While talented racers such...
While talented racers such as Troy Corser can use the rear brake to really set the bike up for a turn, mere mortals like the rest of us are better off keeping the wheels in line and focusing on using both brakes to set entry speed.
Photo by Gold & Goose
Perhaps the control that is most often misused on a motorcycle, the rear brake can be utilized in a variety of situations to surprisingly good effect. Ask any group how much they use the rear binder, and you'll get the whole spectrum of answers; from old-school riders that use only the rear brake, to some that won't touch it no matter what. Proper use for everyday riding lies somewhere in between those two extremes. But for a control that has very little effect on actually stopping the motorcycle, the rear brake can be used in subtle (and maybe surprising) ways to your advantage.
While making a U-turn, slipping...
While making a U-turn, slipping the clutch and keeping the revs a bit high will keep your bike stable. Modulate your speed more by using the rear brake than by either the throttle or clutch.
To master these subtleties it's first important that you are intimately familiar with your rear brake and how strong-or weak-it is, and how much its power is affected by weight transfer. First be sure that everything is in working order and correctly adjusted. The brake pedal should be a few millimeters clear of your foot when you are sitting in a comfortable position on the bike, so that your foot is not in danger of resting on it but it is easy to reach. In a clean, dry open space such as a deserted parking lot, practice coming to a stop using only the rear brake-lightly at first, then with more effort. If the brake locks at any time, keep it locked until you're at a complete stop. Releasing the brake when you are in a skid and the wheels are out of line will put you on the ground faster than you can say "oops". Experiment with both the clutch pulled in and the clutch released, and notice how the dynamics change: With the clutch out and the engine pulling the rear wheel along, you should have a lot more control over the brake and it will be much less prone to locking. Note too how the rear end of your bike squats when you apply the rear brake. The geometry of the swingarm serves to pull the back of the bike down under braking-something you can use to your advantage.
Now add the front brake to the equation. You'll notice that the more front brake you use, the less effective-and harder to control-the rear brake is. It will lock up easier as weight transfer unloads the rear wheel. Some racers avoid using the rear binder on the track; they use so much front brake that the rear wheel is in the air, rendering the rear brake ineffective. In a basic stopping situation on the street, you want to use mostly the front brake with some rear. Using the rear brake, even slightly, will help to lower the center of gravity, adding stability to the situation and letting you brake harder in a panic stop. If the situation allows, touching the rear brake a half-second before the front will settle things more. Experiment to find what works best and is comfortable for you to execute with confidence.
In a sweeping turn, the rear...
In a sweeping turn, the rear brake can modulate corner speed to a much finer degree than using the front brake or closing and opening the throttle.
Now for the subtleties. Say you find yourself in a sweeping turn with a bit too much speed, or the corner tightens up slightly. Chopping the throttle and using the front brake will load up the front end, possibly overpowering tire traction and causing a crash. But in this situation, holding the throttle steady and applying a small amount of rear brake can scrub off just enough speed and actually help to tighten your line. The rear brake is much better at modulating your speed than the throttle and/or front brake; with the clutch out and the throttle steady, you'll find that you've got a surprising amount of control with the pedal alone. This is especially effective on a downhill turn, where keeping even slight maintenance throttle will have the bike accelerating. The rear brake will easily keep this in check while letting you stay on the throttle to avoid overloading the front tire.