|TT faster with a fixie...||B123|
Nov 22, 2002 10:53 PM
|Over the summer I did a few time trials with my normal geared bike and with my track bike. Both with the same aerobars, same conditions, both similar bar height, shorter crank arms on the fixie and 49x15 gear.
The TT was 10mi perfectly flat and I was consistently faster on the fixie. Why? Maybe extra motivation...
Any ideas? I know Adham Sbieth won the Nat TT on a fixie with a 56x11.
|No choice but to make it work?||Tig|
Nov 23, 2002 1:08 PM
|Like climbing in a fixed gear, you have no choice but to push the gear hard enough to avoid a too slow, inefficient cadence. Instead of a hill, you have a TT in a high gear to motivate you to keep it going. Since there are no gear choices to recover and relax with, you stick to it with what energy you have. If you never rode fixed and tried to do the TT on one suddenly, I bet you (or most anyone) would have difficulty and wouldn't do nearly as good. Like Humma said, a fixed gear forces you to widen your power band and develop speed and power. Going from fixed to derailleurs gives us a great advantage as long as the gearing we choose isn't too low or high.
Also, the gear ratio you used (close to a 52 X 16) is great for a short 10 mile TT, depending on a rider's abilities and preferences.
|My Non-Expert Answer||timfire|
Nov 25, 2002 11:39 AM
|I don't claim to be an expert, but what I've been told is that "all-things-being-equal," a fixed gear with its simplified drivetrain and straight chainline has less friction than the comparable gear on a geared bike, and thus in other words, faster. To quote the guru himself, Sheldon Brown,
"A properly set-up fixed gear has a perfectly straight chainline. This, plus the abscence of derailer pulleys, makes a real improvement in the drive-train efficiency, an improvement you can feel."
But with that said, "all-things" are rarely "equal." Are you sure there aren't minor different between the two the two bikes that might be causing the difference? Maybe the position on the Fixie is slightly more aero. If you primarily ride the fixie, maybe you got a littel out of practice with the geared bike and that's whats causing the difference. When talking two bikes there are a number of things that could be affecting your times, and without examing you on the bike in person, I doubt anyone can answer your question over the internet.
|I think its probably motivation||B123|
Nov 26, 2002 11:40 PM
|I think you are right about "equal". It was pretty cool to be the only guy there on a track bike...without brakes too. That combined with a large gear must have forced me to go a little harder. But if that's all it takes to be competitive in the TT's, then its fixie from now on!|
|Same experience on my singlespeed||Silverback|
Nov 29, 2002 8:42 AM
|I'm still working up the courage to build a fixie, but when I converted an old tourer to SS, I took it around a course I ride often, to see if I was close on the gearing and if I could make all the hills. I expected to be quite a bit slower, but my first ride yielded times faster than my average, close to a personal best. I'm guessing it's mainly because you can't slack off without rolling down the hill backward and crashing....|| |