After revealing an all-new KX450F for 2012, Kawasaki
returned for 2013 with significant updates to its 450 motocross mount. Along with some minor chassis and brake updates, the biggest change for the new year is the KYB Pneumatic Spring Fork (PSF) the functionality of which is further explained in our 2013 Kawasaki KX450F First Look
. MotoUSA was invited to Buellton, California to get a taste of the new machine at one of our favorite tracks, Zaca Station.
At first glance, the biggest noticeable cosmetic change to the bike is the all-new styling of the front number plate and fender, as well as the white back fender. The new styling lines deliver a factory race team look. Also new in the cosmetic department are updates to the engine appearance. The clutch and generator cover color has switched from black to silver for 2013 to reduce visual impact of wear due to rubbing of the boots when braking and shifting. At the end of two days of non-stop riding and a quick wash of the bike, the engine covers still looked brand new.
Along with its styling changes the 449cc liquid-cooled Single benefits from performance updates in 2013. Last year we found the 450 engine to be hard hitting with extremely aggressive power output, which made the bike hard to ride at times. This year, new ECU settings make the power delivery smoother from low to high rpm. Tuning settings, including a new piston and intake cams, do a good job leveling out the power but still offer the large amounts of horsepower we’ve grown accustomed to aboard the Kawasaki. Three different mapping couplers are offered again this year including the standard unit, a hard terrain coupler, and a soft terrain coupler which can be switched out in a matter of seconds depending on track conditions and terrain.
A new front master cylinder features a knocker-style lever for improved feel and more consistent performance than the old piston-type unit.
“Last year’s bike hit really hard and was almost difficult to ride at times,” explains Pro-level test rider Scott Simon. “The changes that Kawasaki made to the bike this year were definitely for the better. Now you can ride the thing, grab a handful of throttle anywhere you’d like and the bike isn’t trying to jump out from underneath you anymore, such a huge improvement.”
Although it may not seem major with only a new fork and revised swingarm, the KX450F’s handling updates are immediately noticeable and made an extreme difference. In just one lap we instantly found the added rigidity, due to the additional bracing to the swingarm, greatly enriched the KX handling. When entering corners and ruts the bike felt more planted and stable as it flexed less and tracked better than the previous year’s model. Overall the change provides more feedback to the rider in terms of confidence and feel on the bike.
Small changes were made to the rider controls, including a lengthening of each grip by 10mm allowing riders to move their hands a total of 20mm closer together. We find this to be a good feature for those like us that love to run grip donuts. Grip material is also softer and the rubber is no longer vulcanized to the throttle tube on the right and bar on the left side.
Pro-level test rider, Scott Simon, was not afraid to get a little bit nasty over the bigger jumps at Zaca Station Motocross track.
A new pushrod-type front brake master cylinder replaced last year’s knocker-style to help reduce stiction between the lever and piston. The initial bite and stopping power of the new brake hasn’t changed but we can definitely tell that the functionality has been eased up. Although our test rider couldn’t feel much of a difference in the updated front brake, I myself feel that rider feedback, along with more feel from the brake, was improved.
“I really couldn’t feel a huge difference in the front brake,” says Simon. “The brake is smoother at the lever but I couldn’t tell a difference in stopping power, the brakes work just fine.”
The biggest change this year is the Pneumatic Spring Fork. Changing spring rate is no longer a hassle. THANK GOD! That’s only the beginning, though. The new fork is state-of-the-art and its ease of use is phenomenal. The PSF may be the closest thing to a race-ready fork we have ever ridden on a production bike. Right off the showroom floor, a quick pressure set to the rider’s weight, and you’re ready to shred.
The fork is really plush and seems to have a different feel than a conventional style coil-spring fork. At first the front end feels soft, but once the pace is picked up you realize it’s not soft, you are just feeling the fork work. It’s simply incredible. It provides a lot of confidence to charge harder through rougher sections of terrain and feels as if you are riding on a cloud. A traditional pring fork seems to provide a lot more negative feedback including headshake and vibration. The PSF gives more of a floating feeling over braking bumps and hard impacts as if the front end remains on top of bumps rather than
The new 48mm KYB Pneumatic Spring Fork (PSF) uses pressurized air to eliminate the traditional metal-coil fork springs.
hopping in and out of them. With both Honda and Kawasaki switching to the new fork and the positive feedback already being taken from them, we suspect the rest of the OEM’s could make the switch in the near future.
Overall we are pleased with the changes Kawasaki made to their premium motocrosser for 2013. The updates only improve the bike for the better. One thing we would like to see is an air pump for the fork to be offered when purchasing the bike, as one is not provided. After riding the KX450F, we realized why Ryan Villopoto
is on the top of the podium each and every weekend, when he isn’t on the injured list. It’s a solid race package right off the showroom floor and is already available to the public with a price tag of $8699.
Engine: DOHC, 4-valve, liquid-cooled Single
Bore x Stroke: 96.0 x 62.1mm
Fueling: DFI® with 43mm Keihin throttle body
Compression Ratio: 12.5:1
Final Drive: Chain
Frame: Aluminum perimeter
Rake/Trail: 26.9 deg. / 4.4 in.
Front Suspension: 48mm inverted, Kayaba PSF with DLC coated sliders, 22-position compression and 20-position rebound dampening adjustment / 12.4 inch travel
Rear Suspension: UNI-TRAK® linkage system and Kayaba shock with 50mm piston, 22-position low-speed and stepless high-speed compression dampening, 33-position rebound dampening and fully adjustable spring preload / 12.4 inch travel
Front Tire: 80/100-21
Rear Tire: 120/80-19
Front Brake: Single rigid-mount 250mm petal disc with dual-piston caliper
Rear Brake: 240mm petal disc, single-piston caliper
Overall Length: 85.8 in.
Overall Width: 32.3 in.
Overall Height: 50.2 in.
Wheelbase: 58.3 in.
Ground Clearance: 13.0 in.
Seat Height: 37.6 in.
Curb Weight: 248 pounds (claimed)
Fuel Capacity: 1.64 gallon
Color: Lime Green
MotoUSA already reported its first ride impressions on the KX450F, now it’s time to deliver the goods on its little 250 brother – the revamped 2015 Kawasaki KX250F.
Kawasaki introduces a completely new suspension set-up on the 2015 KX450F, as well as changes to the braking system, engine and ECU. How does the green beast fare on track? Check out the 2015 KX450F First Ride to find out.