2021 Kawasaki KX450X

A bike that shares so many similarities with Dirt Rider’s 2019, 2020, and 2021 450 Motocross Shootout winner and has minor tweaks for off-road racing is inevitably going to be a solid option.

A new model to Kawasaki’s lineup for 2021, the KX450X is Team Green’s flagship cross-country motorcycle. Intended to slalom through the trees of GNCC and power across the more wide-open terrain of the WORCS series, the KX450X is designed to tackle just about anything you can throw at it in terms of off-road riding and has plenty of motocross prowess in its DNA as well.

Being that 2021 is the first year the KX450X has appeared on the market, it is a new model, but it shares many of the same components as the KX450. Some of the differences between the KX450X and its motocross-focused counterpart are that it has softer spring rates and different valving in the Showa 49mm coil-spring fork and Showa shock, an 18-inch rear wheel, one-tooth-larger rear sprocket, and a kickstand.

At $9,599, the Kawasaki KX450X is the least expensive 450 cross-country model on the market and as much as $1,200 under the pricier options like the KTM 450 XC-F and Husqvarna FX 450.

A 449cc, DOHC, liquid-cooled engine is housed inside the KX450X’s aluminum perimeter frame. Although we haven’t run the KX450X on our dyno, the KX450 motocrosser, which shares an identical engine, churned out 52.4 hp at 9,600 rpm and 32.6 pound-feet of torque at 7,000 rpm. Dirt Rider test rider Allan Brown is a fan of the KX450X’s powerplant, stating it is “user-friendly and enjoyable to ride. It comes on nice with a reasonable amount of hit, has good midrange grunt, and runs out just long enough so that you don’t have to shift before the next corner.”

The KX450X’s neutral-handling chassis is complemented by its peppy engine character, which makes the entire bike feel lively, while its softer suspension setting gives it a more planted feel than its motocross sibling.

Although it has off-road-specific front brake pads, the KX450X’s braking feel and power is unsurprisingly similar to the KX450. The Nissin units on the green machine work well, but aren’t as powerful as the Brembo components on the KTM and Husqvarna or as progressive as the Nissin brakes on the Yamaha.

Claimed or measured mpg information is not available, but we can say that if you want to go on a considerable trail ride (30 miles or longer), you’ll either want to carry gas or purchase a larger-capacity aftermarket fuel tank from a company like IMS Products because the KX450X’s 1.6-gallon unit is the same one that comes on the motocross model and is in no way sufficient for lengthier rides.

A slim radiator shroud area, narrow midsection, flat seat, and excellent rider triangle give the KX450X some of the best ergonomics of any bike on the market. Kawasaki’s flagship cross-country model also offers the most ergonomic adjustability in the class with its adjustable footpeg and handlebar position.

Kawasaki is the only one of the Big Six manufacturers in the 450 cross-country dirt bike market not offering a handlebar-mounted electronics suite to adjust the EFI mapping. Instead, Team Green has three color-coded EFI couplers—black (mellow), green (standard), and white (aggressive). The couplers make a noticeable difference and can be tuned using the KX FI Calibration Controller, which is available for purchase as an accessory for $699.95.

A warranty is not available for the 2021 Kawasaki KX450X.

The plastics on Kawasaki’s motocross and cross-country models look a bit more weathered after about 20 hours of use compared to other bikes in the class and the small bolts like those used for the plastics and number plates are a little flimsy by comparison to the competition as well. Aside from that, the fit and finish of the KX models is solid. Also, reliability on the models has improved this year with Kawasaki’s new coned disc-spring clutch, which increases the component’s service life.