Suspension Adjustment; Race Sag - Honda CR250R 2004 Owner's Manual

6. SUSPENSION ADJUSTMENT

RACE SAG

Standard Race sag: 3.9 in (100 mm)
There are a series of adjustments that should be per-
formed on a factory-new CR; once after the pre-ride
inspection, then again after initial break-in. First and
foremost among these is the rear suspension Race Sag
adjustment.
First, A Common Mistake
Due to the great absorption quality of the shock bump
rubber, it is difficult for all but a few riders to notice
when their CR's suspension is bottoming out. Many
riders think the damping or perhaps the leverage ratio
is too harsh. In reality, they're running too little preload
or a spring that's too soft and using only the last third
of the stroke.
Setting your CR's shock spring preload/Race Sag di-
mension according to the guidelines here will ensure
correct adjustment and spring selection.
Shock Spring Preload And Race Sag Adjustment
The adjustment procedure that follows establishes the
correct starting point for any suspension tuning. It
guides you to both proper spring preload adjustment
and spring selection for your specific needs. Damping
adjustments are described elsewhere in this manual.
The first step toward determining proper suspension
adjustment is to set the rear spring preload so that the
proper ride height, or Race Sag dimension, is achieved.
For this adjustment procedure, the bike should be
brought to normal racing weight—correct fuel, trans-
mission oil and coolant levels.
First measure the Unloaded dimension when your CR
is supported by a workstand without the left side cover
and the rear wheel is off the ground. Measure the
distance from the center of the rear fender mounting
bolt to the center of the chain adjuster lock nut as
illustrated here.
52
UNLOADED MEASUREMENT
(without rider)
EXAMPLE: 23.6 in (600 mm)
Next measure the Loaded dimension with the rider
aboard, wearing all normal riding gear. Ask a buddy to
steady the bike perfectly upright so you can put both
feet on the pegs. You'll need another helper to
measure. Bounce your weight on the seat a couple of
times to help the suspension overcome any stiction
and settle to a good reference point.
LOADED
(with rider)
EXAMPLE: 19.7 in (500 mm)
EXAMPLE:
UNLOADED = 23.6 in (600 mm)
– LOADED = 19.7 in (500 mm)
RACE SAG = 3.9 in (100 mm)
The Race Sag dimension is the difference between the
Unloaded and the Loaded measurements.
Standard Race Sag: 3.9 in (100 mm)
Adjust spring preload as necessary to obtain the cor-
rect handling results.
A Race Sag setting of 3.5 in (90 mm) improves turning
ability for tight tracks at the cost of slightly reduced
straight line stability. Setting this dimension 4.3 in
(110 mm) improves stability on faster tracks with less
turns, but reduces turning performance slightly.
Determining If You Have The Correct Spring
Next you must compare the rear suspension sag under
the weight of the sprung portion of the bike alone
(without rider's weight) to the Unloaded dimension.
BIKE LOADED
(without rider)
EXAMPLE: 21.6 in (550 mm)
EXAMPLE:
UNLOADED = 23.6 in (600 mm)
– LOADED = 21.6 in (550 mm)
SAG = 2.0 in (50 mm)
(WITHOUT RIDER)