Switching to the Bontrager X-Lite Aero's has eliminated the speed problem, did the 20K in 28:15 which was good enough for 2nd in Cat 4. It would only have been 3rd if it had been a combined Cat 4/5, Andy Everson from Comox finished in 27:04. but was racing as Cat 5.
Note that power is almost identical for the two events, 316 vs 317 average watts.
Gerry van Ganz was 18 seconds back after beating me by 1:20 last week for the Aldergrove 16k TT.
Aldergrove had a slightly higher wind on the return leg than Warpspeed. But not enough to account for the difference in speed.
I can only conclude that the Zipp 404's with Tufo S33 Special tubulars where simply a very slow combination. See also Wheel Testing post.
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Sunday, May 13, 2007
Tuesday, May 8, 2007
The last three TT's have been very slow. Even though I have been producing good power numbers, the times have been poor. Barely better (if) than last year. And people I should be matching have been getting times minutes(!) better.
For example at Aldergrove Bill Riley was 23:04 and Gerry van Ganz was 23:10. With me back at 24:21.
So I decided to look at the bike and see if there where any potential problems. And decided it could be the Zipp 404's with Tufo S33 tubulars.
To test I went out to Neaves road and did two tests each to compare the Zipps against my tried and true (and cheap) Bontrager Lite Aero (aluminum) wheels. Each test was 2.5 k out and back (5k total). Tests at 36kph and 42kph.
The results seem to be unequivocal, every Zipp test had higher average power for lower average speed.
Possibly by as much as 20 - 30 watts.