame a sunny day. Or it can be a high-contrast yellow lens for the low-light situations you find on early morning fall rides. And whether you choose a dark or light lens, the quality of that lens will determine the clarity with which you see.

While this may be obvious almost to redundant, the road surface has a huge influence on just what you experience. The smoother the road, the less input you get and the deader the bike will feel. Some amount of texture is helpful for descending and cornering.

The inside of the Felt’s head tube; note how thin the walls are and the fact there’s no foam around the HS cups

When I first started reviewing bikes, my sense was that the changes I experienced in road feel related almost entirely to frame material, that all bikes created from a frame material were sort of static in feel. However, the market was being flooded with new steels and I quickly learned that some of the new oversize steel tube sets (such as Columbus EL-OS Nivacrom) felt different from older stuff (such as Columbus SL). Even though the material density was the same, the bikes felt different.

So why was that? The best information I have from engineers is that it was related to wall thickness. If density remains consistent, a thinner wall will transmit more vibration. Increase wall thickness or decrease density and the feel changes. Titanium is half as dense as steel; aluminum is a third as dense as steel.

But the vibration transmission is affected by other factors. Butting makes a huge impact on road feel. No matter what material is used, if the tubes are straight gauge, the bike will have a harsher feel; more vibration will radiate through the frame.

The Cannondale SuperSix EVO

Desirable?

So what constitutes good road feel and how much vibration should a frame transmit? Well, there are a variety of opinions on this. The French manufacturer Time does all it can to eliminate as much road vibration as possible; they include materials like Kevlar to make the frames mute to vibration. There are other manufacturers, such as Specialized, Cannondale, Felt, Look, BH, Parlee and even Bottecchia that offer bikes with a nude finish; that is, decals and no paint. No paint means an absence of 80 to 100 grams of material that contributes nothing structural to the bike. When you’re talking about a potentially 800g frame, that means 10-12 percent of the bike’s weight does nothing to contribute to strength or stiffness. You might as well just wrap the frame with electrical tape.

While 80g of paint is a liability in the weight department, the presence of paint does an interesting thing to a bike’s road feel. It deadens the frame. Not terribly, but it does fundamentally change just how the bike feels.

I’ve had the opportunity to ride bikes from a couple of manufacturers with paint and then with a decal-only finish. The difference in feel has to do with high-frequency road vibration. It’s that high-frequency stuff that gives you the greatest sensitivity to the road conditions. And though Trek doesn’t offer (so far as I’ve seen) a single nude-finished frame, it’s absence suggests less that they aren’t concerned with road feel and more that they aren’t confident in the cosmetics of their unpainted frames.

While I could try to illustrate the point of sensitivity with the analogy of a condom, let’s go with a stereo instead. On a traditional stereo with volume, bass and treble controls, if you turn up the bass and then turn down the treble, you wind up with gangsta rap—a pumping sound that has little definition. Carbon fiber frames with nude finishes feature a little less volume overall (because the frames feature an incredible amount of internal butting at junctions) but offer clarity that can only come from keeping the treble cranked up. Think of top-40 radio and the way those melodies can carry even when played on a lousy department store PA.

The EVO’s seat cluster

The Trouble With Color

Painted carbon can look amazing. It can also give a manufacturer the opportunity to cover blemishes in substandard work. It even offers a very minor degree of impact resistance. But it does nothing for road feel.

Bikes like the Specialized Tarmac, Cannondale SuperSix EVO, Felt F-series and BH Ultralight feature next-generation carbon fiber construction that has eliminated the use of foam in junctions where compaction has traditionally been a problem. Internal forms help make sure the bike achieves optimal material compaction. I suppose there are others using these techniques, but these are the bikes I’m aware of so far. Tap a fingernail on the down tube of one of these bikes and you’ll hear a distinctly metallic sound. The greater the material density, the higher frequency the sound. Both frame strength and road feel benefit.

It’s easy to conclude that greater high-frequency sensitivity is strictly an aesthetic preference and that one can make a strong case for a frame that stamps out vibration like ants in a kitchen. Unfortunately, there are objective reasons to seek out a frame with less vibration damping.

If your goal is a frame that maximizes strength while still achieving a competitive ~800g weight, you have to go with a nude finish. I’ve yet to come across a bike that offers the strength and weight equal to the world’s top frames that also feels dead. I’m so glad. But, God, how I wish Cervelos were available in a paint-free scheme.

A final note: One needn’t ride on the roller coaster roads of Malibu to make use of the benefits of superior road feel. I try not to push bikes to the point of breaking the tires loose (at least, on the road), but when the roads are wet, a bike that gives me great feedback will help me get down a descent faster. And as a rider, the greatest challenge I ever face on two wheels is riding in the rain. Descending in the rain? Nearly guaranteed flow state, and it’s times like that I want all the data I can get, even if it’s 100 percent right-brained.

 

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9 comments

  1. Robot

    I’m working on a taintometer, essentially a chamois insert with a force sensor in it, that will allow you to measure road “feel” effectively. It’s sure to make me a millionaire.

    In all seriousness though, this post is exactly the reason I’m psyched to work with Padraig every day. I learn.


    1. Author
      Padraig

      Thanks for the kind words everyone.

      The music producer says I should be a music journalist. I admit one of my favorite magazines of all time was Musician. (You gotta love any magazine brave enough to run a cover line like “Why Primus Sucks.”) Today, I don’t like enough of the music being produced to stay employed. The last remotely poppy CD I purchased was Florence and the Machine. I’ve got a LOT of David Sylvian in my iTunes. Don’t think that would go over well with Rolling Stone, but man, the chance to write about really great music would be fun.

      Oh, and in a strange, former life sort-of-way, I used to write for Pop Culture Press back when it—and I—were based in Memphis. I wrote bunches of reviews for them. Peter Gabriel, Suzanne Vega, Brian Eno—all the big hits.

  2. Sidamo

    @Robot: RIDE magazine here in Oz have just started using accelerometers in their bike reviews. One on the chainstay and one on the saddle. Difference in output gives an objective measure of frame damping etc.

  3. Keep It Real

    Padraig,
    No offense but this reads to me like a mural painter trying to explain how the structural engineering was done for a building’s wall. You’re such a great writer, but your technical explanations are lacking and often completely wrong. I’ll take some bytes to explain.

    I’m sure you value road feel. But trying to explain why it’s important/better/justified, and how no paint or higher material density result in better road feel is misleading at best. Let’s not try harder to build up a mystique about things like “road feel” when talking about bike tests feels like you’re trying to convince others you’re uniquely qualified to do bike tests. It has the opposite impact.

    “Tap a fingernail on the down tube of one of these bikes and you’ll hear a distinctly metallic sound. The greater the material density, the higher frequency the sound. Both frame strength and road feel benefit.”

    How do you come up with such conclusions? There are so many errors to that statement. Where do I begin? Have you ever tapped two cans of different sizes but made of the same material? Like a Fosters and a Coke can? Or heard a small diameter wind chime compared to a large diameter one made of the same material, same thickness, same density?

    And greater material density being stronger and results in better road feel? Why aren’t we all riding bronze or gold or lead bikes? Material density is just one of so many factors here. If this density and road feel were so important wouldn’t a company be able to then offer a heavier frames with world-class road feel? One also shouldn’t confuse density with strength and strength with stiffness and stiffness with resonance.

    Nobody will argue that a supple tire doesn’t conform to road imperfections better, and on a bumpy road actually roll faster because it absorbs little bumps instead of bouncing over them. I’m guessing that’s why you use open tubulars in your tests. Smart choice, they have a nice smooth ride, right? Kinda close to tubulars?

    But then to say that you value road feel so highly? Ride higher pressure and cheaper tires so you can feel all those road imperfections and stop worrying about paint or fragile sidewalls. I promise you’ll feel everything on the road better with a 33tpi nylon tire. It’s denser too, btw.

    If you think paint has a impact in road feel, you should study resonance. Different materials have a habit of canceling out vibration. Grab a set of wind chimes and experiment. Paint some, drill holes in some, wrap some with some handlebar tape, and cut out a section of one and replace it with a different material. Paint being a different material than carbon has a really minor impact, but a couple pieces of cork tape along a tube would have a much bigger impact.

    Your last comment justifying all this by saying “superior road feel” “will help me get down a descent faster” defies all logic really and is insulting to the educated reader with any sense of physics. What happens on wet roads? A tire loses traction. The most common scenario is that in a corner a tire slides sideways when the friction isn’t great enough. A bike’s material, regardless of vibration dampening or “road feel” does not transmit a sense of friction in a corner. A wet road, if it’s not raining, unless there’s a puddle, transmits the same vibration as a dry road. The bit of coating on the surface doesn’t change road feel. All your other senses can help you – eyes for shine – ears for water sound – your skin for spray – but you’re lying to yourself if your butt/feet/hands are somehow helping you know you’re on a wet spot BEFORE you start slipping. What’s actually likely happening is that vibration or “road feel” has you going a bit slower on the downhill, and offers slightly lower traction/grip on really bumpy roads, and so you avoid crashing and feel more in control and maybe don’t overcook a corner and perhaps that makes you feel faster so you don’t have to jam on the brakes. Slow and steady wins the race, right?

    What has been proven again and again, is that your traction can be improved by more supple tires, lower pressure, softer rubber compounds, and (even micro) suspension. Micro suspension can also be called vibration absorption, or by a few folks like you, “deader.”

    What we do know from research is that all that “road feel” adds up and on imperfect roads after a long ride it will certainly make your body feel “deader.” That’s the downside of vibration, and why materials like Lycra Power have been invented. Maybe you have a bunch of those garments, and thus crave “road feel” a lot more than us mere mortals.

    See you out there. Keep up the great writing but stay clear of the technical subjects please.

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