We rode a loop of the IM USA course this am. I was really looking forward to riding this course with power, since when I did the race two years ago I rode blind (malfunctioning computer) and totally roasted myself on the first loop. The plan for me today was to simulate IM race pace by averaging about 70-75% of FTP, and try not to exceed 90% of FTP on any of the climbs. This was really an eye-opening ride for me versus how I rode the course in the race. While my absolute FTP is pretty decent, I am heavy at 90kg so w/kg isn’t great, and on these hills w/kg rules.
It quickly became apparent that if you focus on speed and average speed, you will quickly be demoralized and likely go WAY too hard in the first 7 miles of the bike. Sticking to my power and ignoring speed, I felt like I was crawling up the hills out of town. I used a lot of the 39×25. By the time I got to first “truck going down a hill” caution sign, my average speed was only 16.5 mph and average watts was a bit high at 245. Then you bomb down the 4 mile descent in to Keene, and voila, the average speed is over 21 – cool. Without the power meter keeping me in check, I would easily have ridden 120%+ of FTP on many of those climbs, burning several matches in the process.
The next section of the course is the fast section from Keene to Jay. And this year you pass Jay and ride another 5.6 miles to Ausable Forks. This out and back replaces the old out and back, and is much flatter and faster. So you now get about 20 miles straight of nice aero cruising roads. We easily averaged 22+ mph for these 20+ miles at about 220 watts.
Then the party is over – the right turn towards Wilmington and the first 1.5 mile climb begins a long painful deterioration of the nice average speed you have worked so hard to accumulate. The short story here is that from this point back to town (about 20 miles) we averaged about 17 mph at an average power of about 235 for me. Once again there was a lot of 39×25, 10 mph action. This year’s course still uses the flat first mile of the old out and back, so you skip the hills on this section. But there are still plenty of long climbs with 10% grade sections all the way back to town. To keep my power under control, I had to go SLOW and spin easily.
So the net effect, remembering that no race wheels were used, no aero helmets, and we had flappy vests on, was a time a little bit under 2:50 at 230 watts average for me. Lis averaged about 172. This really isn’t much slower than I raced it two years ago, except that I did the first loop in something like 2:38 and the second well over 2:50 if I recall correctly – ouch.
So if there ever was a course to be a slave to your power meter on, this is it. If I had to race it without one now, I’d just drop it to my lowest gear on every big climb and spin. Anything harder than that and you are really asking for trouble on the run. Ask me how I know…