A high-performance, race-ready machine, Honda's CRF250RX is developed to compete in closed-course off-road races such as WORCS, NGPC and GNCC. Although based on the motorcross-focused CRF250R, this model has several features specifically engineered for trail use, and it performs exceptionally in everything from tight singletrack to the open desert. Trusted by teams like SLR Honda, Phoenix Racing Honda and JCR Honda, the CRF250RX is a potent podium contender from coast to coast.
HISTORY
Introduced for model-year 2019, the CRF250RX was based on the CRF250R motocrosser but developed for closed-course off-road racing. The model was overhauled for 2022, with changes aimed at reducing weight, increasing low-end power and improving durability. Another upgrade came in 2025, as the CRF250RX received the same chassis, suspension and engine updates as its motocross counterpart, achieving improved stability, comfort and power delivery.
OFF-ROAD-SPECIFIC FEATURES
Compared to the CRF250R motocrosser, the CRF250RX has the following differences:
- A resin 2.1-gallon fuel tank (instead of the R model's 1.7-gallon titanium cell) provides enough range to compete in closed-course off-road competition.
- Front and rear suspension have dedicated settings developed specifically for the closed-course off-road application, for good compliance over technical terrain like rocks and roots.
- The CRF250RX's ECU features a different fuel-injection map, with settings that deliver a smooth spread of power, maximizing traction in slippery, off-road conditions.
- Whereas the CRF250R has a 19-inch rear wheel, the CRF250RX has an 18-inch rear wheel, for a taller tire sidewall that better absorbs obstacles typically encountered off-road. In addition, front and rear tires are Dunlop Geomax AT81, which offer all-around performance, plus high levels of ruggedness for off-road racing and riding.
- The CRF250RX comes standard with plastic hand guards, to help fend off trailside bushes and brush.
- The model also has an aluminum side stand, which facilitates parking away from the pits but tucks out of the way when not in use.
STYLING / DESIGN
The standard CRF250R is known for its excellent ergonomics; the CRF250RX retains those, but adds features designed specifically for closed-course off-road racing. The radiator shrouds and side plates promote freedom of movement thanks to a smooth, flat surface, and although the bike is notable for its slim profile, the side-plate profile is wide enough to provide good contact for gripping the bike. Cooling the CRF250RX's engine is crucial to maintaining performance and overall durability. Computational fluid dynamics were used to design the air-outlet vents in the shrouds, and the radiator grilles are optimized in terms of both the number of fins and the fin angle. Each radiator shroud is produced in a single piece.
The seat base has rearward-facing tongues and front-located mounting tabs, an arrangement that eases installation, and acceleration forces keep the seat securely in place. Maintenance is simple, with only eight fasteners used to secure the main bodywork components, including the radiator shrouds, side plates and seat, all with 8mm bolt heads.
The Renthal® Fatbar® handlebar is held by a clamp that can be turned 180º; because the clamp itself has two mounting locations, there are four possible mounting positions for the handlebar, through a range of 26mm. The 2.1-gallon fuel tank is made of resin.
ENGINE / DRIVETRAIN
The 249cc liquid-cooled, single-cylinder, double-overhead camshaft, four-valve engine design achieves excellent performance and durability.
Intake
The airbox has a direct pathway for airflow, resulting in precise throttle control and excellent top-end power. The fuel injector's angle is 60 degrees, enabling the spray to reach all the way to the back of the butterfly, and the throttle bore is 44mm. Together, these features cool the intake charge, maximizing air-intake efficiency and torque at low revs. The air filter is held in place via a spring-loaded clip for easy serviceability.
Head
The bore and stroke are 79.0mm and 50.9mm, respectively, and the compression ratio is 13.9:1. The cylinder head features four titanium valves (33mm intake and 26mm exhaust), with the former using dual springs (one inside the other) to ensure precise movement at higher revs. The intake camshaft sprocket is press-fit, which enhances valve-timing accuracy while minimizing weight.
The camshaft holder has a rigid design that maintains camshaft-journal roundness, contributing to timing accuracy and minimizing friction at high rpm. Durability at high engine speeds is maximized by a high flow of lubrication to the oil-supply journal and the cylinder head. The water-pump gear is thick to maximize strength.
Exhaust
The exhaust system features a smooth, straight path for airflow, maximizing performance and acceleration in the middle and top rpm ranges. The system utilizes a single, straight exhaust port for good torque and low-rpm drivability. The single exhaust header is routed close to the engine on the right side, for a narrow cross-section and good rider mobility, and the single muffler has internal baffling that is optimized for torque delivery.
Clutch
The clutch pack has nine discs to maximize disc friction material and minimize the load on the individual discs. The clutch basket is rigid for durability, a friction spring reduces spring load, and lubrication is optimized to reduce wear. The primary ratio is 3.047.
Transmission
When designing the five-speed gearbox, engineers made efforts to enhance feel when making up- and downshifts between second and third gears—a very common operation on a 250 closed-course off-road bike; only one shift fork is operated to execute this gear-change. The countershaft has good rigidity, and the shift drum is light thanks to a large through hole and use of only two lead grooves.
Electronics
The CRF250RX has dedicated ignition and injection mapping, for optimized power delivery in closed-course off-road conditions. To fully realize the engine's performance potential, the ECU mapping supplies the optimum air/fuel mixture and ignition timing at all throttle positions and engine speeds. HRC-inspired launch control facilitates holeshots.
A gear-position sensor allows the use of three specific ignition maps for first and second gears, third and fourth gears, and fifth gear. There are options for Standard, Smooth and Aggressive ignition maps, selectable via a handlebar-mounted switch, enabling simple tuning depending on rider preference or course conditions.
- Mode 1: Standard
- Mode 2: Smooth
- Mode 3: Aggressive
In addition, Honda Selectable Torque Control offers three levels of intervention. HSTC monitors rpm spikes and responds by temporarily reducing torque; this is accomplished by retarding ignition timing and controlling PGM-FI, to aid rear traction. The three different modes differ in drive-management level, for differing riding conditions or rider preferences:
- Mode 1: The system intervenes the least, and waits the longest to do so—useful for reducing wheel-spin and maintaining control in tight corners.
- Mode 2: A midpoint between modes 1 and 3 in terms of how quickly and assertively the system intervenes.
- Mode 3: The system intervenes most quickly and assertively, which helps in conditions that are slippery or muddy.
The HSTC system can also be switched off completely.
HRC Launch Control provides the best option for a strong start and also has three modes to choose from:
- Level 1: 9,500 rpm, for high-traction conditions and/or advanced riders
- Level 2: 8,500 rpm, for high-traction conditions and/or average riders
- Level 3: 8,250 rpm, for slippery conditions and/or novice riders
CHASSIS / SUSPENSION
The standard CRF250R is known for its precise handling and overall rideability; those characteristics, which are also welcome in the gnarly conditions encountered in closed-course off-road competition, carry over to the CRF250RX.
Frame / Subframe
The mainframe contributes to a comfortable and confidence-inspiring ride. Optimized torsional rigidity contributes to overall stability, while an ideal torsional/lateral rigidity ratio allows for precise cornering. Vertical torsional rigidity is designed to enhance stability in rough track conditions.
Perhaps counterintuitively, a relatively high overall frame rigidity helps give the model a compliant, composed ride character. As with the standard CRF250R, the subframe mounting point is positioned at a rigid location on the mainframe, minimizing energy transmission from the rear of the motorcycle to the front, contributing to excellent stability and comfort.
Suspension
The 49mm inverted Showa coil-spring fork features kit-fork-inspired Bending Control Valves, and provides a consistent feel throughout the stroke, from initial movement to full compression, minimizing any harsh sensations. The outer fork tubes were developed in tandem with the steering stem and front axle to optimize rigidity for excellent bump-impact absorption and front-end feel, resulting in a comfortable, controlled ride.
The rear Pro-Link system has excellent bottoming resistance while preserving comfort over small bumps. The shock spring, reservoir, shaft and oil seal are designed to ensure a smooth, consistent feel throughout the stroke, complementing the frame and fork rigidity for an overall balanced performance. The shock absorber is easy to remove for service and adjustment, only requiring the removal of the side panels, muffler and ECU.
Wheels
The black D.I.D rims (21-inch front, 18-inch rear) deliver durable performance and good looks. The CRF250RX comes with Dunlop Geomax AT81 tires, which offer excellent all-around performance plus high levels of ruggedness for off-road racing.
Brakes
The front-brake caliper was developed based on feedback from Honda HRC Progressive riders, and it features two pistons (sized 30mm and 27mm), allowing for a smooth, linear feel that's consistent throughout the race. The caliper also features machined accents. The rear brake has a single piston. The brake rotors (sized 260mm front, 240mm rear) have a petal design to disperse heat.
