2024 Kawasaki KX450 Extended Test [14 Fast Facts]

May 22, 2024

It’s always exciting when a new generation model comes out. Of course, we all wonder how it will compare to the previous generation and how it will compete with the rest of the class. This year, Kawasaki went all in on redesigning the KX450 platform, giving it a new motor and chassis design. We also see upgraded electronics and new components in the 2024 Kawasaki KX450 mix. I’ve clocked over 10 hours of ride time and tested the KX450 on various tracks in many kinds of dirt, so let’s talk about what I discovered.

Kawasaki finally makes a motocross bike that wants to turn. Traditionally, the KX models offered a stable, upright handling style, making it harder to control in the turns. I have always had a love/hate relationship with the KX chassis. I loved the high-speed stability, but always struggled in the turns. I’m happy to report that the all-new 2024 Kawasaki KX450 chassis is completely redesigned to offer more aggressive turn-in while maintaining high-speed stability.

The new chassis design differs drastically from previous KX models, as the front end is now very nimble. Although I like the change, it does come with some sacrifice. While the new chassis maintains high-speed stability, there can be noticeably more head shake in rough conditions, and it almost wants to oversteer in the corners. Due to the newly nimble handling and easy-to-turn front end of the new KX450, the rider will have to make riding style adjustments.

I have some solutions to improve the front-end behavior. I set my sag at 102mm and lowered the fork height from the factory position by 1mm. Initially, I set the KX450’s sag at 105mm, but that was too much for me, as the rear end felt heavy and sluggish. Setting the sag at 102mm worked perfectly. I also stiffened the fork compression by a few clicks to prevent the front end from dipping too much in the corners. Together, these changes added more front-end stability, especially in rough conditions. While your settings may differ, you get the idea—it all depends on your weight, height, speed, and track conditions. These minor adjustments were made trackside, and I encourage riders to test new settings. Even minor adjustments can make a big difference in handling, and the right ones can dramatically increase rideability.

The comfort and rideability is also due to the new Showa suspension system. The large-diameter inner tubes are the same size as found on the Monster Energy Kawasaki factory racing team, enabling the use of large 25mm damping pistons to deliver smooth action and firm damping. The new fork’s internal valving, adjusters, and oil levels were fine-tuned to provide optimized settings for the 2024 KX450. The free piston was shortened to increase responsiveness, and a new O-ring material reduces friction by a claimed 80 percent. Less friction superior fork action.

The Showa shock had to be redesigned to accommodate the downdraft intake system. The new Showa shock is 32mm shorter than last year while maintaining the same stroke. Also, the shock reservoir is moved to the left side of the motorcycle. Although the reservoir is hidden behind the rear left-side plastic, it can easily be accessed with a tool for adjusting high-speed and low-speed compression damping.

Moving on to the power package, the new KX450 motor is a topic for debate. I’m sure there will be lovers and haters on this new motor package. Why? Because the power delivery is so smooth and linear that it deceivingly feels slow. However, I assure you it is not slow. It’s a 450, and there’s nothing slow about a 450. Yes, the 2024 KX450’s output above 7k or so is down a few horses compared to most of the competition. While Experts and Pros might be able to tell the difference between 56 and 53 horsepower when the motor is spun up over 9k, the rest of us usually aren’t running the engine in that rpm range.

I can ride the 2024 Kawasaki KX450 much like a 250. The power is so linear and controllable that I can be aggressive on the throttle and never feel intimidated or out of control. I can hold the throttle wide open on the 2024 KX450 as I exit the corners like I would on a 250, yet feel in total control. That is due in equal parts to the smooth power output and the stable chassis.

Kawasaki has developed a new smartphone app called Rideology The App for personalized tuning. A new communication unit mounted on the left rear frame rail enables riders to wirelessly connect the app to the KX450. Application features include FI Calibration, Engine Monitoring, Maintenance Log, and Setup Log. Using the app’s six-by-six grid interface, fuel volume and ignition timing of the bike’s two original maps can be fine-tuned to suit the conditions and rider preferences.

Engine monitoring is a cool Rideology feature. While the engine is running and the app is connected to the bike, the engine rpm, throttle position, engine intake pressure, coolant temperature, air temperature, and ignition offset can be viewed in real-time. For those do-it-yourselfers, Rideology includes a maintenance log where memo-style maintenance logs can be recorded to keep track of your maintenance intervals.

Of course, with all the fancy electronics, Kawasaki introduces a map selection switch mounted on the left side of the handlebars. Say goodbye to the snap-in couplers to change maps. The rider can easily select between two maps by pressing the map switch. If you see a blue light, you’re running the mellow map; if no light is showing, the KX450 is using the standard map. When you fine-tune the original maps within Rideology, map 1 (light off) will always be the more aggressive map, while map 2 (blue light on) will always be the mellower setting.

I experimented with both the maps and traction control. The standard map with traction control off is an excellent setting for the smooth track and perfect dirt condition days. The mellow map works when the motocross track is rough and beat up. Glen Helen Raceway gets extremely dry and sandy in the afternoon when the sun has baked the dirt. It can also get hard-packed under the loose sand, causing a lot of wheel spin. The traction control works superbly in those conditions—especially on the uphills. I haven’t had the chance to ride the 2024 Kawasaki KX450 in slick, muddy conditions; should that happen, I assure you I will be on Map 2 (mellow) with traction control on.

The Brembo front brake system and the Nissin rear brake system pair well. Although I would like to see a matching brake set just for feng shui purposes, the brakes felt pretty good. The Brembo brake lever requires more pull to find a good stopping feel, something I’ve always found true with Kawasaki front brakes. The front brake feels soft at the initial pull of the lever, and you have to pull hard to get good stopping power. The rear Nissin braking system has good feel and more initial stopping power.

The 2024 Kawasaki KX450’s all-new bodywork is functional and fashionable. It’s Functional because Kawasaki eliminated a lot of hook points throughout the bodywork by adding surface area and smoothing transitions. The shrouds are exceptionally narrow and smoothly transition from back to front. Also, if you examine the plastics closely, you’ll discover that the edges are beveled to eliminate any chances of snagging your riding gear. The added surface area is also great for added grip on the motorcycle. More grip between your legs means more overall control. I also say fashionable because it just looks good! The overall smooth and even bodywork just looks sharp, and who doesn’t like a nice-looking motorcycle?

So what category do I fall into, Lover or Hater? Okay, hate is a strong word. I don’t think anyone can hate on a KX450, and I’m a lover. Kawasaki R&D decided to put out a 450 that appeals to all rider levels, with a focus on the average rider. The new KX450 is a very controllable 450. It has plenty of power and smoothly delivered low-rpm torque. Power develops linearly through the midrange, and keeps pulling strongly through the overrev. Combine that power delivery with a stable chassis and plush suspension, and you have a recipe for a comfortable ride. So, if you’re a rider looking for the fun factor and overall controllability, the 2024 Kawasaki KX450 platform is the bike for you.

Action photography by Don Williams
Static photography by Will Embree/SMX Pictures

RIDING STYLE

Helmet: Arai VX-Pro4 Resolute Yellow

Goggles: Oakley Airbrake

Pants + jersey: Just1 J-Flex 2.0

Gloves: Just1 J-Flex 2.0

Chest protector: Alpinestars Bionic Action V2

Compression shorts: Ethika

Knee braces: Alpinestars Bionic-10 Carbon

Boots: Alpinestars Tech 10

2024 Kawasaki KX450 Specs

ENGINE

Type: Single-cylinder four-stroke
Displacement: 449cc
Bore x stroke: 96.0 x 62.1mm
Starting: Electric
Fueling: EFI w/ 44mm Keihin throttle body w/ dual injectors
Transmission: 5-speed
Clutch: Hydraulically actuated wet multidisc w/ coned-disc spring
Final drive: Chain

CHASSIS

Frame: Aluminum perimeter
Handlebar: Renthal Fatbar
Front suspension; travel: Compression- and rebound-damping adjustable Showa 49mm inverted fork; 12.0 inches
Rear suspension; travel: Linkage-assisted fully adjustable Showa piggyback reservoir shock; 12.1 inches
Tires: Dunlop Geomax MX34
Front tire: 80/100 x 21
Rear tire: 120/90 x 19
Front brake: 270mm Braking disc w/ Brembo caliper
Rear brake: 240mm Sunstar disc w/ Nissin caliper

DIMENSIONS and CAPACITIES