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Adjustments for Competition 133
Rear Suspension Adjustments
3. Measure the loaded with rider dimension.
Remove the workstand. With two helpers
available, sit as far forward as possible on your
CRF’s seat, wearing your riding apparel.
Ask one helper to steady your CRF perfectly
upright so you can put both feet on the pegs.
Bounce your weight on the seat a couple of
times to help the suspension overcome any
situation and settle to a good reference point.
Ask the other helper to measure the loaded
with rider dimension.
Example:
4. Calculate the race sag dimension.
To do this, subtract the loaded with rider
dimension (step 3) from the unloaded
dimension (step 2).
Standard Race Sag: 4.1 in (105 mm)
Adjust spring pre-load as necessary to obtain
the desired handling results.
Decreasing the race sag dimension (example:
3.7 in, 95 mm) improves turning ability for
tight terrain at the cost of slightly reduced
straight line stability.
Increasing the race sag dimension (example:
4.5 in, 115 mm) may improve stability on
faster terrain with less turns, but will reduce
turning performance slightly and may upset the
balance between the front and rear suspension,
producing a harsher ride. This will happen if
the adjustment shifts the effective wheel travel
toward the more progressive end of its range.
Spring Rates
If you are lighter or heavier than the average rider
and cannot set the proper ride height without
altering the correct spring pre-load, consider an
aftermarket rear shock spring.
A spring that is too soft for your weight forces you
to add excessive spring pre-load to get the right
race sag and, as a result, the rear end of the
motorcycle is raised. This can cause the rear wheel
to unload too much in the air and top out as travel
rebounds. The rear end may top out from light
braking, or kick sideways over lips and square-
edged terrain. It may even top-out when you
dismount your CRF.
Because of the great absorption quality of the
shock bumper rubber, it may be difficult for you to
notice when your CRF’s suspension is bottoming.
Some riders may think the damping or perhaps the
leverage ratio is too harsh. In reality, the problem
is most likely insufficient spring pre-load or a
spring that is too soft. Either situation prevents
utilizing the full travel.
Keep in mind that a properly adjusted suspension
system may bottom slightly every few minutes at
full speed. Adjusting the suspension to avoid this
occasional bottoming may cost more in overall
suspension performance than it is worth.
A spring that is too stiff for your weight will not
allow the rear tire to hook up under acceleration
and will pass more bumps on to you.
Unloaded = 24.6 in (625 mm)
–Loaded = 20.7 in (525 mm)
Race Sag = 3.9 in (100 mm)
LOADED MEASUREMENT
(with rider)
EXAMPLE: 20.7 in (525 mm)
SEAT MOUNTING BOLT
CHAIN ADJUSTER LOCK NUT
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