A motorcycle's brakes are both its most powerful component and the most difficult to master. In nearly a decade of teaching high-performance riding on racetracks all over the United States, Germany, France and Japan, I can say with confidence that even those riders serious enough to go to high-end schools have difficulty getting much more than 50 percent of the braking potential from modern sportbikes.
As impressive as today's 1000cc sportbikes are, accelerating to nearly 150 mph in a quarter-mile (1320 feet), their brakes can haul them back to a stop in about half that distance. Most riders can get better than 90 percent of the engine's potential by simply launching well and twisting a throttle, but achieving maximum braking is a different matter altogether.
While most riders assume effective braking involves more bravery than brains (some like to cite Kevin Schwantz's famous quote: "Wait 'til you see God-then brake!"), it's better to think about what specifically you hope to accomplish with braking and how to best achieve that goal. The first basic premise is that the whole purpose of braking is to arrive at a particular spot at the desired speed; whether it's stopping at a stop sign or arriving at a 45-mph corner entrance at 45 mph. In high-speed riding, too much emphasis is put on where we begin to apply the brakes, with the misconception that the later we begin braking the better. Consequently, not enough thought is put into arriving at the corner entrance fully prepared, at your desired speed and in the correct gear. It's all too common to see a panicked rider fully engaged in heavy braking while hastily stomping the last downshifts as he blows past the turn-in point. Get your heavy braking and downshifts done early.
It's also important to understand weight transfer, and why our bikes are able to literally stand on their nose under heavy braking without losing front-tire traction. Under acceleration, weight is transferred to the rear tire, and the rear suspension helps gain more rear-tire traction by compressing slightly and allowing more of this weight transfer to occur. Under braking, the weight obviously transfers to the front end, and here the front suspension aids front-tire traction by compressing and concentrating more weight onto the tire contact patch. To get the traction we need for maximum braking requires smoothly rolling off the throttle and then smoothly applying the front brake. If you suddenly chop the throttle and grab the front brake lever in a panicked death grip, so much weight is immediately transferred to the front that the fork actually bottoms out, which not only compromises chassis control, but also front-tire traction. When the front fork bottoms out under braking, so much weight transfer occurs that the rear tire lifts off the ground, which can quickly lead to stability problems, and without any fork travel to absorb bumps while braking, it's very easy for the contact patch to lose grip. Being smooth is crucial to the bike's stability, the rider's confidence and the feeling of control; it's nearly impossible to brake effectively without confidence and control.
You should always practice maximum braking in controlled conditions-read: racetrack-where you can safely explore your limits. In this situation, many riders (myself included) ignore the rear brake entirely. Others choose to use the rear brake to balance the chassis. There are valid reasons for both techniques, so try them both to see which works best for you. Remember, however, that a sportbike is able to transfer all its weight to the front during braking, so extreme care must be taken when using the rear brake, to avoid wheel lockup.