How much faster

Triathlon Forum
1

This season I raced on a Renn disc and an American Classic 420 (without bladed spokes). How much faster would I be with a Hed Alps on the front over 40-60k? The AC 420 has a 34mm rim depth. I can average about 22 - 24 mph over 40 - 60k depending on the terrain. $450 bucks for how much time?

Thanks

2

20-30 seconds over 40-60K.

Dave

3

The 420 is a very non-aero rim despite the depth. The profile is circa 1980s, see:

http://www.zipp.com/tech/documents/ANoteonRimWidth_002.pdf

You’ll gain 0.1 to 0.2lb of drag which at 23mph is worth something on the order of 0.3 to 0.5mph average speed. Or on 112 about 6 minutes maxiumum savings (90 secs on 40k). Don’t use a 23mm front tire or you’ll throw away most of the savings…20mm only for the front.

Also consider the Spinergy Stealth SS for another good front wheel. I use it with a Renn rear and average about 22 on 90k flat courses. The front runs about $300 for the SS version and it’s fast and very comfy. The Hed should be similar, and both way better in road comfort than the AC 420.