While it's true most of a motorcycle's stopping power is generated by the front brake, the rear binder can be used in subtle ways to make your riding smoother and safer. In certain situations, using the rear brake to scrub off speed-rather than chopping the throttle or applying the front brake-will have less of an effect on the chassis and keep you online in a turn rather than running wide. To use the rear brake properly, it must be adjusted correctly. The pedal should be a few millimeters below your foot when you're in a comfortable riding position; a maladjusted lever can force you to sit awkwardly or make it difficult to carefully actuate the brake.
During slow-speed maneuvering such as U-turns and lane splitting, the gyroscopic effect of your engine's spinning internals keeps your bike balanced. You can use this to your advantage by manipulating the rear brake and slipping the clutch slightly to keep some revs going. Try U-turns with different combinations of clutch, rear brake and throttle to find what works best for you and your bike. In general, just enough throttle and clutch slip is required to keep the chassis stable and moving, with speed modulated by the rear brake. Keep in mind this technique may result in more wear on brake pads and clutch plates, so they should be checked more frequently.
In downhill turns the rear brake can be used to avoid gaining too much speed once the throttle is open-especially in longer sweepers. As in a flat corner, crack the throttle open as soon as possible to unweight the front tire, and carefully utilize the rear brake to keep speed in check. Downhill turns are notorious for loading the front end and causing you to run wide, but keeping the throttle cracked open and carefully applying the rear brake will result in a more even weight distribution and keep you online. With some practice and experimentation, using these rear brake techniques will become routine and give you more confidence, smoothness and safety.
When entering a turn, leave the rear brake applied until after the front brake has been released and the bike is leaned over. This will stop the front end from rising the moment after the front brake is let off and before cornering forces act to keep the fork compressed. Once the throttle is cracked open, use the rear brake lightly to modulate your speed if you find yourself going a bit too fast. Closing the throttle will load the front end excessively and cause you to run wide, whereas applying the rear binder will actually tighten your line and pull you to the inside of the corner. Try to avoid using lots of gas and brake; you want just enough throttle to pick the revs up and keep weight off the front tire.