Checking The Basic Setup Of The Telescopic Fork; Changing The Spring Preload On The Telescopic Fork (Sx Models); Changing The Spring Preload On The Telescopic Fork (Xc/Exc Models); Replacing Fork Springs - KTM 400 EXC Owner's Manual

MAINTENANCE WORK ON CHASSIS AND ENGINE
WP12187B06 250/400/450/525XC/EXC
WP12187B26
80/250
76/250
60 65 70 75
RIDERS WEIGHT INCLUSIVE GEARS IN KILOGRAM
WP14187B03
WP14187B05
4,4 N/mm
4,6 N/mm
4,2 N/mm
4,4 N/mm
60 65 70 75
RIDERS WEIGHT INCLUSIVE GEARS IN KILOGRAM
WP14187B06 250/400/450/525 XC/EXC
WP14187B29
4,2 N/mm
4,4 N/mm
4,0 N/mm
4,2 N/mm
60 65 70 75
RIDERS WEIGHT INCLUSIVE GEARS IN KILOGRAM
According to our experience, the damping rate of the compression stage can
remain unchanged. The damping rate of the rebound stage can be reduced
450/525 XC USA
by a few clicks for a softer spring or increased by a few clicks for a harder
spring.
84/250
80 85 90

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 (SX models)

The telescopic forks of the SX 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).
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.

Changing the spring preload on the telescopic fork (XC/EXC models)

250 SX-F
The telescopic forks for these models must be partly disassembled to adjust
450/525 SX
the spring preload (see WP manual). Pretension spacers are available in
heights of 1.5, 2.5 and 5 mm (see spare parts catalog). The fork springs may
4,6 N/mm
4,8 N/mm not be pretensioned by more than 20 mm.
The preload adjuster used in the SX models can easily be retrofitted for the
telescopic forks of the XC/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
80 85 90
degrees of pretension. Fork springs and pretension spacers should always stay
together.

Replacing fork springs

If you weigh less than 70 kg or more than 80 kg, you should install the respec-
450/525 XC USA
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
4,4 N/mm
embossed on the caps on the top of the telescopic fork.
4,6 N/mm
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.
80 85 90
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