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Which wheels will be faster?????(11 posts)

Which wheels will be faster?????sigepf94
Dec 4, 2003 7:40 AM
I'm deciding between two sets of wheels for my new bike:

Option 1: Sun Venus 25MM, 28 front and 32 rear with alloy nipples and Sapim CX-Ray Spokes. Total weight without skewers is 1573g.

Option 2: Velocity Deep V 30MM, 24 front 28 rear with alloy nipples and Sapim CX-Ray Spokes. Total weight without skewers is 1645g.

Which one of these wheels sets would be the fastest over a moderate conditions course that is about 25 miles in length. Everything else on the bike will be identical including the rider. What do you guys think. Will analyticcycling.com help.

Thanks,
Mark
Assuming similarly shaped...Dwayne Barry
Dec 4, 2003 7:50 AM
rims almost assuredly #2 because it would appear to be more aero and aero considerations are far, far more significant than weight in determining time saved by wheel choice. But given that, the wheels don't appear all that different in their aero qualities. I would guess a few seconds, no more than a couple dozen seconds would be the difference.
Are crosswinds a factor?BowWow
Dec 4, 2003 8:40 AM
If there are significant crosswinds on the course, wouldn't a flatter rim be more efficient/speedy? (I don't know, myself...)
It is my understanding....Dwayne Barry
Dec 4, 2003 9:14 AM
that the advantage gained with aero rims is even greater in crosswinds than still air. Only handling is compromised. I ride 58cm Cosmic Carbones, and the only real danger that I've experienced is you get a sail effect if you're cornering into the wind that tends to push you wide. I've never descended real mountains with them, but I suspect this could be a bit disconcerting going really fast downhill.
deep Vscyclopathic
Dec 4, 2003 9:01 AM
depends on power output and hill factor, but with exception of very weak rider climbing mnt Washington better aerodynamics (fewer spokes and aero rim) will outweigh extra 82g.

BTW you can get Deep Vs in 18h and 16, if the set being built you can go with 18/24.
Unless you'll be riding in a packBonked
Dec 4, 2003 11:01 AM
in which case I would go with the lighter wheels. Sitting in the middle of the bunch, aero advantages will be minimized while weight will still matter. Furthermore, if it is a crit type situation where you'll be slowing and accelerating constantly, the weight savings will add up. However, you're talking under 80g, so I can't imagine the difference will be great.
Even in a Critasgelle
Dec 4, 2003 12:39 PM
Even stting in the pack in a crit, the aero advantage will offset the weight penalty (even for more than 80 gm). See
http://www.biketechreview.com/archive/wheel_theory.htm
I think this is perhaps the #1 misconception...Dwayne Barry
Dec 5, 2003 7:18 AM
about what factors matter for going fast on a bike. People focus so much on weight and not aerodynamics, I think because the weight of an item is so easy to know while drag is more elusive. For wheels aero trumps weight in almost every situation, except when you're going slow (i.e sustained climbing).
re: Which wheels will be faster?????lithiapark
Dec 4, 2003 12:18 PM
From what I have read of wheel aerodynamic research (Hed's website, Cervelo website, John Cobb's website and other discussions on the triathlete boards) there is only modest aerodynamic benefit to any rim less than 40mm. Hed in particular appears to say that the number of spokes is less important than this factor. These other sources of info may help you decide, good luck!
re: Which wheels will be faster?????rogue_CT1
Dec 4, 2003 11:11 PM
There will be absolutely no difference between the two. As the above post mentioned the rims are too low to give any real aero benefit and the weight difference is nill.

I have the Velocity Deep V wheels and they are not any more aero than my Ksyriums or my Mavic CXP-22's. The only wheels I've used that I could actually feel had less drag are the Specialized/Hed tri spokes. I can't really even feel the difference between my Zipp 404's and my K's.
Re: that last sentence. Maybe you can't, but I sure can! nmMShaw
Dec 5, 2003 10:26 AM