Quote Originally Posted by iowagrad View Post
So maybe this is a dumb question....but how do I actually slow down? I hit 35-40 mph at one point last summer on a downhill. I couldn't seem to help it. It was a VERY long, fairly steep hill. I was back in my saddle, judiciously braking, etc.
Feather your brakes and that can make slowing down easier.

But if you have a long descent, gravity and momentum want to take over, and you will keep speeding up. Just keep feathering those brakes to keep yourself to a manageable speed.

It sounds like you are getting low - good positioning on your bike is important so your centre of gravity isn't too high (sitting upright on a descent is way less comfortable in terms of control than holding the drops, for example).
It sounds like you are doing the braking.

Just keep practicing on the hills, and if you truly begin to feel too unsettled then do not be bothered about stopping and either walking a bit, or starting the descent from stand-still again. You have to work out the best way to descend, and I know that my speed downhill bothers people I train and race with - some think I am waaaay too slow, others think I am waaaay too fast. The key is to find what works best for you.

Best wishes, Rave