KTM XC - Manual (Page 19)

ENGLISH
18
MAINTENANCE WORK ON CHASSIS AND ENGINE
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Basic suspension setup for the weight of the driver
To achieve maximum handling performance and to prevent the fork, shock
absorber, swing arm and frame from being damaged, the basic setup of the
suspension components must be suitable for your child's weight. At delivery,
the fork and shock absorber are set to accommodate a driver weighing between
45 and 55 kg (wearing full protective clothing). If your child's weight exceeds
or falls short of this range, you will need to adjust the spring components accord-
ingly.
Minor deviations in weight can be compensated by adjusting the spring pre-
load on the shock absorber. Other springs must be mounted on the fork and
shock absorber for larger deviations.
Checking the shock absorber and spring
You can establish whether or not the shock absorber spring is suitable for your
child's weight by checking the riding sag. The static sag must be correctly
adjusted before the riding sag can be determined.
Determining the static sag of the shock absorber
The static sag should be between 30 and 35 mm. Larger deviations can strongly
influence the motorcycle's performance.
Procedure:
– Jack up the motorcycle until the rear wheel no longer touches the ground.
– Measure the vertical distance between the rear wheel axle and a fixed point
(e.g. a mark on the side cover) and write it down as dimension A.
– Place the motorcycle on the ground again.
– Ask a helper to hold the motorcycle in vertical position.
– Measure the distance between the rear axle and the fixed point again to
establish dimension B.
– The static sag is the difference between dimensions A and B.
EXAMPLE:
Motorcycle jacked up (dimension A) . . . . . . . . . . . . . . . . . . . . . .600 mm
Motorcycle on ground, unloaded (dimension B) . . . . . . . . . . . .– 565 mm
Static sag . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35 mm
If the static sag is lower, the spring preload of the shock absorber must be
increased, if the static sag is reduced, the spring preload must be higher. See
chapter "Changing the spring preload of the shock absorber."
Determining the riding sag of the shock absorber
– Have a helper hold the motorcycle. Your child should sit on the bike in a
normal seating position (feet on the footrests) and bounce up and down
a few times to allow the rear wheel suspension to become level.
– With your child on the bike, measure the distance between the same two
points and write it down as dimension C.
– The riding sag is the difference between dimensions A and C.
EXAMPLE:
Motorcycle jacked up (dimension A) . . . . . . . . . . . . . . . . . . . . . .600 mm
Motorcycle on ground, loaded (dimension C) . . . . . . . . . . . . . .– 500 mm
Riding sag . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .100 mm
The riding sag should lie between 95 and 105 mm.
If the riding sag is less than 95 mm, the spring is too hard (the spring rate is
too high). If the riding sag is more than 105 mm, the spring is too soft (the
spring rate is too low).
C
B
A