RCRW Carbon Wheelset 31mm wide 25mm internal

[WWcyclist]

V profiles are okay, but not like this, has to be curved

The one that I linked in the original post doesn't seem like a V?

[toxin]

Actual market leaders (i.e. CRW Works, Roval Rapide CLX II) don't use v-shape profiles. Zipps are trash tier wheels in general.

CRW were never a market leader in rim design. What they actually excel at, is hub design, and they were the first ones brave enough to actually make proper use of carbon spokes and significantly reduce spoke count. The hubs are where their weight gains came from and spoke count is where their aero came from. The profiles of their first 3 sets are all a very safe, slightly dated design, they won't give you amazing aero on their own, but they won't wreck it either.

Roval front is mostly an exercise in crosswind stability improvement. It's actually vaguely eliptical/toroidal but at that depth to width ratio, you kinda have to make it with a very wide radius nose. The rear is just a straight ellipse.

If you wanna talk other market leaders, scope are just straight up an ellipse, DT Swiss (designed by swiss side) also get more elliptical the deeper they go. Newmen are parabolical with large radii on the front. Bontrager aeolus are all parabolas with very sharp noses (and they're well regarded for their stability, interestingly enough), very similar to HED and Enve.

So there are many ways to design a rim and convergent evolution hasn't quite settled on a single approach just yet. I'm starting to think the industry moved away from the theoretical best - which is likely a toroid - because the need for a rim brake track kinda compromised its advantages and pushed design toward parabolas and U shapes that bulged out closer to the nose. Now that disc brakes got rid of that problem, it's moving back towards toroids.

Fully with you on the Zipp hate train though.

[dsveddy]

So there are many ways to design a rim and convergent evolution hasn't quite settled on a single approach just yet. I'm starting to think the industry moved away from the theoretical best - which is likely a toroid - because the need for a rim brake track kinda compromised its advantages and pushed design toward parabolas and U shapes that bulged out closer to the nose. Now that disc brakes got rid of that problem, it's moving back towards toroids.

My guess is that a symmetrical toroidal shape is unlikely to be the best true shape because the leading half of the rim gets clean airflow while the trailing half of the rim gets more turbulent flow, on average. I remember Hunt's engineers saying as much regarding the rear wheel in an interview. The fact that many manufacturers' designs are converging on parabolic shapes (what I've been calling V-ish, I think your elipsoid/parabolic descriptions are more accurate than what I've been using) reinforces my suspicion that wheel designers are finding bigger gains from optimizing the profile of the leading half and throwing the trailing half to the wind, to some extent.