Little Things

So here is a proposition for you: We can't tell if we are riding well or not.

Obviously I don't mean this on the very off days - some days we are slow as a turtle, but it surprising to me how little difference in time there is from one day to another, and one weather condition to another.

A few background items:

The nearest downhill behind my house takes 10 minutes (the trail is growing periodically so this will get longer). My PB was set a few weeks ago, the day after a rain the on the Niner. There was no dust and traction was solid. A couple days ago I did the DH twice. This was the first ride for the Cdale Caffeine, conditions a bit dusty a loose. My times were separated by 4 seconds over the 10 minutes, and the second run was 8 seconds slower than my PB. Incidentally, my second fastest time was on the Spider at PB+6 seconds.

Different days, different bikes, all within 1 percent.

Another example is the Clarks climb, which Bp and I have done a few times. He had mentioned his best time over the past few weeks, so I thought I'd do it. I remembered the time wrong and thought I was much slower, but it turned out I was 4 seconds slower - 0.7%. Even more surprising was his single-speed ride, which was within 10 seconds. On Tuesday I got out to repeat the climb, though on the Caffeine, and I came in at about 15 seconds faster - about 2.5%.

My last interesting example is the Evanston race, in which the fast guys dropped me in the first 10 minutes, never to be seen again. In the end Alex won and beat me by 1.6% (he could surely have gone faster if someone was pushing him, but anyway...)

The best power-meters (powertap, etc) are accurate to within plus-minus 2% (in the case of SRM, only if you calibrate it yourself - factory calibration is worse). In other words, the powermeter can't reliably tell which of these rides would have been fast or slow.

With margins like these, it is no wonder pro riders obsess over ever detail. The question becomes how much, and how can you tell? I question whether riders can really feel a 1% difference. For me a 1% difference at threshold is approximately 3 watts -- tiny.

It also opens the door for a lot of quackery. It is easy to sell something when it might help, but there is no good way to tell if it is really helping or not.

Ok, I'm under pressure to go load the car for Thanksgiving. Later.