Kawasaki engineers are busy little bees. Each and
every year they make lots of changes. Unfortunately,
they have never been very good at making much of a
difference when it comes to handling, weight, clutch,
shifting or ergonomics. Thankfully, the KX450F engine
doesn’t need much improvement because it is already so
good. The big news for 2015 is the addition of traction
control (or at least the first time that traction control has
been turned on inside the ECU for people not named
Villopoto). Is it a better KX450F than what came before?
Our answer is a lukewarm yes.
Traction control. What a happy circumstance that
the AMA changed its traction-control rules in time for the
2015 KX450F to come with it—or was that vice versa? If
it is working right, you will never notice it.
Launch Control. Use it or not. We run it on concrete
and hardpack starts, but not on loam.
Rear axle nut. Thank you, Kawasaki, for getting rid
of that stupid cotter pin.
SFF Air forks. Hey, we may doubt the wisdom of
spec’ing them, but they are 2 pounds lighter and can be
made to work adequately with time and effort—a lot of
effort. It doesn’t help that the stock settings are so far off
Oversize brake. Kawasaki added a 270mm front-
brake rotor for 2015. Finally, it stops as good as it goes.
Power. It’s a little mellower than the 2014 model, but
that’s not necessarily a bad thing.
Girth. Too big, too tall and too heavy.
Clutch. The stock KX450F clutch is marginal. If you
are a clutch abuser, you will eat this clutch in short
Sound. This bike makes an ear-piercing 120 dB on
the AMA two-meter-max test. It does, however, pass the
Amateur-required SAE 94 dB test.
Rear brake pedal. Old-school racers will have to
hacksaw off some of the plunger’s threaded rod to lower
the brake pedal enough.
Ignition. We had some issues with the engine cutting
Handling. This is an upright bike that doesn’t like to
be leaned over unless there is something to lean against.
It requires the most steering input of any 450 race bike.
It doesn’t have bad handling, just nothing to write home
BEST SUSPENSION SETTINGS?
Forks. These are MXA’s recommended 2015 Kawasaki
KX450F fork settings (stock settings are in parentheses).
Inner spring rate: 170 psi ( 145 psi)
Outer spring rate: 15 psi ( 7. 5 psi)
Balance spring rate: 170 psi ( 135 psi)
Oil height: 340cc (left leg), 100cc (inner chamber),
300cc (outer chamber), 10cc (balance chamber)
Compression: 20 clicks out ( 5 clicks out)
Rebound: 20 clicks out ( 13 clicks out)
Fork leg height: 5mm up
Notes: Start with our settings and change the air
pressure in the inner chamber up or down, depending on
your needs in 2 psi increments, until you find the most
supple feel. Then play with the outer chamber pressure.
Shock. These are MXA’s recommended 2015
Kawasaki KX450F shock settings (stock settings are in
Spring rate: 5. 5 kg/mm
Hi-compression: 2-1/4 turns out ( 2 turns out)
Lo-compression: 16 clicks out ( 12 clicks out)
Rebound: 11 clicks out ( 10 clicks out)
Race sag: 104mm
Notes: The shock did not blow through the stroke
as easily as last year, which is a big plus. The rear end
worked very well under braking in chop and square-edged bumps, and wallowing was minimal.
WHAT DID WE CHANGE?
Here is the short list of things the MXA wrecking crew
changed on the 2015 KX450F.
(1) We ran a T.M. Designworks chain guide. This a
( 2) We added one tooth to the rear sprocket to enable
us to shift to third gear sooner.
( 3) We used a complete Hinson clutch.
( 4) We cut some threads off the rear master-cylinder
plunger rod to allow the brake pedal to move downward.
( 5) We tested all the maps, but as a group, the MXA
test crew was split 50/50 between the stock (green) and
aggressive (white) plug-ins. No one chose the mellow
WHAT DO WE THINK?
The Showa SFF TAC fork could either be a plus or a
minus on the KX450F. That’s not noncommittal—that’s
just acknowledging how complicated they are to adjust.
With the exception of the powerband and new front
rotor, the rest of the KX450F remains fairly mundane. ❏
MXA RODE TEST