( 9) Grips. The dual-compound grips have a softer
density for a more comfortable feel.
( 10) Weight. Overall, the 2015 KTM 450SXF is a little
over 1 pound lighter than the 2014 model (466 grams to
Q: HOW DO THE 4CS FORKS DIFFER FROM
THE PREVIOUS WP BLADDER FORKS?
A: The 4CS forks differs in five major ways from the
previous WP fork.
(1) The springs are on the top of the damping
system and can be removed without having to take the
fork completely apart.
( 2) The oil height isn’t measured in cubic centimeters
of oil, but instead by fork oil height (on a compressed
fork with the spring out).
( 3) All of the damping is housed in the lower fork-leg
cartridge, where the piston on the end of the cartridge
rod plunges through a sealed volume of oil, displacing it
out of the inner cartridge into an outer cartridge, where
it is bled off into a spring-loaded chamber that
compensates for the rod’s volume.
( 4) The compression adjuster is on the left fork cap,
while the rebound clicker is on the right cap. Where
the right and left fork legs differ is that the check valve
on the end of the cartridge rod is reversed in each
respective leg. That means that the right-side-up check
valve can close free bleed during the compression stroke
in the right fork leg, while the upside-down check valve
in the left leg shuts off bleed during the rebound stroke.
Other than the flip-flop, dual-duty, compression/rebound
check valve, both forks legs are identical.
( 5) Because the damping capabilities of the 4CS fork
are much greater than on the WP bladder fork, the 2015
KTM 450SXF uses 0.48 Nm fork springs instead of the
0.50 Nm springs from the 2014 model.
Q: WHAT IS THE PRACTICAL DOWNSIDE TO
THE 4CS FORK?
A: For racers who plan to send their 4CS forks out
to have them re-valved, the information base is very
shallow. Only 699 motocross versions of the 4CS forks
have ever been manufactured. That means that
your favorite suspension hop-up shop has very little
experience with these forks. You and a guinea pig will
have a lot in common until much later in the year.
Q: HOW GOOD ARE THE 2015 4CS FORKS?
A: At KTM there was an internal battle over the
use of the 4CS forks on the American-bound bikes.
WP wanted every bike to be equipped with the old-school bladder fork. KTM USA could see no marketing
advantage in continuing to use a fork that the vast
majority of American consumers do not like. So, KTM
USA and WP respectfully agreed to disagree and the
American branch set out on their own to fine-tune the
4CS fork for American consumers.
To our way of thinking, this was the smartest move
KTM USA could have done. Relying on WP’s expertise
had proven to be a major disaster over the years. Going
it alone was a brave move, but with risk comes reward.
So, how good are the 4CS forks? Every MXA test rider
thought that the 4CS fork was superior in every way to