KTM 250 XC-F - Manual (Page 30)

MAINTENANCE WORK ON CHASSIS AND ENGINE
»
ENGLISH
29
Checking the basic setup of the telescopic fork
The precise riding sag of the telescopic fork cannot be determined for
various reasons. Similar to the shock absorber, smaller deviations in your weight
can be compensated by adjusting the spring preload. However, if your
telescopic fork bumps frequently (hard end stop during compression), you should
install harder fork springs to avoid damaging the telescopic fork and frame.
Changing the spring preload on the telescopic fork
(XC, EXC SIXDAYS)
The telescopic forks of these models come with a preload adjuster for easy
adjustment of the spring preload. You can adjust the spring preload ± 9 mm
by turning the adjusting screws (basic position = middle position).
Turning in a clockwise direction will increase the prestress, turning in a coun-
terclockwise direction will decrease the prestress.
Changing the spring preload will not affect the rebound damping adjustment.
Generally, if the spring preload is higher, the rebound damping should also
be set higher.
NOTE:
Always turn the adjusting screws the same distance on both fork legs. Different
spring preloads on the fork legs will reduce the telescopic fork's response.
Replacing fork springs
If you weigh less than 75 kg or more than 85 kg, you should install the respec-
tive fork springs. The correct spring rate is shown in the illustrations. The stan-
dard spring is shown in bold print. The type number of the telescopic fork is
embossed on the caps on the top of the telescopic fork.
If you are uncertain which spring to use, contact your KTM workshop.
According to our experience, the damping rate of the compression stage can
remain unchanged. The damping rate of the rebound stage can be reduced
by a few clicks for a softer spring or increased by a few clicks for a harder
spring.
65
SPRING RA
TE
70 75 80 85 90 95
RIDERS WEIGHT INCLUSIVE GEARS IN KILOGRAM
4,6 N/mm
4,4 N/mm
4,2 N/mm
4,8 N/mm
4,6 N/mm
4,4 N/mm
4,4 N/mm
4,2 N/mm
4,0 N/mm
WP14187C29
WP14187C06, WP14187C28
WP14187C04
Changing the spring preload on the telescopic fork (XC-W/EXC)
The telescopic forks for these models must be partly disassembled to adjust
the spring preload (see WP manual). Pretension spacers are available in
heights of 1.5, 2.5, 5 and 10 mm (see spare parts catalog). The fork springs
may not be pretensioned by more than 20 mm.
The preload adjuster used in the XC models can easily be retrofitted for the
telescopic forks of the XC-W/EXC models.
NOTE:
WP precisely adjusts the spring pressure by inserting pretension spacers.
Fluctuations in production are compensated with pretension spacers in vari-
ous heights. This can cause the fork springs in the fork legs to have different
degrees of pretension. Fork springs and pretension spacers should always stay
together.