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The chassis, based on a race-proven perimeter frame, benefits from a new linkage system for the Uni-Trak rear suspension that both improves suspension action and allows a lighter frame construction. Newly designed bodywork features a slim design and new seat for improved rider mobility.

• The KX250F chassis, based on a race-proven perimeter frame, now has new D-section tubes for the upper frame rails (43 x 25 mm).

• The curved outer edges of the frame rails allow the bodywork to hug the frame more tightly, for a slimmer design and an improved riding position.

• Steep castor angle enhances cornering performance.

• The footpegs are located higher and closer together, allowing more bank angle when turning.

• Front Suspension - New Kayaba bladder fork features check valves on the bladders to control their internal pressure. The result is improved damping and better fork action throughout the stroke.

• Rear Suspension - The most important chassis change from the previous KX models is the new-link Uni-Trak rear suspension system. Unlike the previous system in which the link pivoted on the frame, in the new system the link pivots on the swingarm. In addition to the lighter frame construction possible due to the brunt of suspension loads being absorbed by the swingarm instead of the frame, a second benefit is that the shock absorber now moves in an outward arc as it compresses, rather than moving out and back in. This smoother, more stable action significantly improves traction at the rear wheel, particularly when accelerating.

• The swingarm is new, and features a new cast bracket just aft of the shock to suit the new link, new forged axle holders and light 8 mm chain adjuster bolts. The new swingarm also features tapered, hydroformed beams.

• The top clamp uses a lightweight aluminium steering stem nut and a thin 1 mm stainless steel washer. Aluminium steering stem is tapered for low weight.

•  Compact axle brackets for the front fork use a new clamping method.

• The suspension arm is new and is an aluminium forging.

• The swingarm’s single-piece actuating rod is forged. The new design is both simple and strong.

• Rear shock features a drain bolt to facilitate oil changes.

• The upper shock mount is positioned to facilitate access to the carb.

• Slim exterior design contributes to improved rider mobility and a better riding position.

• The reshaped seat is flatter and uses a new seat cover texture that resists slipping.

The braking system is as follows

• New front brake hose routed directly to the front brake caliper. Thin brake line made of a single layer of Kevlar contributes to brake feel and reduced weight.

• Dual-piston front brake caliper uses 27 mm pistons and is operated by a master cylinder with 11 mm piston.

• Lightweight rear brake caliper uses 25.4 mm diameter pistons. Compact caliper ensures adequate clearance for the muffler when the suspension is fully compressed.

• New brake pedal is forged for high strength and light weight.

Specifications - KX250-N1

• Engine - Liquid-cooled, 4-stroke Single

• Capacity - 249 cm3

• Bore x Stroke - 77.0 x 53.6 mm

• Compression Ratio - 12.1:1

• Valvetrain - DOHC, 4 valves

• Induction - Keihin FCR37

• Ignition - Digital AC-CDI

• Claimed power - 43hp (31.6kw) @ 11,000rpm

• Claimed torque - 28.7 N-m (2.93kgf-m) @ 8,500rpm

• Starting - Primary kick

• Lubrication - Forced lubrication, semi-dry sump

• Gearbox - 5-speed, return

• Clutch - Wet multi-disc, manual

• Frame - Perimeter, high-tensile steel (D-section tubes for upper frame rails)

• Front wheel travel - 300mm

• Rear wheel travel - 310mm

• Front tyre - 80/100-21 51M

• Rear Tyre - 100/90-19 57M

• Caster (Rake) - 26.5°

• Trail - 110mm

• Steering angle - 42° both left and right

• Front Suspension - 48mm upside-down cartridge telescopic forks, compression and rebound damping both 16-step adjustable

• Rear Suspension - New Uni-Trak single shock, compression and rebound damping both 16-step adjustable, preload fully adjustable

• Front Brake - Single semi-floating 250mm disc with dual-piston caliper

• Rear Brake - Single 240mm disc with single-piston caliper

• Length - 2,170mm

• Width - 840mm

• Height - 1,270mm

• Wheelbase - 1,475mm

• Ground clearance - 340mm

• Seat height - 950mm

• Dry Weight - 92.5kg

• Fuel capacity - 7.5 litres

• Available - September/October