Want to fiddle with the suspension on your track
bike? Firstly, check your tyre pressures and
make sure they're spot-on. Then identify whether
you want to alter your suspension at all. If
the bike feels fine, then don't touch it. But,
if you want to make some changes then this guide
should help you identify what adjusters do what
and how they affect your bike. The rule is to
set up your static sag and then make one adjustment
at a time, ride the bike and see what difference
it makes. Always make a note of the standard
settings, so you can easily go back to them
if you feel you're going in the wrong direction.
What is...?
Static sag: ...is the free play in your suspension
between maximum extension and a normal resting
position at a standstill. Lift the back of
the bike as far as it will go without the
rear wheel leaving the ground and measure
between the wheel spindle and a mark on top
of the tail unit. Then allow the bike to return
to its normal position and measure it again.
The difference is your static sag. Ideally
you want between 20-25mm. Repeat this process
with the forks to find your front sag. Remember,
more preload means less sag and vice versa.
Preload: ...is an amount of tension set in
a spring before a load is applied. It's the
most basic suspension adjustment found on
motorcycles.
Rebound damping: ...is what controls the
speed of your spring's rebound or bounce back
after being compressed. Without it, the bike
would bounce you out of the saddle over bumps,
while too much rebound and your springs won't
have time to recover between the bumps and
the bike will squat down.
Compression damping: ...controls the speed
at which the springs compress under load -
that means during braking, accelerating and
hitting bumps. Too much and it will feel harsh,
too little and your bike will see-saw from
one end to the other.
Where are the adjusters?
At the front...
...of the bike you have a pair of forks.
Preload adjusters sit at the top of the legs
and generally require a 14mm or 17mm spanner.
Adjustment is by turns and measured by rings
marked on the exposed part of the adjuster.
The more preload you wind in, the fewer rings
are left showing. Make sure you adjust them
together so the settings are the same. Front
rebound adjusters will be on the top of your
fork legs - they're the flat-headed screw
nipples that poke out of the preload adjusters.
These are measured by turns and many will
make an audible click when you turn them.
Compression damping is adjusted via screw
heads like rebound, but the adjusters themselves
are found at the base of the forks, by the
wheel spindle.
At the back...
...preload is put on at the back via a collar
normally on top of the spring on your shock
absorber. Sometimes the preload collar is
at the base of the shock so do check. Adjustments
are made with a C-spanner. Compression damping
can be altered by a flat-head screw adjuster
at the top of the shock body, while the rebound
adjuster can be found at the base of the shock,
this has another screw-type adjuster.
Please note: this general advice applies
to motorcycles being used on a closed circuit.
Before adjusting the suspension on your road
bike please contact your local dealer for
advice.
