MXA’S KTM 350SXF
This is how we set up our 2017 KTM 350SXF for
racing. We offer it as a guide to help you find your own
WP AER FORK SETTINGS
The air pressure on every AER fork varies from KTM
model to KTM model. The 125SX and 150SX use 125 psi.
The 250SX has 148 psi. The 250SXF and 350SXF come
with 154 psi, and the 450SXF is set at 156 psi. But, you
aren’t locked into those numbers. Most MXA test riders
ran lower air pressures in the 350SXF forks. How do we
arrive at the proper air pressure? With a two-pronged
approach. First, we start with the OEM recommended
air pressure and note how high the forks ride in their
stroke and how much travel they get over the jumps
(with a zip-tie on one fork leg). With the stock air pressure, the AER forks typically ride high in their stroke
and come up about 3 inches short of bottoming. Then
we lower the air pressure in 2-psi increments. How do
we know when we have the proper pressure? First,
the forks don’t feel like they are dropping excessively
into their stroke, and second, they are getting almost
full travel. For hard-core racing, we recommend this
fork setup on the 2017 KTM 350SXF (stock specs are in
Spring rate: 140 psi ( 154 psi)
Compression: 20 clicks out ( 12 clicks out)
Rebound: 15 clicks out ( 12 clicks out)
Fork-leg height: Third line
Notes: Slower or lighter riders might have to lower
the oil height in the damping leg by 10mm or more to
get full travel. Additionally, pay attention to extreme
temperature changes, you may have to change the
AER’s air pressure as it gets hotter later in the day.
However, we do bleed the outer chamber constantly,
which is accessed via a 10mm hex head or #20 Torx.
Even if you own a #20 Torx, don’t use it because it
strips out easily.
WP SHOCK SETTINGS
Last year the KTM 350SXF came with a very stiff 48
N/m shock spring. Many riders had trouble getting any
preload on the shock spring. We swapped all of our 48
N/m springs for the lighter 45 N/m spring from the
250SXF. For 2017 KTM is lowering all of its motocross
bike spring rates, which means that the 2017 350SXF
will have a 42 N/m spring stock. If you are around 180
pounds, you might want to go to a 45 N/m spring. If
you are over 200 pounds, you will probably want to
return to the 48 N/m spring. For hard-core racing, we
recommend this shock setup for the 2017 KTM 350SXF
(stock specs are in parentheses):
Spring rate: 42 N/m
Race sag: 105mm (110mm)
Hi-compression: 1-3/4 turns out ( 2 turns out)
Lo-compression: 15 clicks out
Rebound: 10 clicks out ( 15 clicks out)
Notes: We turned the high-speed compression damping in a little to lessen G-outs and ran a touch more
rebound than the recommended setting. Additionally, we
set the sag at 105mm instead of the WP-recommended
Step number one in getting the most out of your 2017 350SXF
is to gear it down at least one tooth.
tie-downs onto your handlebars that they don’t crimp the
L-bend tube coming out of the front brake’s master cylinder. We would prefer more room between the brake line
and the bars to lessen the chance of damage.
Q: WHAT DID WE LIKE?
A: The like list:
(1) Handling. You don’t have to point it where you
want it to go; you just have to think it.
( 2) Hydraulic clutch. This clutch is stout enough to
last a full race season without being touched.
( 3) Weight. You have to be impressed by the 221-pound
weight. This is an impossible dream achieved with a battery and electric starter.
( 4) Powerband. Even though the MXA wrecking crew
thinks that a 375cc, 380cc or 400cc displacement would
come closer to fulfilling the dream of a mid-size Open-class
bike, the 350SXF is the ultimate expression of a 250 on
( 5) Tires. We like the Dunlop MX3S intermediate tires,
but be forewarned that if you run them on hard-pack dirt,
the side knobs will rip off the front tire.
( 6) Hour meter. Kudos to KTM for putting an hour
meter on its bikes at the factory—and saving us the trouble.
Q: WHAT DO WE REALLY THINK?
A: Pinch yourself. Not just because the 2017 KTM
350SXF suddenly has forks that work, but because KTM
was brave enough to build something unique, with a dif-
ferent displacement, electric starting, hydraulic clutch, the
world’s simplest air filter, awesome brakes, superb han-
dling and value in every part. This is a dream bike for a
large portion of motocross riders. And if you don’t believe
it, try to buy a Honda CRF350, Yamaha YZ350F, Suzuki
RM-Z350 or Kawasaki KX350F. Dream on.