2015 Kawasaki Kx450f

2015 KAWASAKI KX450F

IGNITION

FIRST RIDE

The most versatile MXer gets another trick up its sleeve

Ryan Dudek

For the past few years, Kawasaki has made its KX450F highly adjustable. With two-position footpegs and four-position handlebar clamps, the bike has offered versatile ergonomics. Additionally, the KX-F has three ignition coupler maps for quick trackside changes to power delivery. And now, for 2015, Kawasaki has taken adjustability one step farther with the introduction of the Showa SFF-Air TAC fork. SFF (Separate Function Fork) isolates the damping and springing functions into separate fork legs, and a triple-chamber air spring allows for an extensive range of adjustability. Not to worry; this does not compromise the superb character of one of the most wicked motocross bikes on the market.

Although Milestone MX Park isn’t one of the roughest tracks in Southern California, it is chock-full of man-made jumps and obstacles. A few braking bumps and a couple of deep holes developed throughout the day to give me a solid impression of how the KX’s new fork works. In short, it gives the bike a completely different feel, sometimes better and sometimes worse. Gone is the ultra-plush feel and superb bottoming resistance of the old KYB pneumatic spring fork, which provided a very comfortable ride but lacked precise feedback. The new SFF-Air—i pound lighter than the KYB—gives the front end a lighter feel when tipping the bike into a corner and when trying to scrub a little speed off the face of a jump. Front-wheel tracking characteristics can literally be tuned to get the feel and feedback you want, whether that is plush or rigid as a board.

At the start of the day, the fork was mediocre at best, with unstable tracking and way too much movement through its stroke. After a half day spent fine-tuning, I was able to get the SFF-Air to perform and feel exactly how I wanted. With this baseline established, I should be able to go to any track and have a good starting point.

Although the SFF-Air cuts out the need for heavier or lighter riders to go up or down with spring rates, setup is critical. The best rule: Don’t overcomplicate setup. Running recommended air pressures (using the included 300-psi air pump) and tuning a couple of clickers should work just fine for most.

As on the previous KX450F, the engine’s class-leading brute power is found the moment you twist the throttle. Kawasaki says the 449CC motor has a new piston and ECU settings, but there were no noticeable improvements in power output or character.

When the new SFF-Air TAC fork is tuned to perfection, the KX-F shines as an open-classleading motocrosser. Let’s hope the complexity of its new fork doesn’t get in the way of the Kawasaki KX450F continuing to be the best race-oriented motocross machine available.

SPECS

2015 KAWASAKIKX450F

PRICE: $8699

ENGINE:

four-stroke single DISPLACEMENT:

449cc

SEAT HEIGHT:

37.8 in.

FUEL CAPACITY:

1.6 gal.

CLAIMED WET WEIGHT:

247 lb.

At first glance, the new $7,599 KX250F looks a lot like the 450F with its matching white rear fender, as both bikes have received identical aesthetic updates for 2015. The two even share features like launch control, changeable power couplers, and an oversize front brake disc that offers stellar performance and control while scrubbing speed. The 250F’s lighter weight, however, means better handling than the 450. Power is stout with plenty of over-rev to pull the rider off a jump without having to upshift before the lip. It’s no wonder 250-class riders are setting identical lap times to the 450 guys. -RD