Thoughts On Wheel Vibration Damping

Berd spokes: Do they actually make the wheel more comfortable?

 Over this past week I got a question in the comments section regarding wheel vibration damping and if that was really a thing, or just a bunch of speculative, traditional, accepted bicycle lore that, in reality, doesn't exist. 

I do not claim to be a scientist, but I have read a lot of reports, listened to a lot of wise wheel people, and I have built hundreds of bicycle wheels. I have tested some of the most exotic combinations of materials for spokes and I have ridden some really bad designs. 

So, with my experience, learned over 30 years of being a mechanic, and with my lifetime of riding bicycles over 50 years now, I offer these thoughts and opinions on the subject. I'm not trying to sell you anything, and I am not trying to sell anyone else's stuff here. The following text is just my opinions on this subject, plain and simple. 

First of all, the dynamics of how a wheel system works might surprise you. I know when I learned what was actually going on with a rider on a bicycle when it comes to how a wheel works, I was a bit surprised. I'm not going to delve into all of that here, but I strongly recommend that you check out the subject. You could do worse than start here and in that short video you will see that there is a LOT of nerding out one can do on the subject of wheels. 

I'm sticking to wheel vibration damping characteristics and whether or not those are real or imagined. First off, what is 'damping' in terms of vibrations? (Hint- click the link) Essentially, in terms of what I am thinking about practically, I need to erase those pesky vibrations from crushed rock roads from buzzing my hands, feet, and rear end so I don't get fatigued as quickly, or go numb because my body is absorbing- or damping- that energy. 

The first line of defense: Your tires make the biggest difference of all in ride quality.

Obviously, we cannot discuss how a wheel damps vibrations, or even if it can, without discussing tires, because, well, no one should be riding on bare rims. We all are using tires. So that has to be included here. This is your first, and most effective part of the wheel system when it comes to damping vibrations. Tire air pressure is also critical. 

And again- I can write about that all day. But you must understand that how tires can work for you is WAY more important here than how the rest of the wheel will affect the ride. What a wheel might be able to add to the ride feel, vibration damping, and overall joy of your experience is minimized by how you choose a tire and how you choose to run it. (air pressure, tubed, tubeless) 

What is left over in terms of wheel ride feel is what vibrations are coming through the wheel system and then getting transferred into the fork/frame. Different materials will attenuate those frequencies, but they will not eliminate them. For instance, lower amplitude vibrations often are going to affect you as a rider no matter what you do, save running suspension components. But the good news is that those types of vibrations are not really the ones that knock you out so much as the high frequency ones do, which in my experience can be mostly attenuated out of the ride feel on a bicycle.(And not necessarily by using a wheel solution, by the way.)

The FLO Cycling wheels appeared too stiff- but were exactly the opposite of stiff.

So, to get rid of that energy we call vibration you need to dissipate it or absorb it. Dissipation of energy typically is a situation where something turns that energy into heat. Something typically has to move. Spokes don't typically 'move' per se', not in the traditional sense. They tension and lose tension, and they vibrate, at least steel spokes do. They are great at transferring vibration, and not so great at dissipating energy. Rims are not usually an ideal place to have vertical deflection, because - in a traditional rim design, that loads and unloads spokes even more which can lead to premature failures. Ideally, we don't want any rim deflection in a traditional wheel build, although- obviously- there is some. (See video linked in 4th paragraph)  

So, your carbon rim with typical steel spokes is not going to have a lot of vibration damping effect because it is designed to be stiff as all get-out. Especially so if it has low spoke count design. So where can we see a rim/spoke/hub set up that does have this vibration-eating quality? Box section rims? Interestingly, a study done on those wheels traditionally thought to be cobblestone dominating wheels, found them to be stiffer than modern wheels over cobbles! So, maybe that old saw that box section rims had some magical 'give' to them is just an old racers tale. 

Okay, so what could work? Well, a rim that actually deformed and damped vibrations without affecting the spokes. Or, spokes that actually stretched and compressed. Are there such things? Yes, there are. 

I tested a set of wheels from FLO Cycling with an aero profile, and while that is a whole 'nuther subject as well, the main benefit, in my opinion, was how the cross section of the rim worked. These were deep section wheels with the spokes attached at the innermost diameter of the rim, (think- at the pointy end towards the hub), and the deep section was kind of a bulged out, triangular shape in profile up to the wide rim bed. This "bulged out" section made a hollow interior. This allowed FLO Cycling to thin out those wall sections to where they actually flexed outward a bit when riding, and rougher surfaces activated this hysteresis (think like a tire deformation over a road surface) and that actually does something for you. Now keep in mind, the spokes are not a part of that section of the wheel, so this is why it can work. 

Berd spokes are woven fibers, and stretch like a rope.

I also tested, (at the same time period in 2020, ironically) a set of wheels which featured the amazing Berd fiber spokes. These woven spokes stretch and deform like a rope might do, and so they can also act in a similar way by hysteresis to damp vibrations and again- I could feel this. It was an attenuation of different frequencies than the FLO wheel set, but it was actually doing something a rider could benefit from. In a bit less dramatic way, the Spinergy GX and GXX wheels also do this. Not surprisingly those have fiber based spokes also.

So, in these instances, at least, where radically different design and material approaches were applied to wheel design, I think that you can expect a vibration damping benefit. However; when it comes to designs where the end result is more traditional, I have to raise an eyebrow here. 

While there may be some degree of vibration damping going on with more traditional wheel design models, it is minimal, at best, and your tire choice and the way that you set that tire up is going to have far, far more impact than the wheel will on vibration damping. I just don't see a wheel, in the traditional bicycle design sense, as being much of a benefit in this case. I think you have to look to these exotic solutions for any significant vibration damping effects. 

And then again, you have vibration damping handle bars, grips, saddles, stems, and gloves, bib shorts, and on and on. Bicycle fit is a huge thing here as well. There is just so much you can look at and do for yourself to find your "happy place". So, don't get lost in the weeds in wheel design, that is, unless that's your thing to nerd-out on. 

So, those are my thoughts, in general, on whether or not you can get a wheel to be a vibration damping device. Certainly, every wheel does this to a degree. But does that matter when the tire can be such a better way to get there? The only times I see that question being answered differently than "No" is where you have solutions like FLO Cycling and Berd. (And to a lesser extent- Spinergy PBO spokes) Then, yes, you are getting what you are looking for in a significant way. Those aren't the only solutions, I am sure, but those are the ones I am most familiar with that "do something" and are not just marketing-speak. 

Thanks for reading Guitar Ted Productions!