What is meant by a wheel being compliant?

[artemidorus]

One or more randomized double blinded population studies are required...

At the end of the day, irrespective what lab test data shows, if population studies can show a significant difference, then the engineers will just have to go back and see what physical parameter or analytical interpretation they've missed in the testing.

Now you're talking. Outcome studies are always the best, as long as they are done properly. My money will be on the "no difference in comfort" bet.

 

[artemidorus]

Why don't Paris-Roubaix riders typically use deep rim wheels? I understand that most choose box rims for that race as opposed to any of the deeper rims (non-CF). I may be wrong, but the explanations I've read have all related to ride comfort. Is that not the case?

If that was the reason, then one really has to question whether there's some truth in it or they are all wrong. And then just what they are sensing if min-max deflection wasn't the parameter?

I think that they'd be putting reliability above comfort.

 

[sogood]

Now you're talking. Outcome studies are always the best, as long as they are done properly. My money will be on the "no difference in comfort" bet.

Well, that's the big unknown isn't it? And the question is how big that difference is? A small different would require a far larger study. Then again, if the difference is that small, 1) Opinion would not be so one sided on the net. 2) Why bother?

 

[sogood]

I think that they'd be putting reliability above comfort.

Without even going into CF rims, are you suggesting those 25mm box rims are more reliable than those 35mm alloy rims?

 

[artemidorus]

Without even going into CF rims, are you suggesting those 25mm box rims are more reliable than those 35mm alloy rims?

I'm suggesting that they may be perceived as more reliable.

 

[CAMPYBOB]

Re: P-R

Big George (and several other racers) have used deep aero-section rims in P-R. In George's case, the lack of compliance may have been what killed his heavy-duty alloy steerer tube...oops, great call, guys! Maybe balsa wood next time?

http://www.cyclingnews.com/photos/2006/apr06/roubaix06/index.php?id=s002

Some folks will go to any length to get the important aero advantage out on the smooth stretches in the pave races. Risk management, such as it is.

Your point is well taken though that most riders do go with old school wheels to lessen the pounding. It's just another of those generalisations that science is working hard to shatter on the internet. Afterall, you sure can't feel pave in your butt, right?

 

[Dietmar]

The pragmatic argument is whether any given wheel is more comfortable than another.

I agree, so that is what we should be testing, noting, however, that "comfort" is a tricky subject. But absent data from such tests, this whole debate is just so much hot air.

 

[alienator]

Alienator, would you like to hypothesise as to why this is so? This could support the arguments of those who believe that deep carbon rims are comfier, something that has always sounded like BS to me. If it is not vertical compliance difference, then what is it? Is it a big difference, or one near the limits of measurement?

I think the reasons are bound up in the construction method/layup schedule and materials. The difference was not small in the test. The test actually is a result of the claim that people made that deep rims provide a ride too harsh for Paris Roubaix. Given the normal magnitudes of wheel deflection in plane, I didn't think that claim made any sense, especially in light of the large profile tires and lower pressures that riders use in P-R.

 

[sogood]

How about keeping it simple and just compare alloy rims of different depth in the first place? Then there's CF box rim and CF deep rim.

 

[alienator]

How about keeping it simple and just compare alloy rims of different depth in the first place? Then there's CF box rim and CF deep rim.

I chose the rims I did because it's been said many times that the traditional type wheel--alloy box section, high spoke count--is the standard for comfort and the go-to rim for P-R riders and mechanics. The span of wheel technology and development is bookended--at least at P-R--by deep section CF wheels and low section alloy wheels, like OP's.

In general use, low section CF rims are still a relative rarity, while deep CF rims are now common place. In that light, the tests were more relevant using alloy low section rims and CF deep rims.