B: How Brakes Work - Schwinn Hybrid Owner's Manual

4 Tech

3.B: How Brakes Work

The braking action of a bicycle is a function of the friction
between the braking surfaces. To make sure that you have
maximum friction available, keep your wheel rims and brake
pads or the disk rotor and caliper clean and free of dirt,
lubricants, waxes or polishes.
Brakes are designed to control your speed, not just to stop the
bike. Maximum braking force for each wheel occurs at the point
just before the wheel "locks up" (stops rotating) and starts to
skid. Once the tire skids, you actually lose most of your
stopping force and all directional control. You need to practice
slowing and stopping smoothly without locking up a wheel. The
technique is called progressive brake modulation. Instead of
jerking the brake lever to the position where you think you'll
generate appropriate braking force, squeeze the lever,
progressively increasing the braking force. If you feel the wheel
begin to lock up, release pressure just a little to keep the wheel
rotating just short of lockup. It's important to develop a feel for
the amount of brake lever pressure required for each wheel at
different speeds and on different surfaces. To better
understand this, experiment a little by walking your bike and
applying different amounts of pressure to each brake lever,
until the wheel locks.
When you apply one or both brakes, the bike begins to slow,
but your body wants to continue at the speed at which it was
going. This causes a transfer of weight to the front wheel
(or, under heavy braking, around the front wheel hub, which
could send you flying over the handlebars).
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A wheel with more weight on it will accept greater brake pressure
before lockup; a wheel with less weight will lock up with less brake
pressure.
So, as you apply brakes and your weight is transferred forward, you
need to shift your body toward the rear of the bike, to transfer
weight back on to the rear wheel; and at the same time, you need
to both decrease rear braking and increase front braking force.
This is even more important on descents, because descents shift
weight forward.
Two keys to effective speed control and safe stopping are
controlling wheel lockup and weight transfer. This weight transfer
is even more pronounced if your bike has a front suspension fork.
Front suspension "dips/compresses/dives" under braking,
increasing the weight transfer (see also Section 4.F). Practice
braking and weight transfer techniques where there is no traffic or
other hazards and distractions.
Everything changes when you ride on loose surfaces or in wet
weather. It will take longer to stop on loose surfaces or in wet
weather. Tire adhesion is reduced, so the wheels have less
cornering and braking traction and can lock up with less brake
force. Moisture or dirt on the brake pads reduces their ability to
grip. The way to maintain control on loose or wet surfaces is to go
more slowly.