Motorcycle specifications KawasakiKX 450 F 2015 Champion performance

the KX's mission statement can be summed up in a few words: to lead intermediate to expert riders to victory. And it hasn't changed since the KX was created forty years ago. With 32 AMA Supercross titles to their credit - a record for all manufacturers combined - KXs have long proved that they are the stuff of champions. In addition to their proven engine and chassis performance, a number of cutting-edge technologies and "firsts", and tweaks for 2015, make this new KX 450 F model formidable

the 449 cm3, liquid-cooled, 4-stroke single delivers its bite across the entire rev counter. The highly exploitable powerband and responsive acceleration deliver a torrent of torque that allows riders to push the throttle right from low revs. Thanks to parts and settings inspired by racing machines, such as the high-performance piston with internal bridge cap (first seen on a production model in the 2010 KX 450 F), performance is at its best right out of the box! Thanks to the redesigned piston crown and new ECU settings, the 2015 version features a "peppier" engine that revs up faster. What's more, the compression ratio has been increased from 12.5 to 12.8:1.

launch Control mode: how to do the holeshot

For a long time, KX cross-country bikes have been inspired by factory techniques to offer riders masterful performance without any special preparation. Launch Control mode is just such a feature, giving riders a head start right from the starting grid. At the touch of a button, the driver can activate a distinct engine map that multiplies the chances of getting off to a good start in slippery conditions: by delaying ignition timing, Launch Control mode allows the rear tire to regain grip in low traction situations, allowing the driver to concentrate on his trajectory.
- This mode is activated by pressing and holding the Launch Control button on the left-hand switchgear for at least two seconds (an indicator light next to the button flashes rapidly to confirm to the rider that the mode has been activated)
- Launch Control mode operates in 1st and 2nd gears (and in neutral). As soon as the driver shifts into 3rd gear, the system automatically deactivates and reverts to normal mapping.
- The technical features of this system are identical to those of the factory Kawasaki models racing in AMA Supercross.

easy engine tuning: direct injection settings (choice of 3 mappings)

Thanks to the new DFI direct injection couplers, adjusting engine settings to suit riding conditions has never been easier: just plug in, and off you go!
- Instead of a single engine map, the new ECU has three (four including Launch Control mode).
- The default settings for the three maps are: Standard (normal conditions), Hard (difficult conditions) and Soft (easy conditions). using the supplied DFI couplers, the rider can easily switch from one map to another, adapting the settings to riding conditions. Simply plug in one or other of the 4-pin couplers to activate the corresponding map (the plug's location, on the right of the steering column, allows easy access without disassembling any parts)
- The optional KX FI injection calibration kit can be used to reprogram all three mappings

battery-free injection system

Specially designed for cross-country machines, the injection power supply incorporates a small, lightweight ECU and operates without a battery, to avoid unnecessary overcharging. What's more, it eliminates the need to make engine adjustments according to track and weather conditions.

factory components and preparation for the chassis

The aluminum perimeter frame of the KX 450 F is a narrow, lightweight structure made up of forged, extruded and cast parts. The balancing and adjustments of the chassis have been designed for experienced riders. The position of the center of gravity and the main dimensions (swingarm axle, gearbox output pinion and rear wheel axle) have been chosen so that the rear tire propels the machine, rather than compressing the rear axle under acceleration. To add to the already recognized qualities of the KX 450 F: high-speed stability, maneuverability and simple ergonomic race settings, the 2015 model is now equipped with a new SFF-Air TAC fork for faster riding.

perfected suspension technology: SFF-Air TAC (triple air chamber)

The KX 450 F is equipped with Showa's new SFF (Separate Function Fork)-Air TAC (Triple Air Chamber). The factory-style fork is very light and very stiff, for a more stable ride. Designed for intermediate to expert riders, the new fork perfectly absorbs shocks at high speeds, facilitating faster riding. Many other benefits:
- high rigidity
- light weight
- low friction
- limited effects of heat thanks to the shock-absorbing element
- precise adjustment possible by simply changing the air pressure
- Easy adjustment

- New: Independent shock absorption and damping functions:
Left fork tube: shock-absorbing element
Right fork tube: air spring
This configuration ensures both smooth operation and firm damping - a combination difficult to achieve with conventional forks.

- New - The large 49mm-diameter inner tubes (the same dimensions as on our factory bikes) stiffen the fork, enhancing front-wheel grip.

- New - The left and right fork tubes together weigh just 7,950 g, making for an ultra-light structure (some 840 g lighter than a conventional fork).

- New - The right-hand tube of the SFF-Air TAC fork features three air-filled chambers that act like a spring, rather than coil springs (as on a conventional fork):
Inner chamber: main air spring
Outer chamber: secondary air spring
Balancing chamber: balancing air spring

- New - The inner chamber, with a standard pressure of 1,000 kPa (range 600 to 1,300 kPa), does most of the work, supporting at least 60% of the motorcycle's weight.

- New - The outer chamber, with a standard pressure of 50 kPa (range 0 to 130 kPa), supports the inner chamber, as does the outer cylinder air chamber of a conventional fork.

- New - The balancing chamber, with a standard pressure of 900 kPa (range 530 to 1,400 kPa), exerts a reactive force on the inner chamber for greater riding comfort. When the fork is fully extended, inner chamber pressure is minimal and balancing chamber pressure is maximal; when the fork is fully compressed, inner chamber pressure is maximal and balancing chamber pressure is minimal.

- New - In the absence of main springs, it's much simpler to change the characteristics of the SFF-Air TAC fork than it is to change the spring settings on a conventional fork. By simply adjusting the air pressure, the TAC's "setting" can be adjusted without the hassle of disassembly. This means that adjustments can be made on site to suit the rider and the track, with no additional parts and minimal tooling.

- New - The pneumatic pressure can be adjusted by means of a high-pressure pump (we recommend using a pump equipped with a pressure gauge and flexible hose).

- New - This TAC air pressure adjustment covers the adjustment range offered by optional springs on a conventional fork.

- New - In the compression phase, compressed air strongly opposes bottoming, helping to improve resistance to bottoming. conversely, in the rebound phase, it offers less resistance, which enhances roadholding and front-end grip.

- New - In a conventional fork, friction between the springs and inner tubes is particularly noticeable in the second half of the travel. eliminating the main springs alone reduces this friction by around 20%. The balancing chamber eliminates the need for a balancing spring, making a significant contribution to reducing friction. The low friction results in a much smoother ride over the entire length of the travel

- New - The use of a larger shock absorber piston (thanks to the elimination of fork springs) not only enhances the progressiveness of suspension work, but also allows for firmer damping. The shock absorber piston measures 30 mm in diameter (compared with 24 mm on a conventional fork).

- New - As with a conventional fork, compression and rebound damping can be adjusted.

- New - Balance chamber pressure can be set as initial preload.

- New - A high-strength titanium coating on the outer surface of the inner fork tubes protects against abrasive wear. This dark blue coating also makes the tubes less susceptible to scratches and wear. The surface remains smooth for longer, reducing friction (and grip) and improving ride quality.

- New - A self-lubricating alumite coating creates a hard, low-friction surface on the outer tubes. The hard coating protects against abrasive wear on the inside of the tubes, so surfaces remain smooth for longer, while the outside is protected against corrosion. The lubricating material in the coating improves travel (especially at the start of compression) and thus riding pleasure.

race-typical rear suspension

- The rear shock absorber offers two distinct compression damping settings: fast and slow.
- A self-lubricating alumite coating on the shock reservoir protects against abrasive wear and reduces friction for smoother operation.
- New - New valve settings improve damping. Harder settings improve handling and stability at high speeds, as well as performance when landing jumps.
- The new Uni-Trak rear suspension system features a tie-rod under the swingarm, which increases the amplitude of travel and in turn allows finer adjustment.
- Extensive riding tests have determined the ideal values for travel ratios and shock absorber settings for maximum rear-wheel drive.

refined, adjustable riding position

The KX450's ergonomically designed frame and minimalist cladding refine the machine's silhouette, making it particularly well-suited to track use. Complemented by adjustable handlebars and footrests, this natural riding position enhances rider comfort and speed.

other racing features on the chassis

- New - Petal disc brakes are just one of the many factory components fitted to the KX 450 F. The elegant new discs underline the bike's premium sporty styling.

- New - The oversized 270 mm front disc not only greatly increases front brake power, but also improves braking control.

- Factory-style Renthal handlebars (standard type) in aluminum are supplied as standard.

- New - The front and rear axles have been lightened by 31g and 32g respectively.

- New - Refined rear frame tube walls (t2.0 mm >> t1.8 mm) have been lightened by around 50g.

factory look

With its minimalist cladding, mudguard and racing plates, the KX 450 F is unquestionably the most radical machine in the paddock, and its factory-inspired graphics reflect its sharp performance. The green highlights on the 2015 model's suspension adjusters, oil filler cap and alternator housing inspection plugs add to the distinctive Kawasaki look...

News and media: Kawasaki