A little goes a long way—that’s the mantra behind Kawasaki’s new 2012 KX450F ($8399) as Team Green’s flagship 450-class motocross bike receives a number of tweaks that help take performance to the next level on the track and trail. To take a closer look at all of the technical updates read the 2012 Kawasaki KX450F First Look as this review will focus on our riding impression from Michigan’s Red Bud motocross track—site of Round 6 of the Lucas Oils AMA Pro Motocross Championship.
Take a look at the new KX450F and it appears leaner and meaner than before. Although the silhouette of the engine and chassis is essentially unchanged, the bodywork is new as is the profile of the gas tank, seat and muffler. The changes were made not only to give it a more contemporary look but to make it feel more compact. As usual it continues to come equipped with factory-esque black wheels, plus blue anodized fork caps, shock compression adjuster and oil and generator caps. Another cool styling touch is the embossed clutch cover that makes the bike appear less haggard during the course of normal wear and tear.
Lift the bike off the stand and there’s no denying that it is still a heavy machine weighing in at 249 pounds with a full tank of fuel (roughly the same as last year’s bike). Speaking of fuel, the capacity of the tank has been reduced by 0.26 gallon to 1.64 gallons. Swing a leg over it and it feels considerably slimmer through the mid-section. Engineers managed to reduce its width my 4mm though the change feels considerable. The way in which the rider interacts with the motorcycle was a key focus for ’12 and the Kawi now allows the rider to easily adjust the position of the handlebar and footpegs. Additionally an optional rear suspension link lowers the height of the seat by nearly a quarter inch. Even with the changes, the KX is one of the larger feeling 450s which is perfect if you’re of above-average height.
(Above) The open cockpit made the transition from sitting to standing very easy. (Center) The 2012 KX450F going over one of Red Bud’s wonderful tabletop jumps. (Below) For 2012 the green machine comes with Bridgestone tires which made you feel glued to the ground.
As usual, getting the engine fired is as simple as a light thrust of the kickstart lever with its fuel-injected motor roaring to life within one or two kicks regardless of weather conditions or if the engine is hot or cold. Out on track the Kawi’s insanely powerful motor continues to impress us with tremendous, yet controllable, power at virtually all rpm.
“Kawasaki has never had a slow motor by any means,” says pro-level rider and Editorial Assistant, Chris See. “With the standard map it has great bottom-to-mid pull but as it gets to the top-end it hits a big flat spot. It could use a one- or two-tooth smaller rear sprocket depending on the track.”
Through the use of Kawi’s ingenious Fuel Injection Calibration Kit and a new tunable ignition coupler system, reworking the engine’s powerband to suit rider and/or track conditions is a simple affair.
“With its adjustable fuel and ignition maps you can work around the gearing,” continues See, “and basically ‘build’ the powerband to your liking. For the most part we used a custom ‘Red Bud 5’ map. It reduced the hit on bottom then picked it up a little in the mid and made it come alive on top. This made the bike way easier to ride and I think it would be enjoyable for a variety of racers.”
As See mentioned, the Kawi’s dynamic and user-adjustable power mapping now features a clever jumper system located on the right-side of the frame head stock. This allows riders to select from one of three pre-programmed maps without the need of plugging in a computer or breaking out the tool box. The green coupler contains the “standard” map, while the white jumper is the “soft-terrain” map designed for maximum power hit in the sand or at deep, loamy tracks. The black coupler is the “hard-terrain” map designed to reduce initial power hit on more traction-limited surfaces. It also works well for riders looking to take some of the edge of its snappy powerband. Furthermore each coupler can be re-programmed with any sort of map.
“When the track got hard, bumpy and rutted I liked the hard-terrain setting because it increased traction. More power went to the ground instead of just spinning the back wheel,” explains See. “I think this map would be great for your second moto when you don’t want that arm ripping power that you would start the day on.”
(From full stiff)
Low-Speed Compression: 10
High-Speed Compression: 1 ½ turn
The Kawi has been known for its high-level of stability and composure on rough tracks so it isn’t much of a surprise that it continues to impress us in this area. Though suspension spring rates remain the same the valving has been modified to work with the redesigned frame, triple clamps and swingarm. Front-to-rear suspension balance is excellent and the bike doesn’t appear to have any quirky handling traits. A slimmer 80-series Bridgestone M403 Intermediate Front Tire made the KX feel like it steered with a heightened sense of agility, though it still isn’t the sharpest steering bike out there. But at the same time it also doesn’t appear to have any significant handling quirks making it one of the easier bikes to pound out laps on.
(Above) The KX450F has had a tendency to stand up mid-corner but it feels much better for ’12. (Center) For shorter riders the fully extended cockpit seemed to be a little to open, or at least for our test rider Chris See which is 5’ 10”. (Below) The suspension received minor updates for 2012, but for faster riders it is still a bit on the soft side for faster riders.
“In some ways they were for the better and others still need some improvement,” comments See in reference to the update suspension settings. “The fork felt better through the first four inches of stroke, but once past that the bike felt as if there was no more valving and would deflect off bumps instead of absorbing them. I slowed the compression three clicks and sped up the rebound by two clicks.”
“Out back I brought the rear end up, changing the compression by two clicks slower, sped up the rebound one click and increasing the high-speed compression adjustment by one quarter turn to increase the ride height and balance the bike out,” See continues. “Overall the 2012 suspension was better but still overall a little soft for my liking on the front end. As for the rear, it worked great and I wouldn’t even need to adjust the valving on it until it was time for routine maintenance.”
Perhaps one of the coolest features of the KX is its new push-button launch control mode designed to maximize the forward acceleration at the start of a race. To engage, simply hold down the button on the left-side handlebar (in neutral, first or second gear) for a few seconds until it begins flashing. The ECU then reverts to special ignition timing that reduces the chance of the rear wheel spinning and/or the bike wheeling too aggressively. It automatically deactivates as soon as the rider shifts into third gear. The electronics allow you to pin the throttle (with the engine bouncing off the rev-limiter) then aggressively feed in the clutch and the bike rockets forward in a smooth, slightly restricted-feeling. For sure the system kills drive a bit and a faster launch can still be achieved by a highly experienced starter or seasoned pro, but for the vast majority of amateurs, myself included, it definitely makes starting a whole lot less complicated.
Like always the Kawi’s latest 450 continues to impress us with the mind boggling performance of its engine harnessed in a stable and relatively easy to manage chassis that features more adjustment than ever before. This makes it easier for the KX rider to get comfortable at its controls and extort the astronomical level of performance that this bike is capable of. Factor in Team Green’s fantastic amateur race support and contingency and the KX450F is an excellent choice to go racing with.