Originally Posted by
vantassell
I alternate to allow each brake/rim time to cool. It seems that extended periods of light braking heat up the rim greater than equivalent (mph slowed down) than quick hard braking does. I've never tested this, but it just seems to be the case from my anecdotal evidence.
Yes, that's correct. The way to arrive at the bottom of the hill with the coolest rims and brakes is to use your brakes only at 100% in short bursts. That's because the delta-T will be greatest when you use the brakes 100% and the cooling-rate (total BTUs shed per second) will be highest as well. Feathering the brakes for extended times at less than 100% is the way to generate the highest amounts of heat-buildup. I know, it seems counter-intuitive, but give it a try.
Anyway, terminal velocity on a 20% grade is like 50-60mph, why bother using the brakes at all? Just slam it on 100% for 3-5 seconds to slow down to 30mph for the corners and let off the brakes the rest of the way.