Bicycle Mechanics - Slipping brakes

I started commuting to work 2-3 times a week. I took a spill my very first day and am still a little overanxious when riding down a hill. My problem is that when I am going down a steep hill (and I have a few on my commute) I occasionally have my rear brake slip when I apply it. Pumping my brakes has worked to slow my bike when this happens, but it is freaking me out.

I am riding on a dry, smooth road so what would cause the brakes to slip?

briley: Welcome to the forums. By slip to you mean skid - leaving a black mark on the road behind you?

Also, are you using the front brakes at all? The safest way to slow down is to slowly and smoothly apply both brakes.

Give it a try on flat ground until you get used to this braking method.

Good Luck!

Zack

What kind of brake, that is what style brake, cantilever, linear, caliper? What kind of Rim, steel, alluminum? And what kind of pads?

Contrary to popular belief, the front brake is much safer to use than the rear. As you slow down, the weight of the bike is transfered forward. The traction on the front increases, and the rear decreases. It is then very easy for the rear wheel to break out from under the bike in a skid.
The front brake will not send you flying over the handlebars or crashing to the ground. It is the primary brake of a bicycle.
For slowing down, you need to "feather" the brakes. You can use the front or the rear. I often apply them alternately in quick succession. The trick is to modulate your braking power, so you apply just enough to do the job.
If your brakes are slipping on the rims, you may have contamination from chain lube. be careful that oil does not drip onto the rim when you apply it.
Wash your rims with detergent. Check your brake blocks for any stones or glass that may become embedded in the rubber, these will gouge out the rim surface. Clean the blocks with an old toothbrush if they are oily.

i use the front brakes most of the time... If you lock the rear wheel, you could easily spin/skid and scrape the asphalt.

I only use the rear breaks, gently for control, when i feel the front wheel will slip when i'm riding on loose/slippery ground/roads.

For faster stops I use both. Applying more on the front and use the rear for control.

Don't worry on going over the handle bars. People that go over the handle bars are those that use the rear brakes a lot, and out of panic, used the front brake to stop.

Practice using the front brake..

One more question -- how big is the gap between the brake handle and the handlebar when you really apply the brake?