Kawasaki KX450F 2027 Test: The New Motocross Beast

Test and report: Jonas Ederer

Kawasaki presented the new KX450F at the media launch at Rocco's Ranch near Barcelona. The update for model year 2027 is more extensive than it looks at first glance: new airbox, new exhaust, revised chassis, Brembo brakes and significantly expanded electronics with app connectivity. According to the presentation, this makes the KX450F more of a race bike than ever. I was able to find out for myself whether that's true on a demanding 1.8-kilometre track with 17 jumps. Among other things, the track featured a 45-metre triple, a pyramid, a doubles section and a fast passage in third and fourth gear. In other words, the perfect playground for a 450!

The biggest changes concern the engine. Kawasaki has redesigned the intake duct, airbox, header pipe and silencer. The intake port has become narrower. This improves low-rpm response and delivers more power at high revs. The air filter has 29 percent more surface area, is more resistant to sand ingress and reduces intake noise. The injector now sits at an angle of 90 instead of 40 degrees to the throttle body. On top of that comes a revised ECU setup. The goal is a stronger feeling of torque and more direct throttle response.

A revised frame provides more agility, a new swingarm more traction at the rear wheel. The silencer is no longer conical but straight. With the same volume, it is 300 grams lighter, meets the stricter 2027 noise regulations and gives a sportier look. Kawasaki has also worked on the chassis: • The new subframe made of high-strength materials saves 200 grams. • The swingarm has a reshaped cross-section for optimised stiffness. • Two additional chain links (116 instead of 114) move the rear axle 5 millimetres back. As a result, the wheelbase grows from 1,480 to 1,485 millimetres. • The 49-millimetre Showa coil-spring fork is 350 grams lighter and has new internals with smaller damping pistons. • The upper shock mount has been reshaped for more stiffness. The braking system now comes entirely from Brembo. Up front with a braided steel line and a 270-millimetre disc from Sunstar. At the rear, Kawasaki fits a Brembo master cylinder and caliper with a 240-millimetre disc to a 450 mx bike for the first time.

The bodywork has become more compact. The radiator shrouds have a new shape for better ergonomics, and the seat has been given a grippier material. The handlebar can be mounted in four positions (standard, 25 millimetres forward, 15 millimetres forward, 10 millimetres back) and is rather narrow as standard. As usual with Kawasaki, the footpegs can be set in two positions (standard or 5 millimetres lower). A Renthal Fatbar handlebar, ODI Lock-On grips and Dunlop tyres (MX34F front, MX34 rear) are fitted as standard. On durability and quality, Kawasaki cites figures from racing: as world champion, Romain Febvre contested all 20 Grands Prix in 2025 and all 19 in 2026. In 2026 he finished 37 of 38 motos, with only one moto in Spain ending early due to a crash.

New is control via the "Rideology The App KX2" app. The connectivity features include a factory-fitted GPS unit on the bike, which can be paired with a smartphone and has been neatly integrated into the front fender. The app offers five mappings ranging from Mild to Aggressive. Two freely configurable memory slots allow fuel injection quantity and ignition timing to be adjusted individually. Switching between two mappings is done via a button on the handlebar, which doesn't always respond on the first press. The traction control (KTRC) also has two modes and can be switched off completely. In the app, the intervention level can be set to Low, Standard or High. There's also a three-stage launch control with adjustable rev limit, activated by pressing both buttons simultaneously. The app also offers monitoring, allowing the condition of the bike to be checked at any time. To check the GPS function, it displays the position of the connected bike. On top of that come an hour meter, a manual for suspension and fuel injection setup, and trip logs for ride analysis.

Engine: The engine is aggressive, but in a pleasant way. The rev range is very linear. Power comes in smoothly, and engine braking is low. Kawasaki promises more bite at the bottom end and a better midrange, and that's exactly the character I found pleasantly aggressive. Vibrations are noticeable, though.

Electronics: Of the two mappings, I preferred the less aggressive one. The traction control, especially early on in muddy conditions, is clearly noticeable but doesn't intervene too much. A positive side effect: it helps against arm pump.

Suspension and handling: The suspension is pleasantly responsive initially and then becomes progressively firmer, which I liked. In the corners, the KX450F shows its agile side. The balance is largely neutral; on take-off, the bike feels rather rear-heavy. With the 5-millimetre longer wheelbase, Kawasaki is aiming for more stability. Even so, I still felt a slight headshake on the straights.

Ergonomics: Around the tank, the Kawi feels very slim, and I like that. In the middle and rear section, the Kawasaki is a bit wider. There I had a good feel and good grip with my legs. In the seating position, you get the impression that either the seat is low or the handlebar is high. Its position can be adjusted in four steps, and once set to personal preference, the position fits much better.

Clutch and brakes: The hydraulic clutch does its job unobtrusively. The Brembo brakes work at the usual high level. Only the rear brake showed noticeable heat build-up. Details: The airbox opens easily without tools, and the filter is simple to change without any fiddling. An insert that alters the air intake can easily be fitted, thereby influencing the Kawi's torque.

Also available as the KX450FX

For cross-country use, there's the KX450FX with the same engine, the same chassis and the same technical updates. It differs in its 21-inch front and 18-inch rear wheel combination, Dunlop EN91 enduro tyres, adapted spring rates and damping, and a side stand. This makes it an alternative for cross-country races and classic enduro races where road registration isn't required.