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deep profile rims

Posted: Wed May 02, 2007 9:08 pm
by Parrott
Hi there, I was window shopping for wheels lately and am wondering how much aerodynamic advantage there is in a wheel with a deep profile vs lower profile?

Mavic Ksyrium ES; profile front 22mm weight 645gm
profile rear 25mm weight 840gm

Mavic Carbone SL; profile front 52mm weight 785gm
profile rear 52mm weight 980gm

The carbone wheel set weighs in 280 gm heavier than the Ksyrium yet costs about 25% more. I'm assuming the deeper profile is more aero and this is worth the weight penalty?

Posted: Wed May 02, 2007 9:34 pm
by mikesbytes
There's no exact answer;

The 52mm wheels will perform better at higher speeds, where the 22mm wheels will climb better and accelerate better.

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Posted: Wed May 02, 2007 9:35 pm
by sogood
Those are wheelsets designed for different applications. K-ES is a lightweight climbing wheel while the Carbone is deigned for speed. By internet forum accounts, a deep rim wheel like Carbone can get you around 0.4kph or less faster at 35kph speed. You are not going to find a magic wheel that'll propel you down the road 2-3 kph faster than your rivals.

BTW, air resistance isn't a significant issue until you are travelling faster than 30kph, and will increase exponentially after that. So if most of your riding are under 30kph, you are going to get even less benefit from a deep rim wheel.

Posted: Wed May 02, 2007 9:59 pm
by Parrott
Thanks for the replies. That clears it up well, I intend using them for racing which I have just started and am really enjoying. Most of the country here is flat and the group I am in averages mid to high 30's I think. Will have to wait till tax time though before I can get them past the financial controller. :?