Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/128399
THROTTLE TIME (Left) The KX450F is being assembled at the factory as we speak. It should start hitting showroom floors by early to mid-October. A 449cc four-valve DOHC motor powers the new Kawasaki. The exhaust system is made out of titanium (as is the heat shield) and is tapered. It starts off 38mm in diameter and expands to 41 mm, which Kawasaki says contributes to its braad powerband. (And that, it has.) During development, Kawasaki discovered that test riders simply never used fifth gear, so they got rid of the unused gear and made the bike a four-speed. They figured this would also save weight and keep the engine cases nice and compoct. And since this bike was designed strictly for the track, the better versatility of a five-speed tranny was not an issue. The oHrood guys are bummin', though. (Above) Kawasaki refined the 450 with aluminum Renthal handlebars, titanium faatpegs and brackets, and special handgrips. 2006 Kawasaki KX450F $6799 Liquid-cooled. four-valve. DOHC. four-stroke DISPLACEMENT: 449cc VALVES: Titanium BORE x STROKE: 96.0mm x 62.1 mm COMPRESSION RATIO: 12.0: I CARBURETION: Keihin FCR40 wlthrottle position sensor (K-TRIC) IGNITION: Multimap digital COl TRANSMISSION: Four-speed CLUTCH: Wet. multidisc FRONT SUSPENSION: .48mm inverted. Kayaba A05 w/22-way compression and 20-way rebound damping adj. REAR SUSPENSION: .... UNI-TRAK single shock w/22-way low-speed and two-turn high-speed compression damping. 22-way rebound damping FRONT·WHEEL TRAVEL: 12.4 in. REAR-WHEEL TRAVEL: 12.4 in. FRONT BRAKE: 5emi-noating 250mm disc REAR BRAKE: 240mm disc FRONT TIRE: Dunlop 901100-21 in. REAR TIRE: Dunlop 120/80-19 in. SEAT HEIGHT: 38.0 in. WHEELBASE: 58.5 in. GROUND CLEARANCE: 13.6 in. FUEL CAPACITY: 1.9 gal. CLAIMED DRY WEIGHT: 220.1 Ibs. COLOR: Green MSRP: ENGINE TYPE: Even though they're quite slim, we doubt that overheating will be an issue with these new Denso radiators that feature tightly packed cores and a new fin design. Even the aluminum skid plate is trick. It's small and tucked in behind the bottom frame rails. Even though we've had the to<450F in our possession for just a few days now, we've already fallen in love with it. The first time we rode it. from the pits to the track, actually. the bike already felt light, nimble and well balanced - almost like a 250cc two-stroke. But once we got on the track and opened up the throttle. we were quickly reminded that this is indeed a 450. This bike has power and lots of it. But that's not surprising. really. After all, it is a 450. But what is surprising is how easy the bike is to ride. The motor is supersmooth. especially from bottom to mid, and you can ride it there all day long while laying down some good laps, or you can hold the throttle wide open and ride it as fast as you dare. It's your choice. and the to< is willing to oblige. We found that the to< has so much torque that when in doubt, just click up another gear and go. The rear tire hooks up nicely, and the motor pulls well off the bottom. The bike just keeps pulling and pulling smoothly until you're just too chicken to go any faster. As one tester said. "It's definitely fast but it's easy to use the power." So far, we like the to<'s four-speed transmission. We've ridden the bike at two significantly different tracks so far and found that you pretty much just hang out in third and fourth gears all day, mostly staying in third. First gear is Virtually useless and second gear gets lonely; third and fourth gears are definitely the workhorses of the four. None of our test riders have yet complained about not haVing a fifth gear. So. it appears that Kawasaki figured out the right combination for the bike's power-to-gear ratio. But we still have a lot of testing ahead of us. Starting the big to< has yet to give us any problems. It has an auto-decompression system and a hot-start lever just in case. and we've never had to kick more than twice to get 'er running. The to< is extremely comfortable. When we hopped on it fpr the first time, we immediately feel right at home. The handlebars are well pOSitioned, the seat is cushy, and the layout is nice and nat. Very neutral. On the track, the to< feels remarkably nimble. It takes little effort to make it do what you want, and when it comes to the turns. just slide your weight on top of the tank, and it goes wherever you point it. It sticks in the turns, and if you're in a rut, it stays there; you don't have to worry about it popping out. This also might have something to do with the somewhat oversized tires that Kawasaki fitted the 450 with. The to< uses a 90/100-21 tire up front and a meaty 120/80-19 tire in the back. Surprisingly, they're Dunlops. Kawasaki's race team uses Bridgestones, and so does the '06 to<250F. Even though we have yet to have the chance to weigh the bike, we were told it actually tips the scales in the upper 220s. which seems about right to us. But when you're onboard, it feels a lot lighter than that. For a 450, it's very flickable and maneuverable. We found the 450's suspension to be a tad on the spongy side. As a result, the bike felt a little wallowy down fast straights, especially when the dirt was soft. The fix was Simple. though, as we just went in a couple of clicks on the compression at both ends and that calmed things down significantly, giving the bike a more stable feel. Otherwise. both the fork and shock performed well. So far, there is nothing about this bike that we really don't like: It's light, fast, has good suspension and handles extremely well. So, if Kawasaki was looking to make a good first impression, it certainly did with us. Our upcoming 450 shootout should be quite intereN esting, to say the least. CYCLE NEWS • OCTOBER 12,2005 49