2015 HONDA CRF250R Motocross Bike Chassis

The SFF-AIR-TAC front suspension has been developed for the CRF250R by Showa to unlock the frame’s extra performance potential and shaves over 1kg in weight compared to the 14YM. The fully adjustable right fork leg controls both compression and rebound damping force while the left fork leg compresses air using a damper-less structure. This distribution achieves a controlled right/left balance, enhancing reaction over bumps and stability while hard on the front brake.

 Three chambers are employed by the left fork leg to manage effective ‘spring’ rate. The Balance chamber operates from the off and at low speed; the Inner chamber is responsible for the mid-range stroke and the Outer Cylinder chamber is used as the forks near their bump stops.

Static sag and preload is changed by adjusting air pressure in the Inner and Balance chambers via a Schrader valve on the fork cap, and changing the oil volume in the Outer chamber.

 

There are no changes to the CRF250R’s sixth generation aluminium-twin beam frame, originally revealed on the 2013 CRF450R. The steering geometry of 27.38° with 116.7mm trail and wheelbase of 1,489mm works directly with the new Showa fork’s performance and gives a superb connection to the front tyre with increased feel for available side-grip on the limit. In combination with the low centre of gravity, this means side-to-side transitions ­– in the air or on the ground – require reduced rider input. All-up kerb weight is down to 105.4kg.

A CRF250R-exclusive lower cradle houses the engine. Careful packaging of equipment around the frame contributes to mass centralization; the electrical components (ECU, condenser, regulator and wiring harness) save weight and are centrally located below the throttle body. Efficient, lightweight radiators – specific to the CRF250R – mount low.

 The compact Showa shock also mounts low within the frame spars and uses a new spring material for 2015; it’s stronger and lighter by 220g with no change in spring rate. The aluminum swingarm features deep beam height in the front and centre sections, minimising rut deflection and improving rear tyre traction on corner exit.

Honda’s Pro-Link rear suspension linkage operates CRF250R-specific ratios and allows 31.7cm of travel. Fully adjustable, the rear shock features 17-position rebound adjustment; compression damping is separated into 13-position (low-speed) and 3.5 turns (high speed).

The 2015 CRF250R’s bodywork maintains Honda’s man maximum/machine minimum ethos that’s built around a rider’s needs, first and foremost. Efficient riding ergonomics are at the heart of the CRF250R shape. The radiator shrouds, side covers, lightweight seat and fuel tank offer a slim, smooth and continuous transition allowing the rider huge freedom and flexibility of movement.

 

In common with the CRF450R, new Black CRF decals and detailing mirror the factory racer’s look. Another detail change is the use of black radiator grilles in a hard-to-clean area. A new simplified fuel hose design helps with cleaning and maintenance; fuel capacity is 6.3 litres.

 

A larger 260mm wave-pattern front disc improves heat dissipation, power and feel from the two-piston brake caliper working it; a matching 240mm wave-pattern disc and single-piston caliper is at the rear. The new fork protectors and two-piece disc cover are finished in White, while the front and rear brakes guides are now Black.

 

Lightweight aluminium rims reduce unsprung weight. Both now wear top-specification Dunlop MX52F/MX52 80/100-21 front and 100/90-19 rear tyres which offer superb grip over a variety of conditions, with block-within-a-block knobs for more progressive side-grip and cornering, superior bump absorption from the sidewalls and recessed carcass design plus increased durability.