To maintain its edge in this fiercely competitive class, the 2020 KX450 benefits from an engine mounted in its leanest chassis to date, enabling it to turn even quicker lap times, and make it the most powerful machine in the paddock. Complementing its already high performance, with a number of features - including finger-follower valve actuation, electric start and a hydraulic clutch, - further elevate its race-winning potential.
Designed with mid-level to expert riders in mind, the KX450 motorcycle has always been built with one goal in mind: to put riders on the top step of the podium. And for over 40 years KX brand motocrossers have been extremely successful at doing just that.
Kawasaki's hydraulic clutch on a motocrosser offers more direct feel and lighter lever action. Less play as the clutch heats up during heavy use results in more consistent feeling.
LIGHT WEIGHT & LIGHT, NIMBLE HANDLING
Complementing the powerful engine, light, nimble handling contributes to the KX450's quick lap times. With the electric start and the coil-spring fork The KX450's lean chassis, and a highly-competitive, low overall weight of only 110.0 kg.
Increased front and rear traction ensure the bike can put power to the ground and get around corners quickly. A large-diameter front axle (a hint from our racing teams) helps at the front, while rear suspension layout and linkage ratios benefit the rear.
Being able to restart an engine quickly during a race can mean the difference between keeping your lead, or having to fight your way back through the pack. Kawasaki's electric start on a motocrosser makes restarting the engine as easy as pushing a button. Starting is electric only, via a button located on the right grip.
LARGE-DIAMETER COIL-SPRING FORK
Handling suspension duties up front is a high performance 49 mm inverted coil-spring fork. The large diameter inner tubes (the same size as on our factory racers) enables the use of large damping pistons, delivering smooth action and firm damping. A super-hard titanium coating on the outer surface of the fork inner tubes helps prevent wear abrasion. The increased surface hardness of the dark navy blue coating also helps to prevent scratches and damage to the tubes.
KASHIMA COAT FORKS
Kashima Coat creates a hard, low-friction surface on the outer tubes. The hard coating helps prevent wear abrasion on the inside of the tubes, ensuring the sliding surfaces remain smooth for a long time, while on the outside is protected against corrosion and for a factory appearance. The lubricating material in the coating contributes to smoother suspension action (especially at the initial part of the stroke) and a better ride feel.
LIGHTWEIGHT, ALUMINIUM PERIMETER FRAME
An evolution of design, the frame features includes the engine as a stressed member. The swingarm also contributes to the rigidity, balance and rear traction of the KX450.
DOWNDRAFT INTAKE & LARGE THROTTLE
Downdraft-style intake routing allows an even straighter approach for intake air. The intake air's approach angle into the cylinder is 20Â°, improving cylinder filling efficiency and contributing to increased engine power. Large-diameter (Ã¸43 mm >> Ã¸44 mm) - it turns in the opposite direction to open - flows a greater volume of air, contributing to increased performance - especially at high rpm and over-run - and driveability.
ADVANCED ENGINE DESIGN
The finger-follower valve actuation reduces the valve train mass (IN is 4.2% lighter; EX is 7.9% lighter) compared to a tappet-style valve actuation (even taking into account larger-diameter valves). DLC (Diamond-Like Carbon) coating on the finger followers helps protect against wear. Complementing more aggressive cams, large-diameter intake 40 mm diameter and exhaust valves 33 mm diameter with increased lift flow more air, contributing to the increased power. The camshafts benefit from a thin and highly durable gas-nitriding treatment for long wear and high-rpm reliability. Valves are formed from lightweight titanium, reducing reciprocating weight and offering high-rpm reliability. SCr (chromium steel) valve spring retainers contribute to increased reliability at high-rpm.
HIGH PERFORMANCE ENGINE
High-performance piston, featuring the same design used on our factory racers, contributes to strong performance at all rpm. A short skirt, reinforced external ribs and the use of a bridged-box bottom, featuring internal bracing, contributes to a light, strong piston design. This design and strength optimisation results in a light piston (259.8 g >> 243 g), reducing reciprocating weight and contributing to the engine's performance. With needle bearings to the connecting rod big-end, reduces mechanical loss, contributing to overall performance.
With a long header pipe (590 mm >> 695 mm) contributes to increased low end power and torque.
UNI-TRAK REAR SUSPENSION
The Uni-Trak rear suspension system mounts the suspension arm below the swingarm, allowing a longer rear suspension stroke. The longer stroke in turn allows more precise rear suspension tuning. Linkage ratios contribute to increased rear wheel traction. The rear shock features dual compression adjustability, allowing highspeed and low-speed damping to be tuned separately. A self-lubricating alumite coating on the tank cylinder helps prevent wear abrasion, and reduces friction for smoother suspension action.
4-stroke, liquid cooled, single cylinder
Bore x Stroke
96.0 x 62.1 mm
DOHC, 4 valves
Fuel injection: ø43 mm x 1
Wet multi-disc with Brembo hydrualic operation
Wheel travel - front
Wheel travel - rear
Suspension - front
49 mm inverted telescopic spring fork with adjustable compression and rebound damping
Suspension - rear
New Uni-Trak with adjustable dual-range (high/low-speed) compression damping, adjustable rebound damping and adjustable preload
Brakes - front
Single 270 mm semi-floating petal disc with dual piston caliper
Brakes - rear
Single 240 mm petal disc with single piston caliper
L x W x H
2,195 x 820 x 1,280 mm
108.8 kg (includes full fuel tank, all fluids at optimum levels)