Kawasaki Ninja ZX-6R And Kawasaki KX450F

Doin' Time - Staffers' Rides

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Kawasaki Ninja ZX-6R
Ari Henning
MSRP (2009): $9799
Miles: 1089-2051
Average Fuel Mileage: 29 mpg
Accessories & Modifications: Two Brothers exhaust and fuel controller, Hotbodies bodywork, ThinAir Concepts wrap, Galfer brake lines, Intuitive frame and axle sliders, Michelin tires

Sometime after backing it in past a competitor going into Turn 7 and carrying a power wheelie down the hill toward Turn 9, I realize just how phenomenal the 2009 Kawasaki ZX-6R really is. The qualities that impressed me when I first rode the new Ninja (MC, January) are even more inspiring in the heat of battle-in this case the AFM 600cc Superbike race at Infineon Raceway.

Since I love getting my hands dirty, preparing the Ninja for track duty was almost as much fun as racing it. A set of Galfer stainless-steel brake lines ($99.95 from www.galferusa.com) was left over from a previous project, so those went on along with fresh brake fluid. An order went out for an exhaust, and a week later a Two Brothers M-2 full system (complete with custom Motorcyclist badge and color-matched hardware for $1229.96) and Juice Box fuel controller ($299.98; both from www.twobros.com) arrived. While we haven't had a chance to throw the modded bike on the dyno, the pipe should be good for a few horsepower and definitely looks trick. The downside is a big drop in fuel mileage, from 34 down to 29 mpg.

The next box to arrive contained race bodywork from Hotbodies Racing ($649.95; www.hotbodiesracing.com), allowing the OE plastics to remain safely on the shelf. To spruce up the gray primer, we had the panels wrapped by ThinAir Concepts ($1499; www.thinairconcepts.com). Their color-printed vinyl wrapping is cheaper and easier than paint, and is limited only by your imagination. The ThinAir designers came up with several racy schemes for me to choose from, and even incorporated my newly acquired white expert numberplates. Removing the passenger footpegs, kickstand and other extraneous bits helped bring weight down. A lot: With a race-load of fuel, the Ninja weighs in at just 376 pounds, down 44 lbs. from stock.

Since Kawasaki trusts me enough to let me race their bike, you'd better believe I'm going to do my best to protect it. To that end I installed Intuitive Race Products front axle, frame and swingarm sliders ($225.90 from www.ofdracing.com). The frame sliders are a true "no-cut" design, and will work with the stock bodywork when the Ninja returns to street trim. For optimum grip, we spooned on a set of Michelin's delicious Power One radials ($247.09 front, $356.24 rear).

The last thing to do was safety-wire all the fluid-holding fasteners to insure that nothing vibrates loose and spills oil or coolant (replaced with straight water) onto the race surface. A long evening in the shop with a drill and a spool of wire and the Ninja is ready to pass tech inspection. Now, let's race!

With no points, I was gridded in the penultimate position: Row 10, Position 40. With the exhaust and massive weight loss, the Ninja is ferociously fast, and I had to hunch forward coming off the turns to keep the front wheel on the ground. Considering I never shifted past fourth, it's safe to say the stock gearing is too tall for racetrack use. Dropping a tooth on the countershaft sprocket and adding a few teeth to the wheel sprocket will improve acceleration, but will also mean more wheelies and shifting. A stronger steering damper is definitely in order, and perhaps a quick-shifter. While I didn't finish worth a damn (19th), the outing proved that the nearly stock Ninja is a capable racer-and a damn good choice for a long-term bike for this aspiring racer.

Kawasaki KX450F
Brian Catterson
MSRP (2009): $7549
Hours: Approx. 20
Accessories & Modifications:Kawasaki fork and shock springs, Vance & Hines exhaust, Dunlop Geomax tires

At the morning riders meeting, REM's Frank Thomason said something that made me question my dedication to motocross: "How you finish depends on what you did during the week and on the last two or three laps."

"Hmmm," I thought, "drinking, smoking and fading."

Though I'd handily won the 40-plus Novice class my first time out, my best result since bumping up to Intermediate was eighth. When I endoed out of that day's second moto and tweaked my shoulder and thumb, I was suddenly looking at six weeks off the bike. To make the best possible use of that time, I enrolled in a fitness boot camp (www.kuttingweight.com). Let the pain begin...

In my last update, I wrote that I was going to try to lose weight instead of getting the KX's suspension redone. I've since decided to do both. I had Kawasaki's techs replace the stock 4.6 N/mm fork springs with heavier 4.7 N/mm ($54.60) units, and the stock 52 N/mm shock spring with a 54 N/mm ($136.45). The bike now rides higher in the stroke with me on board.

Meanwhile I paid a visit to Vance & Hines, which recently entered the dirtbike market, filling the void left when White Brothers was killed off by the two firms' parent company. (Moment of silence please.) I mentioned that I had a long-term KX450F, and a few days later an XCR exhaust ($299) showed up at our offices. The squared-ellipse-shaped, brushed-aluminum slip-on connects to the stock head pipe with a stainless steel mid-pipe, and there's an optional spark arrestor ($44.86) for trail riding. It's noticeably quieter yet feels snappier in the low to midrange, even with the stock fuel-injection map.

A few weeks later, Dunlop held a press intro for its new Geomax knobbies. Successor to the popular D756s that came on my bike, the new MX51 intermediates are designed to work in everything from soft to hard-pack conditions, with added stability and durability. The event was held at Perris Raceway after biblical rain, and predictably the tires clung to the tacky dirt like Velcro. But they also worked well that weekend at sandy Glen Helen-right up until I went over the bars

More after I get back out there...

Binning the stock exhaust shed 14 pounds, and the raspy howl that comes from that carbon-weave canister sounds ferocious at 15,000 rpm.
Galfer brake lines improve feel. Intuitive axle and frame sliders are inexpensive insurance.
Lean, green and mean! Swapping the bodywork and changing the tires is a 3-hour ordeal-not bad for dropping a quick 30 pounds.
Vance & Hines logo looks out of place on a dirtbike, but the slip-on silencer/spark arrestor works well.