Rim Brakes; Racing And Side-Pull Brakes - Scott TIME TRIAL MACHINE Owner's Manual

RIM BRAKES

Racing and side-pull brakes

Operation and wear
Actuating the levers on the handlebars (a) and cables (b) causes a brake pad
to be pressed against a brake surface. The ensuing friction slows down the
wheel. If water, dirt or oil come into contact with one of the braking surfaces,
this changes the coefficient of friction and deceleration is reduced. This is why
brakes respond with a slight delay and less powerfully in wet weather.
In order to maintain their effectiveness, brakes need to be checked and read-
justed regularly.
The friction generated by braking causes wear to the brake pads as well as to
the rims. Frequent rides in the rain and dirt and over hilly terrain can accelerate
wear on both braking surfaces. Some rims are provided with wear indicators,
e.g. grooves or circular indentations. If the rim is worn down to the point where
the grooves or indentations are no longer visible, they need to be replaced.
Once the abrasion of the rim has reached a certain critical point, the rim may
break under the tyre pressure. This can make the wheel jam or the inner tube
burst, both of which can cause an accident. Risk of falling!
Functional check
Test the brakes in stationary by firmly pulling the brake levers towards the
handlebars. The brake pads of rim brakes must hit the rim evenly with their
entire surface without touching the tyre during braking, in open condition or in
between.
Check whether the brake pads are accurately aligned with the rims and still suf-
ficiently thick. You can judge the wear of the brake pads by the appearance of
grooves. If the pads are worn down to the bottom of the grooves (c), it is time to
replace them. Be sure to observe the appropriate instructions of the respective
manufacturer.
The brake levers must always remain clear of the handlebars. You should not
even be able to pull them all the way to the handlebars in the event of an emer-
gency stop. If this is the case, however, observe the following chapter "Synchro-
nising and readjusting".
a b c
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OWNER'S MANUAL 2021 | ROAD BIKE