Question: My training roads include very steep descents, many with sharp switchbacks. I try to avoid riding the brakes, but sometimes tubes blow out because the rims get so hot. I’ve nearly crashed twice. Do you have any pointers to avoid this? — Shirley M.
Coach Fred Matheny Replies: On a road with numerous steep downhill corners, the trick is to let the bike run on the straights, then brake firmly to a safe speed as a corner approaches.
If the pads are on the rim (even lightly) for the whole descent, the heating effect is usually much greater than if you stay off the brakes so the rims can cool, then apply the pads harder for brief periods. Try it (carefully!) and see how it works for you.
That’s the technique I use on long mountain descents here in western Colorado. Red Mountain Pass, for example, is a 13-mile, 3,400-vertical-foot plummet into the town of Ouray. It has dozens of switchbacks and tight corners. If I rode the brakes and blew a tube, I might take an unplanned detour over a 300-foot cliff!
However, the steeper the road and more tightly spaced the corners, the more you need to stay on the brakes to control speed. On the 3-mile, 16% drop into Black Canyon National Park’s East Portal just outside my town, the road is so precipitous — and the corners come so quickly — that you can’t let the bike run. Speed would increase so rapidly you’d be unable to slow enough to negotiate the next corner.
In such a situation, braking must be strong enough to keep the bike fully under control. If a tube does blow, you won’t be going fast enough to crash badly (a good theory, anyway).
Help keep rim temps down by alternately braking with the front and then the rear, but never the front only when actually turning. When using the front brake alone, feather it (don’t grab it) and keep your weight back.