Originally Posted by
calyco
How do you brake on downhill and flat ground? Occasionally I have been hitting like 35-45mph and thinking about it. Normally, if I need to stop fast I would squeeze the front brake for about 3 seconds, push back and put my weight on the saddle then squeeze the rear brake (while still on the front). I would hold both brakes for like 3-5 seconds and avoid obstacle or let go of just the front brake, then trail to a stop with the rear brake. If at like 15mph/cruising I do opposite, rear brake first for 3 seconds and then front brake if necessary. Its not a technique for me, just basically natural reflex.
Lots of strange things being said in this thread. Here's the real deal.
Primary braking force limitation is maintaining static friction in the tires (IE, not locking them up). Hence, anti-lock brakes. So, the number 1 goal of top tier braking is to apply the most force possible without locking up the tires.
Our focus will then be on weight distribution. Why? Because the amount of braking force you can apply is before locking up the wheel is going to be related to the NORMAL force on the tire. Normal force is important, because that means gravity works differently based on the incline you are on. In any case, the balance of front/rear braking force should match the weight distribution as closely as possible.
So, let's do a few different scenarios. Going on a flat road at 25mph. Without doing the math, I'd guess at least 90%+ of the braking force is going to come from the front brakes. As a trick, you can apply slight pressure to the rear- when you feel the rear brakes begin to lock or slide, you know you need to back off the front because your rear is beginning to lift. As the next trick, it's always best to sit UP and BACK as far as possible- this not only keeps the weight distribution as even as possible, but it also creates significant drag force which provides significant deceleration and moves the effective moment even further back. Final trick, as mentioned above, is to "set" yourself and your bike into a rear-weight position by applying the rear brake instantly before applying the front. This is less important in bikes, because there is no suspension. In cars, not only is it important for braking, but in every corner great drives will "set" their car.
Next situation, going at a 15% decline at significant speed. This is more difficult, because the room for error is very small. That's because as the normal angle deviates from straight down, the role gravity plays reduces exponentially. So, if your rear tire comes up an extra 10 degrees, it will require an extensively larger correction than if the rear wheel comes up 10 degrees on a flat road.
TL;DR: Primary braking is almost always the front brake, but you should apply both, pressure the front hard, and "feel" with the rear. Be careful on declines.