51
b
c
d
a
9.2 Suspension Forks.
9.2.1 Adjusting the Spring Rate.
Most mountain, cruise and touring bikes are equipped with suspension
forks
(a)
. This feature gives you better control of your bicycle when rid-
ing cross-country or on rough road surfaces. It noticeably reduces the
strain on you and your bicycle caused by the mechanical shocks from
the terrain.
Suspension forks differ in their spring elements and in the way the
damping is realised. Suspension is provided by coil springs, special
types of plastic known as elastomers or sealed air compartments or
combinations of these options. The damping is usually done by oil or by
the self-damping properties of the elastomers.
For more information see the suspension glossary heading this
chapter.
In order to work optimally, the fork has to be adjusted to the weight of the
rider and the intended purpose. Be sure to have this adjustment carried
out by a bicycle specialist shop of your trust before delivery. With an air
sprung suspension fork you have to inflate it before your first ride. The
fork adjustment depends on the rider’s weight and the sitting posture.
Please bear in mind that the suspension fork should sag a little under the
rider’s weight. When the front wheel passes through a depression in the
ground, the spring extends and the suspension fork will smooth out the
uneven surface. If the selected air pressure or initial spring tension is too
high, this effect is lost because the wheel will already be fully extended.
This means the loss of an important feature affecting both safety and
comfort.
Cross-country and marathon racers usually run less sag than downhill-
ers or more comfort loving freeriders. For cross-country and marathon
riding the rear shock should yield by about 10-25 % of its total travel, for
enduro and freeriding by about 20-40 %.
Put a cable tie
(b)
onto the stanchion tube so that you can still slide it
easily along the tube’s exposed section.
To measure the maximum shock travel release all the air pressure from
the suspension fork. Then inflate the fork to the recommended air
pressure and measure the distance between the cable tie and the upper
edge of the lower tube.
