The Kawasaki KX450 is arguably the most highly anticipated motocross bike of 2019. Everything, including the model name, is new. Kawasaki’s flagship motocrosser features an all-new electric start-equipped engine, a Showa 49mm coil-spring fork, a new Showa shock, and a completely revised chassis. The KX450 is also the first Japanese motocross bike to come with a hydraulic clutch. Kawasaki’s efforts with its latest-generation KX450 paid off with a big win in the 2019 450 MX Shootout.
Video By: Bert Beltran
Before we began the test, we mounted a Dunlop D404 street tire on the rear wheel and ran the KX450 on our in-house Dynojet dynamometer, where it produced 51.96 hp at 9,310 rpm and 32.30 pound-feet of torque at 6,900 rpm. With these figures, the Kawasaki ranks second in horsepower and fifth in torque among the six bikes in the test. After the dyno runs were complete, we put on a fresh set of Dunlop’s all-new MX33 soft-to-intermediate-terrain tires to ensure consistency in traction among the six competitors through the duration of our test.
The powerband is very usable as the engine is free-revving and has plenty of torque. The bottom-end is excellent—not too strong to where it feels jerky, but more than enough to be comfortably lugged in a higher gear. The KX has great top-end and over-rev, which makes it easy to carry a gear for a long time before needing to shift.
Three color-coded couplers allow riders to tweak engine mapping for track conditions. The green coupler is a good stock setting as it has an even power curve but could use a little more pick-up. The white coupler revs quicker and works best when the conditions are deep and loamy, usually at the beginning of the day. The black coupler does not rev out as quickly, making the power delivery very manageable and easier to ride when the track becomes more run-in and hard-packed.
The Nissin hydraulic clutch works great with a light lever feel that’s easy to modulate. The engine shifts smoothly and the gearing is good, too. The muffler sticks out pretty far, which is a small price to pay for how pleasantly quiet the bike is.
The stock settings on fork and shock are very good. Each test rider made very few, if any, changes over the two-day test, and those who did found the setting they were looking for with one or two adjustments. The fork has more of a comfort-oriented feel, which is partially due to a soft spring rate. Heavier test riders occasionally bottomed the fork on really big impacts, a problem that could be alleviated with stiffer springs. The valving is great and fork action is very progressive. Aside from the occasional hard landing, the front end soaks up everything from small braking bumps to most large hits with plenty of comfort and predictability. The shock is well-matched to the fork, and at 105mm of sag, the bike feels balanced. It stays planted in rough conditions and holds up well on impacts.
The KX450 chassis not only retains the same agreeableness as last year but offers further improvements. It’s remarkably narrow from front to rear, especially in the radiator shroud area. It’s the slimmest-feeling bike in the class, has a very roomy cockpit area, and a flat seat, all of which make it easy to move forward and back on while riding.
The Kawasaki came in at 246 pounds on our automotive scales, which makes it the third lightest bike in the shootout and the lightest Japanese motorcycle in the test. The KX450 turns well and is more of a front-end-steering bike than it’s ever been, yet it retains its confidence-inspiring stability. Overall, the ergonomics are very agreeable. The stock Renthal 971-bend handlebar is a bit high; we’d opt for a bar with less rise or the same bar with lower mounts.
Why It Won
The KX450 has just about the perfect balance of everything. It has a powerful engine, very good suspension, a narrow chassis that is stable and corners well, and agreeable ergonomics.
Why It Shouldn’t Have Won
The muffler sticks out far and the stock handlebar position is a bit high.