Posted March 30, 2007   Email   Print

Kawasaki's KLX450R combines trail manners with blistering speed in a flexible package

By James Holter
Photos by Mark Kariya

Nature's revenge has a name, and it's the cholla cactus. This small, scraggly plant looks innocent enough, but even lightly brush it with a loose jersey, and it snags fast, breaks off in clumps and plunges as much as half the length of its inch-long thorns into your skin as your clothing snaps back against your body.

It gets worse. Barbs on the needle-like thorns keep them planted until you can find a pair of pliers to pull them out. If you're lucky, you won't break the thorn off at the skin.
And right now, about 50 miles northeast of Phoenix, I'm riding Kawasaki's all-new 2008 KLX450R through a sea of the stuff.

Inches (sometimes less) from my elbows the cholla flies past. If I make one mistake—grab too much throttle, push my front end through a turn—I could be looking at a long night pulling thorns from flesh.

You'd think I'd be nervous right now, considering I'm riding one of the most aggressive off-road race machines available today.

And, to be honest about it, I was nervous this morning, while looking over the bike back at the Kawasaki semi.

Even though I was told the KLX has several off-road-friendly tuning changes from the motocross version—the KXF450R that James Stewart is using to dominate the Amp'd Mobile AMA Supercross Series—I still expected much of the explosive, non-stop power that characterizes the original. While a different exhaust, heavier flywheel and revised cam timing can make a difference, the engine is still fundamentally the same.

But as I discover when I start my first trip around a 23-mile loop of two-track, goat trails and sand washes, the KLX450R is immensely rideable. The power from the four-stroke motor builds in a smooth, linear climb from idle to wide-open. The cholla becomes a white-trimmed green blur as my confidence builds and I start to crank the throttle a little harder.

That impression is only reinforced as I come to the single-track that crosses up and over the hills around the perimeter of the flat desert. I click the five-speed transmission down into second and start to climb the loose rocky trail meandering toward the ridge above.

The trail isn't terribly steep, but it's long and full of tight turns. Toss in the loose rocks, and experience tells me that I should expect to shift down into first long before I reach the top.

The motor, though, is perfectly happy with second gear. It chugs along at near idle as the bigger flywheel keeps the crank spinning after I roll off the throttle. In fact, I never stall the bike in this situation, even when I purposely lay off the clutch and rely on the motor to do all the work.

Not that the clutch was much of a chore. Although the KLX450 uses the same heavy clutch springs that are in the KXF450, which are necessary to transfer the power of the 449cc engine to the transmission, the lever pull is noticeably lighter. In fact, it feels more like the clutch pull of a 250cc rather than a 450cc bike. Kawasaki engineers on hand say the only change is a more direct cable routing and a different lever ratio at the actuating arm inside the left-side engine cover. It works.

Between the climbs and descents, the trail loop leads me through another fun feature of the desert, the sand washes that casually drift between the hills.

These offer up an excellent test of the KLX450's suspension in its intended environment. Both ends soak up the rock gardens, jagged stair-stepped ledges and drop-offs that mark the sand washes without a whimper.

And when the trail opens up and the rocks give away to deep sand, both ends carve predictably through the silt. The front end is particularly forgiving in the sand whoops that follow. Even when I miss-time a section or take a bad line, I never lose confidence in the front end, even when I let it drop between two whoops and it slams into the face of one.

There's a lot of good about the KLX450R, but the most distinguishing feature of the bike isn't what it does. It's what it doesn't do.

And what it doesn't do is make noise.

Having a conversation while sitting on your dirt bike and letting it warm up with the choke on are no longer mutually exclusive. Even better, the relative quiet continues when the throttle is cracked open. The KLX450R is a very neighborly motorcycle, and for a four-stroke race bike, that's a pretty significant accomplishment.

In addition to the revised suspension and motor, Kawasaki bolted a lot of other off-road goodies on the new KLX. A digital instrumentation cluster has a speedometer, twin tripmeters, odometer and clock. The plastic fuel tank, complete with reserve, meets environmental regulations and holds 2.11 gallons of fuel. The airbox was even redesigned with off-road use in mind, lacking the side vents of the motocross version to prevent water from seeping in, while the left side allows easy access to the air filter.

Out back, an 18-inch rear wheel lets riders choose from popular off-road tread with higher sidewalls that are better suited to absorbing sharp-edged rocks and resisting flats. A 10-pole stator kicks out more than enough juice for the 35-watt headlight and energy efficient LED taillight.

The best addition, though, is the electric starter. The KLX still has a kickstarter back-up, but the magic button is a godsend on the trail, when all it takes is a quick push, instead of several tiring kicks, to get moving again.

All the changes tack on a few more pounds to the motocross version, bringing the dry weight up to a claimed 253 pounds, and add $400 to the price tag, making for an MSRP of $7,299.

If there's anything about the KLX450R that defies its otherwise widespread appeal, it's that ergonomically, it feels like a big bike. While I felt like the machine fit me fine at six-foot, riders more than a few inches shorter might feel a bit stretched in some situations.

I also found the shifter a bit difficult to get a toe under, an issue that was more an inconvenience than a real problem, particularly since I could literally ride for miles in a wide range of terrain without looking for a different gear, thanks to the enormously flexible motor.

My only other quibble was the bike looked well-worn after a little more than 60 miles of desert riding, but I'm tempted to say that had as much to do with the harsh desert conditions as it did with the bike's cosmetic resilience.

The KLX450R is a model standard for the modern four-stroke off-road dirt bike. It has forgiving trail manners that rival traditional play bikes, but its performance capabilities surpass the limits of all but the very best off-road racers. This is a motorcycle that can be used to comfortably follow kids around a campground or competitively race any class at a local harescramble.

It's designed to tackle everything and to instill confidence while doing it. And it does so. Very, very quietly.

It should be available at your local Kawasaki dealer in about a month.

2008 Kawasaki KLX450R
Engine	Liquid-cooled, four-stroke, DOHC, four-valve single
Displacement	449cc
Bore x stroke	96.0mm x 62.1mm
Compression ratio	12.0:1
Carburetion	Keihin FCR
Ignition	Digital AC-CDI
Starting	Electric, with primary kick backup
Transmission	Wide-ratio five-speed
Final drive	O-ring chain
Frame	Aluminum, perimeter design
Rake	27.1 degrees
Front suspension	48mm inverted AOS-type cartridge fork with 22-way compression damping and 20-way rebound damping
Rear suspension	UNI-TRAK single shock with 22-way low-speed, two-turn variable high-speed compression damping and 22-way rebound damping
Suspension travel	11.2 inches front, 11.0 inches rear
TIres	80/100-21 front, 110/100-18 rear
Front brake	250mm petal rotor with hydraulic dual-piston caliper
Rear brake	240mm petal disc with hydraulic single-piston caliper
Overall length	85.8 inches
Overall width	32.3 inches
Overall height	49.4 inches
Seat height	37 inches
Wheelbase	58.3 inches
Ground clearance	12.6 inches
Fuel capacity	2.1 gallons
Dry weight	253.5 pounds
Color	Kawasaki Lime Green
MSRP	$7,299

© 2007, American Motorcyclist Association