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Braking Effectively - Riding Skills Series

Being Better On The Brakes


writer: Lance Holst
photographer: Brian J. Nelson




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.

While practicing braking technique, begin with early braking points to
perfect the sequence without the stress of a fast-approaching corner.
Initially, smooth is slow, but as you master the technique, you'll find you
will be able to remain smooth while executing these inputs in an ever-shorter
period of time. Keep in mind, however, that doing it quickly is
optional-doing it smoothly is not.

Once the weight is transferred forward and the fork is compressed, it's time
to transition to maximum braking, really squeezing the front brake lever
(again, smoothly). Build up the level of lever pressure incrementally over
many, many sessions, and you should feel the limits of front-tire traction
and the rear tire lifting. Don't rush to find the limit; this is delicate
business and the price of exceeding the limit is dear indeed. To best judge
your corner-entrance speed, try to get your heaviest braking done early,
allowing you to release the brakes smoothly over the end of the braking zone,
transitioning from near-maximum fork compression to perhaps 50-70 percent of
its stroke, where fork travel usually ends up under maximum cornering force.

I confirmed these figures by calling Yoshimura Suzuki crew chief Tom
Houseworth, the man leading the group responsible for current AMA Superbike
Champion Ben Spies' GSX-R1000. When asked where in the stroke the front
suspension is during maximum cornering, Houseworth called up Spies' data from
a recent test at Fontana on his computer. "In Turn Five-the double left-once
he's off the brake, and in the three-tenths of a second before he's back on
the throttle, Ben's at 84 out of 120mm of stroke, so yeah, 70 percent." Most
of us don't corner as aggressively as Spies, so figure something nearer 50 or
60 percent stroke.

When I taught at the Kevin Schwantz Suzuki School, fellow instructor and
three-time AMA National Champion Jamie James said it best with the fewest
words: "Release the front brake even slower than you squeeze it on." This
allows the weight to transfer more evenly front-to-rear, to prevent the front
suspension from rebounding (springing back) too quickly and upsetting the
chassis as you're entering the corner. At the same time, you need to be
careful not to overload the front contact patch with too much braking as you
lean into the corner, causing the front tire to slide or push, which to the
vast majority of mortals is quickly followed by dragging your elbow and then
helmet in rapid succession.

In my experience, more crashes are caused by trailing the brakes too hard and
deeply into the corner than any other method of losing traction, so beware.
Front-tire traction is never more critical than while turning into a corner
with the throttle off and the front brake on, so this balancing act of
braking force versus cornering force is best done with delicate care. That
said, Houseworth's data revealed that Spies trails the brakes all the way to
the corner's apex (with the fork at or near maximum compression). Evidently,
that's what it takes to beat six-time AMA Superbike Champion Mat Mladin. Only
two men have beaten Mladin in eight years-Spies and current MotoGP World
Champion Nicky Hayden-so for the rest of us, it's prudent to not push the
limits of trail-braking.

Now that we've gone over how to brake effectively, it's important to remember
that even at their best, braking distances increase exponentially (the
mathematics of which, according to my physics authority and riding buddy Brad
Hancock, is that kinetic energy equals one-half mass times velocity squared),
not linearly. In other words, while an expert rider can bring a good bike
from 30 mph to a stop in about 30 feet, at double that speed, 60 mph, it
takes 120 feet. At 120 mph, figure close to 480 feet of stopping distance and
so on. This is the fact that catches many riders out. I seldom tell anyone
how fast is safe to ride, but I absolutely believe that whatever speed you
choose to ride, be damn sure you first have plenty of experience stopping and
steering from that speed.