Motocross Bikes
2021Kawasaki KX450X
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The 2021 Kawasaki KX450X is a competitive motocross bike designed for amateur and professional riders seeking a lightweight, agile machine. Its 449cc liquid-cooled four-stroke engine with DFI fuel injection delivers strong midrange power and predictable handling characteristics. Best known for excellent cornering stability and reliable performance across varied terrain, the KX450X remains a popular choice for cross-country and off-road competition.
- Capacity
- 449.0 ccm
- Engine
- Single, four-stroke
- Gearbox
- 5-speed
- Dry weight
- 107.0 kg
- Seat height
- 950 mm
- Power
- 56.0 HP (41.2 kW)
How it rides
Editorial estimate from the spec sheet - not lab tested- Best for
- Built specifically for cross-country and off-road racing, with a wide-ratio gearbox, larger fuel capacity, and chassis geometry tuned for extended off-road stability rather than motocross jumps or street use.
- Built for
- It has the raw, high-strung, minimalist character of a purpose-built race bike: light, responsive, and demanding rather than forgiving.
- Not ideal for
- This is not a suitable choice for commuting, highway touring, carrying a passenger, or riders seeking plush comfort and low-maintenance road-going practicality.
Scores are derived from the spec sheet using the same model across every bike, so they compare like for like.
Will it fit you?
Worked out in your browser - nothing is sent to usEngine
- Capacity
- 449.0 ccm
- Power
- 56.0 HP (41.2 kW)
- Engine type
- Single, four-stroke
- Power/weight ratio
- 0.5234 HP/kg (dry)
- Bore x stroke
- 96.0 x 62.0 mm
- Compression
- 12.5:1
- Cooling system
- Liquid
- Fuel system
- Injection
- Starting
- Electric
- Ignition
- Digital CDI with 3 Coupler Options
- Lubrication system
- Forced lubrication, semi-dry sump
Transmission
- Gearbox
- 5-speed
- Transmission type
- Manual
- Clutch
- Wet multi-disc, manual
Dimensions & weight
- Wheelbase
- 1485 mm
- Overall length
- 2185 mm
- Overall width
- 820 mm
- Overall height
- 1265 mm
- Seat height
- 950 mm
- Dry weight
- 107.0 kg
- Wet weight
- 111.6 kg
- Fuel capacity
- 6.20 litres
- Ground clearance
- 335 mm
Chassis & suspension
- Frame
- Aluminum perimeter
- Front suspension
- 49mm inverted telescopic coil-spring fork with 16-way compression damping and 16-way rebound damping
- Rear suspension
- Uni-Trak® gas charged shock with piggyback reservoir with dual-range (4 turns stepless high speed/19-way low-speed) compression damping, 38-way rebound damping and adjustable preload
- Front wheel travel
- 305 mm
- Rear wheel travel
- 307 mm
- Rake (fork angle)
- 27.6°
- Trail
- 119 mm
Brakes & wheels
- Front brakes
- Single disc. Semi-floating petal discs
- Front brakes diameter
- 270 mm
- Rear brakes
- Single disc. Single-piston caliper.
- Front tyre
- 80/100-21
- Rear tyre
- 120/80-18
Other
- Color options
- Lime Green
Compiled from manufacturer documentation and user contributions, corrected on an ongoing basis. Spotted something wrong? Tell us.
What changed, year to year
Differences highlighted| Specification | 2021 | 2023 | 2024 | 2026 | 2027 |
|---|---|---|---|---|---|
| Capacity | 449 cc | 449 cc | 449 cc | 449 cc | 449 cc |
| Dry weight | 107 kg | 107 kg | 107 kg | 107 kg | — |
| Seat height | 950 mm | 950 mm | 950 mm | 950 mm | 955 mm |
| Fuel capacity | 6.2 L | 6.2 L | 6.2 L | 6.2 L | 7.5 L |
Illustrative - generated automatically by diffing the year records already on file, not a manufacturer-published changelog.
Rider Reviews
Common questions
What is the engine size of the Kawasaki KX450X?
The 2021 Kawasaki KX450X has a Capacity of 449.0 ccm (27.40 cubic inches).
What engine power does the Kawasaki KX450X have?
The 2021 Kawasaki KX450X has a Power of 56.0 HP (41.2 kW).
How many gears does the Kawasaki KX450X have?
The 2021 Kawasaki KX450X has a Gearbox of 5-speed.
How much does the Kawasaki KX450X weigh?
The 2021 Kawasaki KX450X has a Dry weight of 107.0 kg (235.9 pounds).
Shop this bike
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The 2021 Kawasaki KX450X is an impressive off-road motorcycle that delivers power, agility, and durability. With its potent 449cc engine, lightweight chassis, and advanced suspension system, this bike is designed to tackle the toughest trails and terrains with ease. The refined ergonomics and adjustable footpegs ensure a comfortable and customizable riding experience for riders of all sizes. Additionally, the KX450X features a high-performance braking system and a rugged frame, making it a reliable and capable off-road companion.
Overall, the 2021 Kawasaki KX450X is a top-tier off-road motorcycle that offers exceptional performance and versatility. Whether you're a weekend trail rider or a competitive racer, this bike has the power, handling, and durability to meet your off-road demands. With its advanced features and aggressive styling, the KX450X is a standout choice for anyone seeking an exhilarating and capable off-road experience.
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