Tips for getting good profiles for track (fixed-gear) bike?
Posted: Thu May 27, 2010 8:27 pm
I want to get at least four profiles for my new track bike. This would include using standard drop handlebars versus clip-on aerobars and using training wheels versus racing wheels. The 335 meter velodrome is outdoors, has a fairly new concrete surface, and has banking of 25 degrees. No DFPM yet for this bike, but I do have an iAero. Also almost all of the wattage I will care about in both training and racing will be at well above 20 mph. There are few windows of opportunity for me to perform the calibration procedures due to the velodrome schedule and availability, so any and all advice will save me time and will be appreciated.
1. To do the 2-mile Cal Ride, I assume that all I would need to do is ride around the track for the first mile (on my local track, about 5 laps), slow down enough to trigger the signal to turn around, and then complete the second mile. Would this be good enough for a Cal Ride?
2. Looking through the docs, I don't see a way to save a profile (to upload to the iAero whenever I want) to my computer without doing Coast-Downs. Is it correct that I cannot save a Cal Ride-only profile? I'm asking this primarily because doing CDs in a velodrome might be a challenge and because this is the first time I ever thought to use this method because of the special challenge of a track.
3. Since doing CDs seems to be my only option to get the multiple profiles I want, it also seems like I should probably use the method wherein I measure CdA and estimate Crr. My reasoning is that, since this is on a track, the surface is relatively smooth compared to the road and highly consistent. Also I would expect the Crr to be fairly low, so my question would be: what might be an appropriate number or range for the Crr for my situation?
4. Would I be correct in assuming that I must unclip from the pedals when performing CDs on a fixed-gear bike? It would seem so since the pedals have to keep going around, and I wouldn't want the weight of my legs on the pedals to be a factor in slowing down, would I?
5. Slowing down from 20 mph to 8 mph for CDs fast enough in a velodrome could be problem. I recall getting bad CDs when the CD took too long. Is that true that time is a factor in the quality of a CD? I have not timed this yet, but I assume the way to do it would be to go up the bank (as gradually as possible), and then stay at the top until I get to 8 mph, hopefully under the time limit. Does that make sense?
1. To do the 2-mile Cal Ride, I assume that all I would need to do is ride around the track for the first mile (on my local track, about 5 laps), slow down enough to trigger the signal to turn around, and then complete the second mile. Would this be good enough for a Cal Ride?
2. Looking through the docs, I don't see a way to save a profile (to upload to the iAero whenever I want) to my computer without doing Coast-Downs. Is it correct that I cannot save a Cal Ride-only profile? I'm asking this primarily because doing CDs in a velodrome might be a challenge and because this is the first time I ever thought to use this method because of the special challenge of a track.
3. Since doing CDs seems to be my only option to get the multiple profiles I want, it also seems like I should probably use the method wherein I measure CdA and estimate Crr. My reasoning is that, since this is on a track, the surface is relatively smooth compared to the road and highly consistent. Also I would expect the Crr to be fairly low, so my question would be: what might be an appropriate number or range for the Crr for my situation?
4. Would I be correct in assuming that I must unclip from the pedals when performing CDs on a fixed-gear bike? It would seem so since the pedals have to keep going around, and I wouldn't want the weight of my legs on the pedals to be a factor in slowing down, would I?
5. Slowing down from 20 mph to 8 mph for CDs fast enough in a velodrome could be problem. I recall getting bad CDs when the CD took too long. Is that true that time is a factor in the quality of a CD? I have not timed this yet, but I assume the way to do it would be to go up the bank (as gradually as possible), and then stay at the top until I get to 8 mph, hopefully under the time limit. Does that make sense?