Owner`s manual

18
Cervélo Owner’s Manual
make sure that you have maximum friction available, keep your
wheel rims and brake pads 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).
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. 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.
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 to begin with.
D. Shifting Gears
Your multi-speed bicycle will have a derailleur drivetrain.
1. How a derailleur drivetrain works
The parts of the gear-changing mechanism include:
• a rear cassette or freewheel sprocket cluster
• a rear derailleur
• usually a front derailleur
• one or two shifters
• one, two or three front sprockets called chainrings
• a drive chain
a. Shifting Gears