Kawasaki fit both the machines with a lighter subframe,
stronger brakes, and great adjustability at the bars and pegs.
The big news with the KX450F is, of course, the new
Triple Air Showa SFF fork. Last year’s bike had an air fork,
but it was a KYB unit. The Showa SFF Triple Air has more
adjustability and definitely chews on the smaller track
gremlins better than the KYB. The pluses are adjustability,
plusher on hack and since the majority of the main spring
(air) is contained in a sealed cartridge, blowing a seal
will not render the fork useless. Our other quick impression was it tended to blow through the stroke fairly easily
and required damping adjustments in order to keep it up
in the stroke, whereas last year’s machine loved the big
launch, so this is an area where we will spend time dialing
and adjusting. Finally, having to check three separate air
pressures before you ride is not a fun deal, and it takes
a substantial amount of time and is most definitely a new
learning curve that is crucial. With the rear shock we made
one change, set the sag and then rode the rest of the day.
It felt pretty darn stable, made for good traction and took
a good smattering of hits like a high-end motocrosser
In the engine department, Kawasaki made subtle
changes, mainly in the ECU, more compression via the
bridged-box piston and targeted mid-to-top-end hit. And
they succeeded! This machine is faster, but it also feels a
bit lean, is a shade harder to start (last year it was the best
non-button starter of the 450s), but makes a very feelable
mid-hit increase that is more reminiscent of older KX450Fs.
Kawasaki made big improvements to the braking power
via new Braking 270mm front rotors (for both the 250 and
450) and also fit a Braking rear rotor, which, too, has better
feel and power.
Power seems to be about the same as last year with no
really big changes. It has a good, strong bottom end and
midrange, signs off a little early, but compared to the other
250Fs, it has good top end.
The KX250F uses a Showa SFF fork, but is sprung with
a spring, not air. It has new settings that focus on keeping
it “up” in the stroke. By fighting the dive, the new fork is
most definitely a stronger performer and, like the 450, the
rear Uni Trak took little to set up and was praised by the
Three big hits with the 250F came in the new top triple
clamps with a vast array of adjustability, the adjustable
footpegs (both higher and lower) and the brakes, which
was positively commented on by all. ❏
The new Showa Triple Air fork takes the big hit decently, but
does tend to blow through the stroke more so than the KYB.
The 2015 KX250F is a strong performer down low and into
the middle hit. There are very subtle changes to the new
machine, but stronger braking and a more planted suspension feel are highs.