Video and Wallpapers!


Click to check out a video of Kawasaki's Russ Brenan talking through the 2010 Kawasaki KX450, and Pat Foster's ride impressions.


How about some wallpapers of the new Kawasaki KX450F?
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Polish and refine seemed to be the theme for this year's KX450F, but the changes are definitely noticeable. Click any of the photos in the article for a larger version.

Last year was one of those big revolutionary years for the KX450F. The big green thumper underwent a host of changes, like the jump to EFI, major changes to the frame and swingarm, and lots of other details. While this year’s update is more evolutionary than revolutionary, they’ve put together a slate of improvements that made people sit up and take notice when they got a chance to ride the bike recently. Let’s dive in and see what’s new.

Pat Foster flinging the new KX450F around Pala Raceway. Pat's a taller and more aggressive rider, and would definitely look at swapping out springs in favor of something a little more stout. But overall, he liked the handling.

While last year’s bike had some big changes in the chassis, they didn’t merely sit on their tooling for ’10. This time around there are plenty of added goodies. First up was the KYB AOS (Air/Oil Separate) fork, the only bike in its class with the DLC coating on the lower tubes to reduce stiction and smooth the fork action. They also got a dose of Kashima coating on the interior of the outer tubes, similar to what’s used by the Monster Energy Kawasaki team bikes.

With the fork guards removed, it's easy to see the DLC coating on the fork tubes. What you can't see is the Kashima coating on the interior of the upper tubes, or the separate Air-Oil internals.

The steering stem on the fork has been slimmed somewhat, from 24mm to 23mm in an effort to add a bit of flex back into the chassis, and improve front wheel tractability. Yep, while you’d think stiffer is always better, that’s not entirely true. You do need a big of fine-tuned flex built into the bikes.

In the rear suspension, Kawasaki engineers worked to improve stability and cornering, reduce kick, and improve traction by modifying the damping settings, and switching to a new rocker arm and link. The swingarm is also new, with a different cross-section shape, as well as a decreased wall thickness and height of the inside rib add a little flex back into the rear as well.

Spring rates for both the front and rear suspension help the balance between the two ends.

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Miscellaneous goodies would include thinner inner plates on the chain, new material and insulator on the new rear brake pads, a thicker front fender, and a seat with firmer urethane foam. The seat also has a slightly different shape.

For the first time, Bridgestone also gets OE spec as the tire of choice on both of Kawasaki’s top-end models, using an M403/M404 combo on the KX450.

Ready for a list of engine changes? There are lots of little details that add up to a seriously good engine.

A new bridged-box piston underwent testing with the team, and boosts strength while trimming weight. Combine that with changes to the cylinder, crank, cam, E.C.U., clutch and exhaust, and you've got a difference you can feel.

The new piston has a shorter profile, with a 6mm shorter skirt, as well as the addition of larger supporting side ribs, and a reinforced box structure. This is the same design that the team has been using for a while now. The piston pin is now 4.6mm shorter (50.3 to 45.7), and has a one mm smaller diameter to reduce reciprocating weight.

The skirt diameter on the new cylinder is 1.3mm thicker, and also extends 10mm further into the crankcase. This is said to boost piston durability, as well as providing additional cylinder/crankcase rigidity.

As for the crank, it now has more rotational inertia, and a revised profile that’s said to boost both torque and traction. The E.C.U. comes stock with a new operating program with revised settings, which adds response in the low-to-mid RPM range. You can still also purchase Kawasaki’s E.C.U. Setting tool, so you can custom-tune your ignition and fuel maps, or choose from one of seven pre-set maps.

With plenty of power, a wide powerband, and good handling to back it up, laying waste to berms was no problem on the big KX.

The cam’s changes include a revised sprocket, as well as moving the intake valve timing two degrees forward. This was done in an effort to not only boost performance, but to more closely match the new power engine characteristics they were looking for.

As you can see, the friction plates in the clutch have changed substantially between the '09 (left), and '10 (right). They also changed the shape of the operating plate.

The clutch gets a pair of upgrades, with changes to shape of the operating plate, for a better rigidity balance and oil drain from the clutch, as well as a better feel. This is boosted by the new friction plates, which have a full 75 percent more friction area.

In the exhaust, the silencer is now rubber-mounted, and the head pipe has been shortened to boost the top end, as well as placing it in a less vulnerable are and switching from titanium to stainless steel, both of which should add to its durability.

The difference in size between the new (left), and old (right) radiators is clearly visible. What you can't see from this angle is the boost in fin size and pitch. With the new radiators they were able to do away with brackets and support stays that were on last year's model.

In the cooling system, Kawasaki boosted the thickness of the radiators (to 32mm from 22mm), as well as making them wider (127.8mm, rather than 120.2mm). They also increased the fin size and pitch, which adds up to larger and stronger radiators that don’t require the brackets and support stays used last year, as well as increasing their tolerance to mud buildup.

Can you tell that Pat liked flinging the big Kawasaki around?
Hmm...we hear that the site of this intro, Pala Raceway, is on the short list of possible sites for a So. Cal. National...

So how does it all add up? There were plenty of smiles among the various testers on hand, and lots of positive comments on the power, handing, and overall package. For more detailed comments from Pat Foster (who was on loan from TransWorld MX, after a last-minute cancellation by our guest tester), check out the video above.

2010 Kawasaki KX™450F Specifications*

Engine: Liquid-cooled, four-stroke single with DOHC and four valve cylinder head
Displacement: 449cc
Bore x stroke: 96.0 x 62.1mm
Compression ratio: 12.5:1
Fuel Injection: 43mm Keihin Throttle body
Ignition: Digital DC-CDI
Transmission: Five-speed
Rake / trail: 26.7 degrees / 4.6 in.
Front suspension / wheel travel: 48mm inverted, Kayaba AOS with DLC coated sliders, 22-position compression and 20-position rebound dampening adjustment / 12.4 in.
Rear suspension / wheel travel: UNI-TRAK® linkage system and Kayaba shock with 50mm piston, 22-position low-speed and stepless high-speed compression dampening, 22-position rebound dampening and fully adjustable spring preload / 12.4 in.
Front tire: 90/100-21
Rear tire: 120/80-19
Front brake: Single semi-floating 250mm petal disc with dual piston caliper
Rear brake: Single 240mm petal disc with single-piston caliper
Overall length: 86.0 in.
Overall width: 32.3 in.
Overall height: 50.4 in.
Wheelbase: 58.3 in.
Ground clearance: 13.4 in.
Seat height: 38.0 in.
Curb weight: 250.4 lbs.
Fuel capacity: 1.9 gal.
Color: Lime Green
MSRP: $8,049

Wholesale distributor: Kawasaki Motors Corp., U.S.A.
9950 Jeronimo Road
Irvine, California 92618
(949) 770-0400

*Specifications are subject to change.

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