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G
G
a
G
Synchronising and Readjusting
Almost all brake designs have a bolt located next to one or both brake
callipers to adjust the initial spring tension. Turn the bolt slowly and
watch how the gap changes between the brake pads and the rim (c).
Adjust the spring in a way that with an unapplied brake the gaps are
equal on either side and the brake pads touch the rim simultaneously
during braking.
b
The position of the brake lever where the brake starts to act, also re-
ferred to as the pressure point, can be adjusted to the size of the hand
as well as to individual convenience by readjusting the brake cable.
Make absolutely sure you cannot pull the brake lever all the way to the
handlebar grip. With an unapplied brake the brake pads should not
be too close to the rim sides, otherwise they could drag along the rim
during riding. Before doing this adjustment, observe the notes in the
chapter "adjusting the brake lever reach".
To readjust the brakes, unscrew the knurled lock ring located at the
c
point where the brake cable enters the brake lever on the handlebars.
Unscrew the knurled, slotted adjusting bolt by a few turns. This reduces
the free travel of the brake lever. Keeping the adjusting bolt firm, tighten
the lock ring against the brake lever unit. This prevents the adjusting
bolt from coming loose by itself. Ensure that the slot of the bolt faces
neither forward nor upward, as this would permit water or dirt to enter
more easily.
G
d
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Brake cables
(a)
which are damaged, e.g. frayed, must be
replaced immediately, as they can otherwise fail in a critical
moment, possibly causing a crash!
Adjusting the position of the brake pads relative to the rims
(b)
requires a considerable degree of skill. Replacing and
adjusting the brake pads is a job best left to your WHEELER
bicycle dealer.
Have your rims regularly inspected and measured by your
WHEELER bicycle dealer.
Always test the brakes' function when stationary after ad-
justing them (d), making sure the brake pads engage fully
with the rim when you pull them hard.
Hydraulic Rim Brakes
operation and Wear
Common hydraulic rim brakes
(e)
consist of two brake assemblies
that are mounted on the left and right side of the rim and connected
by an assembly plate and, if necessary by a brake booster. Actuating
the brake lever compresses the hydraulic pistons through oil pressure,
pushing the brake pads against the rims.
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, it needs 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! danger of an accident!
Keep the hydraulic brake assemblies, especially the brake pad area,
clean (g), as dirt can prevent the pads from travelling back in their rest
position. Regularly check the lines and connections for leaks.
G
Loose connections or leaky brake lines can drastically im-
pair braking power. If you find leaks in the brake system or
kinks in the lines, contact your WHEELER bicycle dealer.
risk of accidents!
Functional Check
Check whether the brake pads are accurately aligned with the rims and
still sufficiently 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, it is time to replace them. Be sure to observe the according
instructions of the respective manufacturer.
See your WHEELER bicycle dealer and ask them to examine the remain-
ing thickness of the rims when you have worn through your second
set of brake pads at the latest. He has special measuring devices to
determine the remaining thickness of the rims (h).
e
(f)
f
f
g
h
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