Every one of us DR staffers was fighting to get his hands on Kawasaki's biggest bike of the year first. Luckily for me, I threw a leg over the off-road-specific offering from Team Green deep in the Arizona desert during the 2008 KLX450R introduction. Everyone else had to wait.
Set in the thick of 700 varieties of stab-happy cacti, Kawasaki's unveiling took on a low-tech, relaxing atmosphere-the complete opposite of the bike it was introducing or the philosophy behind it. While our two arid days in the striking desert landscape lacked the pomp and circumstance of an uppity introduction, the rural, in-the-rough setting was a perfect match for an off-road bike. And the KLX450R is an off-road bike-make no mistake.
One of the worst fears the off-road-riding contingent has is that a manufacturer will build a quick and dirty rendition of a trail or woods bike from a motocross-specific model. Fear not, my fellow trail hounds: The KLX is no motocrosser. While the new bike borrows most of its components from the Bubba-mounted KX450F, the trail attention it has received makes it more than capable off the racetrack. I racked up five hours on the bike in two days, and in between loops, photo shoots and delicately pulling vegetation spears out of my skin, I learned a pile about the new model and why it was working so well on the trail.
The first thing everyone notices about the bike is the exhaust noise, or lack thereof. The bike is ultraquiet, and that's awesome. An ultralow and long header pipe and a quiet spark arrestor-equipped muffler do a great job at keeping the bike whispering along while allowing the powerful motor to still work efficiently. This power, while plenty abundant, is calmly and greatly subdued when compared with the KX-F motocross version's. Starting at the bottom: The motor features a huge flywheel with twice the mass of the MX version. This has a great smoothing effect on the motor and throws down some serious traction-hungry power. Inside the flywheel, we get a 10-coil stator to power up the battery and lights. The other end of the crank is connected to a wide-ratio five-speed transmission with enough height in the gears to push this bike into some serious top-end speed. First is lower than that of the MX 450 gearbox, but the rest of the gears grow taller in comparison. On the trail, I used second and third exclusively and only went to first when I wanted the bike to rev up. (Sometimes it's fun to feel fast.)
The bike's low-decibel output is deceiving and tricks your brain into thinking that it lacks bottom-end power and that you need to downshift. However, once you test the bottom grunt in a third-gear corner, you'll find plenty of torque on tap to haul you through all but the tightest turns. This great bottom pull comes from revised cam lift and timing and a slight reduction in the diameter of both the intake and exhaust valves (to 36mm and 30mm, respectively). Swapping the titanium exhaust valves for more durable steel units is the only other head game Kawasaki is playing here.
The addition of an electric starter and some creatively effective clutch cable routing (the pull is so sweet) round out the motor updates for the new KLX.
Kawasaki took a similar approach to the suspension action on the new bike. Starting with the stock KX-F fork and shock, Kawi simply lightened spring rates, increased rebound damping and softened the compression all around. The end result is a great trailbike with plenty of plush to take care of the rock and roll of off-road. Spring rates dropped from 4.6N to 4.3N in the fork and from 54.0N to 50.0N on the shock. Faster riders, like the Kawasaki off-road heroes in attendance (Destry Abbott, Nathan Woods, Jeff Fredette, Larry Roeseler and Ricky Dietrich), will likely want to stiffen up the bike for full race situations. But for the average Joe, the bike's suspenders are really solid stock, make long rides easy to endure and can handle racing duty no problem.