In Depth: 2013 Kawasaki KX450F
There is no secret that Kawasaki’s KX450F has winning potential. Since the bike was introduced in 2006, it has been atop the podium on countless occasions, is one of only three machines to click off a perfect AMA Pro Motocross season, has multiple national titles to it’s credit, and has been a part of four Motocross of Nations victories for Team USA. In other words, as far as racing credentials go, the KX450F has them in spades.
When the 2012 model was introduced, it received rave reviews for its refinements: a narrower frame with improved flex characteristics; Launch Control for better traction off the gate; the replaceable and programmable ignition map couplers; and adjustable height footpegs, just to name a few.
From the moment the bike hit the track, it was a winning machine, as Ryan Villopoto first raced the 2012 model at the 2011 Unadilla National (which he won handily), and went on a tear from there. He not only claimed the 2011 AMA Outdoor title, but also helped Team USA take the overall victory at the MXoN in France, dominated the inaugural Monster Energy Cup in Las Vegas, and won the 2012 Monster Energy AMA Supercross Series a record breaking four rounds early. With such a shining record, one would think a company would be wise to leave such a winning package alone. Not Kawasaki.
For 2013, the green machine was given some more royal treatment, simply because Kawasaki is aware that there is always room for improvement. In the motor department, additional tuning was smoothed for better power delivery from bottom to top end, and a revised piston and intake cam are intended to improve low end engine and throttle response.
For better stopping power, a new pushrod type lever/piston connection helps with a motor consistent feel, while a new 240mm petal-type rear rotor now has the same profile as the front rotor.
Of course, the coup de grace for the 2013 KX450F is the all-new Kayaba PSF (Pneumatic Spring Fork), which now uses air for compression damping as opposed to the traditional spring. The change from metal springs to air helped shave about 1.7lbs. off of the bike.
Rounding things off on the front end is a new upper triple clamp with four different handlebar mount positions, and for the first time since time began, both the KX450F and KX250F no longer have a vulcanized throttle grip. It is now glued on so you no longer have to shave the rubber off just to replace your grips. Riders rejoice.
Finally, just as on the KX250F, the forward swing arm casting has been extended another 20mm over last year to improve flex characteristics.
So what does all of this mean? In short, it all adds up to one very solid piece of motocross machinery. Now, when a rider is setting up the bike to suit his or her own riding style, the KX450F has almost all of the adjustability one needs built right in.
From the different handlebar mount positions and footpeg positions, to the already comfortable cockpit and tunable ignition mapping, to the PSF forks, riders are less slaves to bike shops than ever before.
As a taller rider, I felt that the rider compartment is more open and comfortable than some other bikes. We chose to drop the footpegs down 5mm but kept the handlebars in the second forward position (meaning the rear mount on the clamp with the handlebar mounts turned forward) and that was plenty to open the bike even more.
On the track, no matter the conditions, the KX450F feels very planted and predictable. From rutted corners, to dried out braking bumps, the bike tracks straight and true as the frame handles wonderfully while the PSF fork and shock feel very well balanced.
The PSF fork (affectionately referred to as the air fork) is very easily adjusted. As we mention in our video, the stock setting is 35 PSI, and depending on your riding style, type, and ability, you can go up or down from there. In addition, there are still the traditional clicker adjustments for both compression and rebound. With the ease of use and extremely plush action of the fork, whether going to a stiffer or softer setting, it is hard not to think that this is the future of motocross suspension.
The fact that both Kawasaki and Honda have committed to this new technology for 2013 on their flagship motocross offerings should be evidence enough. But when you finally get a chance to use the PSF, there is no denying that it is very good stock suspension. Being able to essentially change your spring rate with a high-pressure air pump (the same kind used for mountain bike suspension) passes much of the work of suspension setup into in the users' hands, although the the forks can still be revalved for even more refinement.
Perhaps one of the more unique attributes of the PSF is that each leg can be fully bled of air to completely compress the travel. Why is this cool? With the travel fully compressed, the KX450F can fit into a wider variety of vehicles (i.e., possibly some minivans), and can now fit into an average sized suitcase if you need to travel with your suspension. Bonus!
Back to the track, the coupler system is another excellent Kawasaki innovation. Again, depending on track conditions and riding style, the soft coupler (with a more aggressive hit for softer conditions) standard coupler (with a broader power curve) or the hard coupler (meaning a softer hit for hard pack or slippery conditions) will suit different riders at different times. The key is that they are noticeably different.
At Zaca Station, the track was ripped deep enough in the morning that the soft coupler was the way to go with a strong hit off he bottom that was enough to keep the front end light in the soft stuff. As the track broke in, an aggressive, faster rider, such as Bryan Wallace (our fast guy for the day), liked to stick with the soft coupler, while I found the standard coupler to be my preference when traction was not always guaranteed and the bumps got bigger.
A Kawasaki technician was on hand, and we were able to use a custom mapping setting that he had come up with specifically for Zaca Station. His setting was somewhere between the hard and standard couplers, still with plenty of power down low but not so much that the bike wanted to break loose in drier spots of the track.
Overall, Kawasaki has put together an excellent package for 2013. Of course, there is still more testing to be done, but so far the new KX450F left us with a desire to get back out on the track…and that is a good thing.
Check out the video below to see the new bike in action.