It’s official. We have a date. I will be making an attempt on 55-59 World Hour Record (okay, “Best Hour Performance”) at the Bicentennial Velodrome in Aguascalientes, Mexico on either July 15th or 16th. We have a group of four athlete’s, Andi Smith (Women’s 50-54), Molly Van Houweling (Women’s 40-44), Dan Bryant (Men’s 45-49) and myself. We will schedule the attempts over two days as the velodrome is not air conditioned and it gets quite hot inside during the day. To maximize distance you want it as warm as you can stand without affecting your performance. Warmer air is less dense. Going when it’s still cool inside could cost you as much as a lap or two. In general there is usually a window each morning and afternoon when the temperature is in the optimal range.
The record I’ll be attempting to break is 47.773 km and was set by Jim McMurray of New Zealand in March, 2016. To do that I’ll need to ride a minimum of 191.25 laps on the 250 meter track, averaging 18.8 seconds per lap. Based on what I’ve done at sea level at Hellyer Velodrome I believe I can ride 200 laps, at 18 seconds per lap for 50 km. The schedule will need to be fine tuned as I test more and won’t really be final until doing a short test effort once we’re in Mexico. Probably a 10-15 minute race pace effort about two days before the big day.
I know what you’re saying. “Dude, you only rode 46.2km at Hellyer, how the heck to you expect to ride 50kph in Mexico?!?!” Good question. There are four parts to the answer.
- Altitude. Aguascalientes is 6,200′ above sea level. The lower air density makes a big difference. Yes, you lose about 8-10% of your sea level power, but air resistance increases by a cube factor as you go faster. The lower air density more than makes up for the power drop.
- Aguascalientes is an indoor velodrome. No wind. It was quite windy during my recent Hellyer ride, probably costing me at least 500 meters.
- Front disk wheel. Since there is no wind you can safely ride a front disk wheel. The front disk makes a tremendous difference, more than a rear disk.
- Aguascalientes is a smooth wooden track and the rolling resistance is significantly lower.
This can all be quantified and calculated reasonably well. Knowing the weather (temperature, air density, wind, etc.) and power from a ride atHellyer, you can calculate your CdA (aerodynamic drag). Knowing that and expected temperature and air density at Aguascalientes you can plug that data into a spreadsheet and get an pretty good estimate of how fast/far you’ll ride at altitude. That data points towards 50kph in Mexico for me.
As kind of sanity check I know that my 40km PR at sea level is about 3 minutes slower than my PR at 5,000′ which fits with the calculations.
My team mate Dan and I have been really lucky to have help from Gu, BMC and Inside Tracker. Gu has assigned us a nutritionist to go over our diet and recommend changes. I’ve made some changes based on her recommendations and I feel like I’ve been riding well so I think it’s helping. BMC set us up with new Time Machine TT bikes to use for the effort. Finally GU set us up with Inside Tracker to get periodic blood tests to monitor our health and nutrient levels. Many of the diet changes I’ve made have been based on those results.