Originally Posted by
Zaskar
Any rim/tire/brake setup can be perfectly safe or very dangerous. It's the rider (technique) not the gear.
You have front and rear brakes - use them.
Don't ride the brakes to stay at a given speed - use the brakes intermittently to scrub off enough to go below your target speed - hard on, totally off, hard on, totally off. I'll explain. If you want to average 35 mph on the decent, coast to 40, brake hard enough to slow to 30... coast to 40, repeat. Don't ride the brakes at 35 to stay at 35. That's how things overheat.
That's my technique, too, on my aluminum rims. Hard brake, let go. I alternate front and back wheels if possible.
But-- that really doesn't work on steep downhills. I don't know the cutoff point, but somewhere around 10% grade, the bike regains it's speed "instantly". The brakes are working almost continuously.
Probably, stopping for a cooldown is the only good solution here.
I do find that keeping my speed slowed way down does help. The braking force in my fingers is lower. That has to affect rim heating.