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Rear Suspension Race Sag
Setting the proper race sag (ride height) is very
important for competition use.
Race sag refers to the amount of rear wheel
travel used by your CR at rest, ready to ride, with
you on the seat. As a general rule of thumb, the
race sag dimension should be about one-third of
the maximum travel.
On your CR, ride height is changed by adjusting
the rear suspension spring pre-load.
Spring Pre-load & Race Sag Adjustment
The following adjustment procedure establishes
the correct starting point for any suspension
tuning — the proper rear spring pre-load
adjustment for your specific needs.
Your CR should be at normal racing weight,
including fuel and transmission oil. You should
be wearing all your normal protective apparel.
You will need two helpers.
To calculate the proper adjustment, it is necessary
to measure between two fixed points — from the
top of the most rearward point of the subframe
down to the machined edge at the rear of the
swingarm, as illustrated — for three different
situations:
unloaded: motorcycle on optional workstand with
rear suspension fully extended, no rider.
loaded with rider: motorcycle on ground, with
rider.
loaded without rider: motorcycle on ground,
without rider
1. Support your CR on a workstand with the rear
wheel off the ground.
2. Measure the unloaded dimension.
UNLOADED MEASUREMENT
(on workstand, without rider)
EXAMPLE: 23.6 in (600 mm)
3. Measure the loaded with rider dimension.
Remove the workstand. With two helpers
available, sit as far forward as possible on
your CR's seat, wearing your riding apparel.
Ask one helper to steady your CR 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
stiction and settle to a good reference point.
Ask the other helper to measure the loaded
with rider dimension.
LOADED MEASUREMENT
(on ground, with rider)
EXAMPLE: 19.7 in (500 mm)
Race Sag Calculation:
unloaded
23.6 in (600 mm)
—loaded with rider
19.7 in (500 mm)
Race Sag
3.9 in (100 mm)
Rear Suspension Adjustments
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: 3.9 in (100 mm)
Adjust spring pre-load as necessary to obtain the
desired handling results.
Decreasing the race sag dimension (example: 3.5
in, 90 mm) improves turning ability for tight
terrain at the cost of slightly reduced straight line
stability.
Increasing the race sag dimension (example: 4.3
in, 110 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.
5. Measure the loaded without rider dimension.
Do this with your CR set at the standard race
sag.
LOADED MEASUREMENT
(on ground, without rider)
EXAMPLE: 21.6 in (550 mm)
Free Sag Calculation:
unloaded
23.6 in (600 mm)
—loaded without rider 21.6 in (550 mm)
Free Sag
2.0 in (50 mm)
Adjustments for Competition
(cont'd)
97
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