MXA’S KTM 125SX
This is how we set up our 2016 KTM 125SX for
racing. We offer it as a guide to help you find your
own sweet spot.
WP FORK SETTINGS
It was easy to find a happy medium for just about
any size rider with the updated WP 4CS forks. We had
riders from 135 pounds to over 200 pounds who found
a setting that worked for them. Raising the forks in
the clamps 4mm above the second line improved
cornering and provided a more balanced feel. The
spring rate is softer than last year’s, going from 4. 4
N/m to 4. 2 N/m. The following settings are what
worked best for a 170-pound Novice. For heavier or
lighter riders, we adjusted the compression accordingly
and left the rebound alone. Here is what we ran (stock
Spring rate: 4. 2 N/m
Compression: 8 clicks out ( 15 clicks out)
Rebound: 12 clicks out ( 15 clicks out)
Fork-leg height: 9mm up (5mm)
Notes: The fork spring rate is light because of the
target weight of the typical 125/150 rider. If you are
heavier, don’t worry, the WP suspension has enough
adjustment to accommodate you. Lighter riders can
turn the compression clicker out to get the feel
WP SHOCK SETTINGS
KTM’s overall plan with the chassis, along with
the updated WP shock and rising-rate linkage, was to
soften the shock spring rates considerably (going
lighter helps the KTM). For hard-core racing, we
recommend this shock setup for the 2016 KTM 125SX
(stock specs are in parentheses):
Spring rate: 42 N/mm
Race sag: 102mm
Hi-compression: 2 turns out
Lo-compression: 10 out ( 15 out)
Rebound: 11 out ( 15 out)
Notes: We run less race sag than KTM’s
recommended 110mm. We feel the bike rides too low
and sacrifices cornering at 110mm, so we raise the
sag and lower the forks for better balance and
KEIHIN PWK 38S JETTING SPECS
Here’s what we ran in our 38mm PWK (stock
settings are in parentheses).
Main jet: 182
Needle: NIEF needle
Clip: 2nd clip from top
Air screw: 2 turns out (1 turn) . ;
Q: WHAT DID WE HATE?
A: The hate list:
(1) Gas cap vent hose. KTM’s vent hose gets
twisted in a knot when you take it on and off to fill the
tank. Plus, the cap tends to stick.
( 2) Sprocket bolts. Watch them like a hawk, as
they come loose quickly.
( 3) Gearing. We found a perkier, easier-to-ride
powerband by going taller on the gearing.
( 4) Grips. All the 2016 four-stroke KTM SXF models
got upgraded to ODI lock-on grips. And guess what? We
love them. The KTM 125SX has last year’s orange and
black grips. We don’t love them.
( 5) Black frame. We don’t hate the black frame color;
we just hate that KTM changed it from orange to black.
( 6) Shift lever. Our shift lever spring broke.
( 7) Tires. Although we don’t really hate the Dunlop
MX32 front tire, we do need to warn riders that if they
push the MX32s across hard-terrain dirt, they need to
keep a close eye on the side knobs. They will tear off.
Q: WHAT DID WE LIKE?
A: The like list:
(1) Weight. The 2016 KTM 125SX is 8-1/2 pounds
lighter than the 2015 model and 20 pounds lighter than
the lightest 250 four-stroke.
( 2) Brakes. They are not as strong as last year’s, but
they are still the best in the class.
( 3) Hydraulic clutch. KTM’s self-adjusting clutch is
ahead of its time.
( 4) Airbox. We don’t think changing an air filter
could get any simpler.
( 5) Sag line. It helps you adjust the sag with ease.
( 6) Easy-adjust forks. We love that you can pull off
the side of the track and adjust the forks without tools.
( 7) Suspension. These are not SSS components, but
they are a big step in the right direction.
( 8) Fuel. Our 2016 KTM 125SX ran well on 91-octane
pump gas, but we always added a dash of VP Racing
C12 as a precaution.
( 9) Tires. The 125SX comes with our favorite tires—
Dunlop Geomax MX32s.
Q: WHAT DO WE REALLY THINK?
A: The Japanese manufacturers need to step up
to the plate and start producing two-strokes again. The
125cc has always been the stepping stone bike for
riders coming off of 85cc machines and the entry point
for neophyte riders. Without a vibrant 125cc class, the
sport is going to have trouble filling the newbie ranks.
Forgiving. You can even put the air filter in upside down.
With that said, the 2016 KTM 125SX is superior to the
2015 model. We loved every second of riding
this machine. The powerband is incredible and the
WP suspension is surprisingly good. There is not much
to complain about.