2024 Kawasaki KX450, KX450X AND KX 50th Anniversary Edition Motorcycles

Over the last 50 years, the Kawasaki KX brand of motorcycles has helped pave the path to championships for the some of the most popular motocross racers of all time. Today, the KX family remains one of the most dominant motocross and supercross brand of motorcycles available, with the all-new KX450 once again raising the bar. With development cues taken from the Monster Energy Kawasaki factory racing team, the all-new 2024 KX450 is one of the strongest and most race-ready machines on the dirt. To commemorate the celebration and success of 50 years of the KX brand, Kawasaki is pleased to announce the release of 50 Anniversary Edition motorcycles. Equipped with a limited retro-inspired KX shroud graphic, a Uni-Trak swingarm graphic, blue seat, silver wheels and white fork guards, the 2024 KX250 50th Anniversary Edition and the KX450 50th Anniversary Edition motorcycles will spark nostalgia and tug at the heartstrings of motocrothss enthusiasts across the globe.

All-New 2024 Kawasaki KX450 Highlights

Engine tuning
Cylinder head
Straight exhaust port and center exhaust
Smartphone connectivity via RIDEOLOGY THE APP KX*
Handlebar-mounted traction control switch
Brembo brake system
Lightweight aluminum perimeter frame
ODI Lock-On grips
Easy-to-remove side cover
Slim ergonomic bodywork
Kawasaki TRaction Control and riding modes

Engine

The KX450 engine has always been recognized for its strength and torque character, and the lightweight engine package is even stronger in 2024. The four-stroke, single-cylinder, dual-overhead camshaft (DOHC), liquid-cooled 449cc engine has increased engine performance thanks to a new downdraft intake and symmetrically aligned intake and exhaust. The redesigned intake increases the downdraft angle from 20 to 40 degrees for a straighter, more direct route for air and fuel to enter the cylinder and increasing the cylinder-filling efficiency. The centrally positioned exhaust port aligns with the intake for more efficient airflow and more engine power.

With the new intake and exhaust design, Kawasaki changed the throttle body layout to optimize intake efficiency, resulting in smooth power delivery and quick engine response even when given partial throttle. The increased fuel pump pressure helps to increase rideability, and with cues taken from Kawasaki’s WorldSBK engineers, the valve train of the KX450 features finger-follower valve actuation. This allowed the use of large-diameter valves and more aggressive cam profiles, resulting in higher rev limits and strong high-rpm performance. Thirty-eight-millimeter intake valves help optimize the feel of the new engine, and diamond-like carbon (DLC) coating on the finger followers helps to reduce friction and wear.

A high-performance piston, featuring the same design used by the Monster Energy Kawasaki team, contributes to increased performance across the entire rpm range. A short skirt, reinforced external ribs and the use of a bridged-box bottom with internal bracing adds to the light but strong piston design. A thicker piston top ring was added to match the increased power output from the engine, and the cylinder was placed 8.5 millimeters forward to help reduce friction. The connecting rod was extended by 5 millimeters to help further reduce friction, and the cylinder height and crankshaft were updated to match the new length.

The oil jet angle was also changed to match the longer connecting rod, resulting in increased power.

A new center-port exhaust allows a relatively long header pipe to be maintained for robust low-end power thanks to the pipe exiting the center of the cylinder head and traveling through the frame cradle instead of to the side. With the exhaust header end moved forward, the muffler was also moved forward to help centralize mass. The muffler end is almost 3.5 inches further forward compared to the 2023 model. A flatter-shaped exhaust resonator chamber, which effectively increases exhaust pipe length and reduces exhaust noise, has been moved just over two inches inward for less interference with the rider’s leg. The new position also contributes to an easier ground reach, which is especially helpful when on the starting line.

The KX450 retains a hydraulic clutch, offering a more direct feel and less play for the rider. Coned-disc spring contributes to light clutch actuation when pulling the lever in while allowing for a wider clutch engagement range. Friction plates are offset and slightly rotated to help maintain a clean separation of the discs and help reduce drag when the clutch is engaged.

An electric start allows for a quick engine startup and is activated by the push of a button located on the handlebar near the right grip making starting easy and convenient. A lightweight, compact lithium-ion battery helps keep weight down, as does an automatic centrifugal decompression system fitted to the exhaust cam, which lifts one exhaust valve to facilitate starting.

Electronics

Marking another first for the KX brand, riders can now select power modes using a Power Mode (M) selection button located on the left side of the handlebars, replacing the DFI couplers from the previous model. Riders can easily switch between two pre-programmed engine maps (Normal and Mild). The Normal map allows the rider to utilize the full power of the engine, while the Mild map reduces the power for scenarios where full power is not needed.

For the first time on a KX motorcycle, riders will now be able to connect to their motorcycles using RIDEOLOGY THE APP KX.* Users will be able to adjust their bikes’ engine maps to match riding conditions and monitor what the KX450 is doing based on real-time data. Riders can also record and save maintenance and setup logs within the app.

The 2024 KX450 is the first KX model to offer Kawasaki TRaction Control, technology found on many Kawasaki street motorcycles. Using the Traction (T) button on the left handlebar, riders can quickly select between two levels of assistance (Low and Strong) based on riding conditions and preference. The engine control unit (ECU) settings help to enhance traction by retarding the ignition when the rear wheel speed increases too quickly. Riders also have the ability to turn this feature off when not needed.

Getting ahead of the competition right out of the gate is imperative to racers, eliminating the grueling task of fighting through the pack. Similar to the system that the Monster Energy Kawasaki team utilizes, the factory-style Launch Control Mode comes standard on the KX450, giving riders the tools needed for efficient race starts in lower-traction conditions. Riders can easily activate Launch Control by pushing the Mode (M) and Traction (T) buttons simultaneously.

*RIDEOLOGY THE APP KX is not intended for use during vehicle operation. Only use RIDEOLOGY THE APP when the vehicle is not being operated and it is safe to do so.

Chassis

Kawasaki’s engineering team has worked hard to develop an industry-leading slim aluminum perimeter frame that is capable of accommodating the updates to the engine’s intake and exhaust while maintaining light, nimble handling and a composed character. As an evolution of the current design, the new frame boasts an optimized rigidity balance, which allows for improved cornering performance across a wide range of conditions. The frame’s lightweight construction is composed of forged, extruded and cast parts, while the engine is used as a stressed member and adds to the frame’s rigidity balance.

Several revisions were made to the frame components to contribute to the rigidity balance including the Y-joint shape and position, upper cross-pipe shape, swingarm bracket shape and lower cross-pipe cross-sectional shape. With the new downdraft intake layout, the upper cross pipe was moved downwards so the intake could be routed above it. The lower cross pipe was moved downwards, and the rear shock mounting position were moved to match. The downtube’s Y-joint was moved 125 millimeters higher to make room for the new exhaust. Further adding to the frame’s rigidity balance is the engine, which is used as a stressed member. The revised torsional rigidity increases the front-end feel while a rider is cornering, allowing for a more planted feel and more consistent performance. The swingarm rigidity is matched to the frame and helps contribute to rear wheel traction.

The chassis balance and settings were all developed with the racer in mind. The bike’s center of gravity and dimensions were all selected so the rear tire would drive the bike forward instead of causing it to squat.

Suspension and Brakes

The braking package on the KX450 receives numerous high-grade components for 2024, including drilled petal disc brakes from the world-renowned Braking/Sunstar brand. For the first time in history, a Brembo caliper and master cylinder will adorn the front of a KX bike, encompassing a large-diameter, semi-floating 270-millimeter front disc. This new combination results in strong front braking and increased front-end stabilization, allowing the rider to carry more speed through corners. At the rear, a 240-millimeter disc gripped by a Nissin caliper offers the perfect balance of power and controllability.

A new, thicker front brake lever will be utilized on the 2024 KX450, allowing the rider to more easily grip the front brake and maintain more precise brake control.

The KX450 motorcycle is equipped with high-performance Showa 49-millimeter coil spring front forks, which feature large diameter inner tubes that are the same size as those found on Kawasaki’s factory racing team’s bikes and enable the use of large damping pistons for smooth action and firm damping. A hard coating on the outer surface of the fork inner tubes helps prevent wear abrasion. The increased surface hardness coating also helps to prevent scratches and damage to the tubes. As a result of the surface remaining smoother for a longer period, the reduction of friction creates a smoother and more enjoyable ride. Incredibly precise personalized settings can be found with fully adjustable compression and rebound damping. The fork’s interval timing, adjusters and oil level were fine-tuned to deliver the best settings possible for the new model.

On the rear suspension, a Kawasaki New Uni-Trak linkage system is designed to work in conjunction with the new shock, new aluminum frame and new swingarm. The linkage, which is mounted below the swingarm, allows for a longer rear suspension stroke and allows more precise rear suspension tuning. To accommodate the new intake, the shock unit is 32 millimeters shorter (486 millimeters reduced to 454 millimeters), and the shock’s reservoir tank has been moved to the left side of the motorcycle, allowing more room for the exhaust pipe. Dual compression adjustability can be found on the rear shock, allowing high-speed and low-speed damping to be adjusted separately. The fully adjustable shock allows for settings to be personalized for riding preference and conditions. Like the front forks, the rear shock’s internal valving, adjusters and gas pressure were optimized to allow for the best performance possible.

Wheels and Tires

Developed with help from the factory race teams, the KX450 now features a larger-diameter rear hub, increasing 12 millimeters in size (46 millimeters to 58 millimeters) and increasing the hub’s overall rigidity, allowing for greater rear-end traction. The front wheel is fitted with the new Dunlop MX34 80/100-21 51M tire, which features a new block pattern that increases longevity and improves contact with the ground. A new Dunlop MX34 120/80-19 rear tire offers more bump absorption and increased traction on the back wheel.

Ergonomics

Already known for its slim profile, the engineers of the 2024 KX450 took it a step further and redesigned a majority of the bodywork, offering a smoother rider interface than ever before. Newly designed shrouds, seat, side covers and rear fender allow the rider to move more confidently on the motorcycle. The seams between the shrouds, seat and side covers sit flush and the shroud design is slightly wider but offers a more gradual taper for smoother rider movement. The tops of the shrouds curve in to eliminate any hooking points, and with the rear shock reservoir now located on the left side of the bike, the revised side cover now creates a fuller surface area for the rider to grip. A new quick-release side cover eases the process of accessing the air filter, which can now be removed without tools, and the air filter itself is now held in place using quick-release hooks.

Riders will notice more hand comfort with the addition of medium-compound ODI Lock-On grips, which offers an excellent grip feel and eases the process of changing grips with its screw-type fastening system. The grips adorn a factory-style 1.125-inch Renthal aluminum Fatbar which helps reduce vibration and harsh impacts felt on the rider’s hands and arms. The upper triple clamp has two sets of handlebar mount slots and reversible handlebar mounts, offering riders a choice between four handlebar positions: 25 millimeters forward, 15 millimeters forward, standard and 10 millimeters backward.

The KX450 cannot be mistaken for anything but a Kawasaki racing machine, receiving the all-over Lime Green treatment for 2024. All of the bodywork elements, from nose to tail, are the classic Kawasaki Lime Green color, with a green seat cover completing the look. The front fork guards have been changed to Lime Green to match the racing aesthetic, and a shorter rear fender design helps complement the new silencer position. Matching the factory racing team, the rims are coated in a black alumite and the fork and rear shock adjusters are finished with a high-quality green alumite. A gold finish on the oil cap and plugs ties the bike’s KX racer looks together, making for an eye-catching machine that is sure to garner attention on the track.

Racer Rewards

Kawasaki Team Green Racer Rewards for 2024 supercross, motocross and off-road racing will be available for riders looking to race their KX motorcycles. For more information and to register, visit the Racer Rewards section on Kawasaki.com.

KX450X

Returning alongside the KX450 is the all-new KX450X, helping to further expand and solidify the KX family of off-road motorcycles. With the strength, power and all of the new features of the all-new KX450 behind it, the KX450X makes every off-road adventure exciting and fun. Off-road potential is greatly increased thanks to the technical updates the KX450X received, with cross-country specific tuning on the suspension, 21/18-inch wheel combination with off-road ready tires. The KX450X is truly a cross-country competitor’s best choice.

All-New 2024 Kawasaki KX450X Highlights

Includes all of the new features found on the KX450, plus:

Front and rear tires
Engine tuning
Suspension settings.

The 2024 KX450X is an off-road cross-country competition model that features the same championship-proven technology found on KX race machines and has been purposely tuned for off- road competition. The addition of an 18” rear tire allows the power of the KX450X to be transferred directly to the ground and the Dunlop AT81 tires make sure the bike is capable of handling the obstacles found in cross-country riding. A high-performance 49mm inverted coil-spring fork and New Uni Trak rear suspension are inherited from its KX450 brethren, with the spring rates and damping settings optimized for the cross-country environment. The KX450X also comes with a convenient side stand for stopping.