// MANUAL
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, progres-
sively 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 ying over the handlebars). 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” under braking, increasing the weight transfer (see
also Section 4.F). Practice braking and weight transfer techniques where there is no trac
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 bra-
ke 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.
D. SHIFTING GEARS
Your multi-speed bicycle will have a derailleur drivetrain (see 1. below), an internal gear hub
drivetrain (see 2. below) or, in some special cases, a combination of the two.
1. HOW A DERAILLEUR DRIVETRAIN WORKS
If your bicycle has a derailleur drivetrain, the gear-changing mechanism will have:
• a rear cassette or freewheel sprocket clustern
• a rear derailleur
• usually a front derailleur
• one or two shifters
• one, two or three front sprockets called chainrings
• a drive chain
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