jens wrote:
Bernoullitrial wrote:
Jens, Thanks...Do you by chance have any data? 10 watts at 50km/h is significant!
I don't, but maybe we can get Kevin to publish his data on his record attempts at Hellyer and Aguascalientes. Maybe he has already -- I haven't searched.
I can say from memory, that the concrete track was about as slow as Oregon chipseal. So tires that were testing at .003 on the rollers were like .0043 on the concrete.
First test in December 2016 I did 45.57km @313 watts. Ave cadence of around 105. cadence only fluctuated by 1-2 rpm per lap. It wasn't really a big deal at all. Cold day as you'd imagine. Temp was about 56 degrees.
Second test on April 29th, 2017. My Garmin shit the bed and I didn't get any data. Yeah, I was pretty pissed! 46.2km on the same gear as before, so a higher cadence. Maybe 107-108. It was windy that day. Windy enough that I got a couple of bruises on my right knee from whacking the top tube when the bike got blown a bit sideways coming out of turn 4. If I had to guess I would have gone around 47km that day if it was calm. Temp was upper 70's, towards 80.
Both Hellyer rides were on a Zipp disc and 808 front. Both clincher with my road TT tires. The record rides were on double FFWD discs with Vittoria Pista CS tires at 200 psi.
The final ride was in Aguascalientes. 49.121km on 277 watts. The 250 was much more to deal with than Hellyer. I was aiming for about 108 rpm average which would have given me 49.5km, but I faded a bit over the last 20 minutes. The cadence variation was a much bigger deal. As much as 4 rpm twice each lap. It was also much more of an issue riding a good, short line on the track. I did a little exploring shall we say. Especially later in the ride as I got tired.
I hadn't been on a 250m track since 1999. We did two days of testing a familiarization before our attempt. I think that with much more time on a 250 track on the lead up I could have gone significantly farther with the same fitness. I wanted to go 50km. I don't think more skill and technique would have given me that much more distance, but I think it would have been enough to maybe get me to 49.5 which as I said was my schedule on the day.
Long story short, don't underestimate the difficulties of riding a perfect line on a 250m track if you aren't used to it.
I know that Molly rides a ginormous gear, but I found that a bigger gear was harder for me as every time I came out of the turns it felt hard to get back on top of the gear for the straight away. In the end I geared down from a 53x14 to a 52x14 and was much happier for that choice.
I was quite surprised by my low power number. I did 315 watts at the district TT in Loyalton (4900') and based on Rob and Molly's data expected to land at about 305 watts in Aguascalientes. I was very OCD about doing zero offsets so I know that was good. It was a new power meter as I had been using a specialized SRM on my Transition for the testing and the BB30 obviously did not fit my BMC. I thought at the time that the calibration might have been off, but I checked that after the fact and it was very close. Since that time I've used it a bunch on my trainer this winter and the gear, cadence, power seem to be right in line with last year on the other PM. I'm not sure what conclusion to draw from that. Maybe a combination of fitness differences and the affect of the turns.
More details at kevinmetcalfe.dreamhosters.com if you are so inclined.
BTW, Norm did not have power for his hour ride. In the hustle bustle of making a last minute position change to be legal he forgot his Garmin. His number was an estimate. Probably a pretty good one.
BTW2, I think that for a properly prepared rider Aguascalientes is faster for sure. I wonder though if somebody with less experience, especially on a steep 250 meter track might go farther in Colorado Springs under the cover, on a warm day than they would in Aguascalientes.
BTW3, they never took the Colorado Springs cover off last year as far as I know. But I don't think that anything about the status of the dome is set in stone so to speak.
BTW4, the Colorado Springs velodrome director was not at all interested in doing an hour record day last year. In fact if you got a group of three or four riders on one day to do hour records, the price would be the same per person as just a one off. No bulk discounts, even though the expenses don't go up much by running multiple riders. In the end it was as cheap or cheaper for us to fly to Aguascalientes and do the attempt there there it would have been to go to Colorado. (We had a large group in Mexico.) FYI, our prices including flying in a UCI commisaire from Colorado for our attempts.
Kevin
http://kevinmetcalfe.dreamhosters.com My Strava