Shifting Gears - Giant momentum Anleitung

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. 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 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.
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 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
There are several different types and styles of shifting controls: levers, twist grips, triggers, combination
shift/brake controls and push-buttons. Ask your dealer to explain the type of shifting controls that are on your
bike, and to show you how they work.
The vocabulary of shifting can be pretty confusing. A downshift is a shift to a "lower" or "slower" gear, one
which is easier to pedal. An upshift is a shift to a "higher" or "faster", harder to pedal gear. What's confusing is
that what's happening at the front derailleur is the opposite of what's happening at the rear derailleur (for details,
read the instructions on Shifting the Rear Derailleur and Shifting the Front Derailleur below). For example, you
can select a gear which will make pedaling easier on a hill (make a downshift) in one of two ways: shift the chain
down the gear "steps" to a smaller gear at the front, or up the gear "steps" to a larger gear at the rear. So, at the
rear gear cluster, what is called a downshift looks like an upshift. The way to keep things straight is to remember
that shifting the chain in towards the centerline of the bike is for accelerating and climbing and is called a
downshift. Moving the chain out or away from the centerline of the bike is for speed and is called an upshift.
Whether upshifting or downshifting, the bicycle derailleur system design requires that the drive chain be
moving forward and be under at least some tension. A derailleur will shift only if you are pedaling forward.
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