2010 Kawasaki KX450F First Look

For 2010 the KX’s essential platform returns, and although it’s nearly impossible to spot the individual changes, both the engine and chassis have been modified in order to deliver more performance around the racetrack.

Powering the KX is a 449cc 4-stroke Single that benefits from all the latest and greatest engine tuning tricks including liquid-cooling, double camshafts and fuel-injection, just like before. What’s new is the piston, cylinder, camshaft and crankshaft. For these components engineers turned to the racing department and utilized the same parts that they’ve been successfully running this year.

Perhaps the biggest change in terms of engine performance is the new piston. It’s both lighter and shorter for better performance through its 11,300 rpm-range (compression ratio remains the same). It slides inside a redesigned cylinder featuring tighter tolerances between it and the crankcase. The crankshaft is also new and makes use of a fresh design said to improve the engine’s tractability between the rear tire and the ground when you twist the grip. Lastly, a new camshaft was fitted and advances engine timing by 2-degrees.

The 2010 KX450F clutch set-up also gets some attention with a reengineered basket designed to not only enhance feel but operate cooler as well. The fiber friction plates were beefed up and contain more friction material which increases feel and durability. The same 5-speed transmission transfers power to the rear tire but it now does so with a slightly lighter chain.

With the electronic revolution, no hardware upgrades can be complete without software updates to match, so engineers reprogrammed the fuel and ignition settings in the ECU. Additionally, the rider or engine tuner has the ability to alter all the engine settings via an optional Kawasaki Fuel Injection Calibration Kit.

Like before, you’ll be hard pressed to find a rider that thinks the Kawi needs more juice even in stock form. And it doesn’t matter what gear or rpm you operate the engine. Just twist the throttle and the KX rockets forward with the immediacy of a sportbike. Yet at the same time it generates power in such a linear, predictable fashion that it won’t catch you off guard or scare you, even if you’re new to the sport (again, the Kawasaki Fuel-Injection Calibration Kit allows you to tune the bike’s engine to deliver power more or less aggressively based on your skill level and track conditions check it out, it’s the best money you’ll spend on your new KX).

All said and done, the 2010 Kawasaki KX450F costs $500 more than its predecessor and should be rolling into your local Kawi dealer as you read this. Although the changes aren’t revolutionary and are pretty difficult to feel in the hands of your average motocross pilot; in the hands of our pro they made a difference. Most notable was the engine’s more friendly power delivery as well as its improved handling in the corners. So, if you’ve already got a ’09 bike in the garage is it worth making the upgrade to the ’10 model? If you’re serious about racing than it’s a no brainer.

MSRP $8,049

2010 Kawasaki KX250F First Look

Most were hoping the trickle-down effect would happen fast enough for this year’s bike to trade its carburetor for digital fuel injection, but it wasn’t to be. Try not to be too disappointed, though. Try to remind that the ’09 was a damn fine machine, and a list of improvements aimed at bettering the handling characteristics is a good thing.

Kawi’s quarter-liter gets a bridged-box piston design like the KX450F as well as the wedge-shaped crank web and larger radiators. But, unlike its big brother, the exhaust pipe is longer out of the head and shorter in the middle for boosted low-end grunt. Crankcases are thicker and the tranny is beefed up as well with bigger dogs on third and fourth gears.

Suspension and chassis changes are just like the 450 except that the KX250F uses Showa components. The steering stem has less rigidity and the suspension tuning aims at leveling the bike’s stance so that there is less pressure on the front wheel. Showa twin-chamber fork, along with revised frame geometry are designed for quicker steering. The suspension also features a super-hard titanium coating on the outer surface, and a friction-reducing Kashima Coat on the interior. The 450 uses Kayaba forks

That doesn’t necessarily equate to quicker handling in the hypothetical world, but we’ll wait and see how this thing turns at the press launch.

Sure seems like there’s a lot in common with the 450F, and the price hike is no different. If this is the bike for you, the 2010 model rings in at $6999 - an extra 500 bucks over the ’09.

2010 Suzuki RM-Z 250 First Look

After being the first brand to introduce a fuel injected 450 Suzuki again got the holeshot in hte 250 class. The 2010 RMZ 250 is the first MX2 bike from Japan that received some extra electronic to get going. Suzuki racing technology is everywhere you look: advanced Suzuki fuel injection is fitted for the first time on a four-stroke 250cm3 Suzuki motocross machine. Further engine modifications boost peak power without giving up any of the low-end or midrange that has made the RM-Z250 the choice of top riders everywhere. Chassis updates improve handling with key suspension upgrades making the new RM-Z250 the perfect weapon for motocross racers worldwide. And there’s the eye-catching slim, aggressive styling that causes the RM-Z250 to stand out at any track.

The Suzuki RM-Z250 dirt bike has come a long way since its joint conception with Kawasaki back in 2004. Now solely a Suzuki product, the RM-Z250 has become a known motocross race-winner in the hands of riders like Ryan Dungey. Suzuki was the first Japanese OEM to introduce production fuel injection on its motocross bike, the Suzuki RM-Z450, and it is also the first to do it with the 250F division. The 2010 Suzuki RM-Z250 will be equipped with battery-less EFI for the first time to fuel the liquid-cooled, DOHC 4-stroke Single.

Suzuki has always been known for producing bikes with razor handling, and the RM-Z250 adheres to that formula. Nimble and quick, holding the inside line is its forte thanks to a twin-spar aluminum chassis and Showa suspension on the new models. The Suzuki RM-Z250 has finished as high as second place in our annual 250F Motocross Shootouts, but the overall class title has remained elusive for the RM-Z250. However, it shows up as one of our riders’ favorite bikes to spin laps on which goes to show that the Suzuki RM-Z250 always has plenty to like about it. Factory race teams like Rockstar Makita Suzuki are in the title hunt with the RM-Z250 at every race series including motocross and supercross.

MSRP $6,699

2010 Yamaha YZ250F First Look

The YZ250F for 2010

The all new, bilateral beam frame is specific to the 250F and is more compact than the previous generation chassis for superior cornering. The optimized engine delivers a new level of power in the low-to-midrange, with a great torque feeling that all riders want!

Starting at $6,990 for the blue and white, and $7,090 for the white and red.

KEY FEATURES

The all-new, Bilateral Beam frame is specific to the 250 and is more compact than the previous generation chassis. This places the rider closer to the front wheel, which delivers superb rigidity balance for unmatched lightweight handling and cornering. This nimbleness lets the rider get on the gas sooner out of corners and cross the finish line with less fatigue – even on long motos.

The optimized engine delivers a new level of power in low-to-midrange, with a great torquey feel, exactly where riders want it. That is due to the new straight intake boot that enhances breathing, new carburetor that provides excellent throttle response and fuel atomization, and redesigned valve train components that reduce inertial mass and boost low end torque. Exhaust is also enhanced with a new D-shaped exhaust port and newly designed exhaust system. Ongoing refinement to the suspension and engine produces an amazingly balanced, light-handling machine with performance that’s accessible to all levels of riders.

All new styling emphasizes the bike’s light weight and nimble handling character. The sharp, horizontal lines set the bike apart, with a clean, aggressive look.

KYB® suspension has been recalibrated front and rear and is tuned to work with the new Bilateral Beam frame for unmatched handling. The clutch lever has a lighter pull feel even though the clutch has stronger engagement. The new clutch also has a wider engagement range that will give riders an advantage off the line. . . shift after shift, moto after moto.

There’s no disputing the YZ250F’s unmatched four-stroke prowess – it was the 1st four-stroke 250 motocross bike on the market, the 1st to win an international race, the 1st to win an AMA® Supercross ® and the 1st to take an AMA® U.S. Supercross Championship® title, as well as the first to win an AMA® National race.

2010 Honda CRF250R First Look

The CRF250R for 2010

(from Honda motorsports brochure)
starting at $7,199

The CRF250R likes to win. Plain and simple. In fact, this machine has grown so used to taking checkered flags that it considers the top of the podium home. It's not easy, though, because when you're this good, everyone else is always gunning for you. And that means you always have to stay that much better, which is exactly what this year's all-new-from-the-dirt-up Honda CRF250R has done.

And we didn't have to look far for inspiration, adapting many of the same cutting-edge features found on the open-class-leading and championship-winning CRF450R. Like Honda's revolutionary batteryless fuel-injection system. A lightweight, more potent Unicam engine. An innovative new single exhaust setup. An all-new twin-spar aluminum frame. And our exclusive Honda Progressive Steering Damper (HPSD). It even takes some serious new styling cues from its big brother.

And the result? The lightest, most powerful and best-handling CRF250R yet. Once again, it looks like everyone else will be racing for second.