Originally Posted by
andrewclaus
Braking with the rear brake is more stable, I think. I was taught to start braking with the rear, then add the front for a quicker "panic" stop if needed. The front wheel has less weight on it on a typical road bike, and is therefore easier to brake which is not always a good thing. In an extreme front-only stop, you could pitch over the front wheel. I picture it as throwing an anchor behind you rather than a block in front of you.
I suggest reading Sheldon Brown's page on braking.
http://sheldonbrown.com/brakturn.html When I first started coming to bikeforums I was one of those who used thier rear brake 90% of the time. I've since trained myself to instead use the front brake 90% of the time and I can feel a massive difference. It's so much safer, and it works better.