I suspect the difference is so small that it’s silly to even ask… but I’ll ask anyway. How much of an aero impact is there between the following wheels:
2006 (pre firecrest) Zipp 808 with aluminum brake track
2013 Zipp 404 Firecrest
2012/13 Zipp 808 Firecrest
I am aware that a deeper front wheel has more aero impact (if you can control it), but I haven’t seen much data on the impact of just the rear wheel (without changing the front wheel). As I said, I’m just curious… and I have a rear 2013 Zipp 404 and a 2006 Zipp 808 (non FC with aluminum brake track).
The improvement is non-negligible. The Firecrest shape concept reduced drag on the rear half of the wheel more than the front, so the drag savings on the rear wheel are proportionally larger than with most aero wheels/rims. You are easily looking at 1-2 watts saved from older 808 to 404FC rear wheel and another 1-2 watts from 404FC to 808 FC. Actually, looking at my old data, it’ll be even more than that because that’s using the 808 tubular as a baseline and the tubular was definitely faster than the old aluminum brake track 808 clincher…
Josh
Actually, looking at my old data, it’ll be even more than that because that’s using the 808 tubular as a baseline and the tubular was definitely faster than the old aluminum brake track 808 clincher…
I’m interested in that! I’m running the old 808 clincher on the front with a 20mm Supersonic. I’ve seen data on the 808 tubular of the same era, but wondered how much worse the clincher would be.
The old 808 clincher will do best with a good 20mm tire like the supersonic, but will still be slower than something like an 808 firecrest with 23mm GP4000s by a few watts across the board.
Thanks Josh… kinda figured that would be the case. Looks like I can look forward to spending some money and going a wee bit faster… or just compensate for being over the hill…