Beta Motorcycles 250RX

250-350 RX 2 Stroke

Engine: Both engine capacities received a completely new, purpose-built engine. The 350 RX was designed to obtain the greatest linear power delivery and give riders the option to exploit the great power available when needed, while the 250 RX can count on explosive performance, ready to compete in races under all conditions.

» Head: The first noticeable difference when looking at the new engines is certainly the dual-spark-plug head on the RX 350 2Str, while the 250cc still relies on a classic single spark plug. This differentiates the two motorcycles’ character even further, with the 250cc providing riders with a high-revving engine that competes with the likes of 250 4Str bikes, while the 350cc manages to keep a greater torque and rounded delivery, enhancing its ease of recreational use, at lower speeds, while still providing enough overall horsepower for race use.

» Cylinder, piston, and power valve: to further differentiate the two bikes, apart from the obvious engine capacity, Betamotor engineers worked on new cylinders and pistons, designed specifically for each engine. The power valve, too, was calibrated accurately to manage the two deliveries by adopting different springs.

» Crankshaft: the two motorcycles have a different stroke, with the 250cc reaching 72mm and the 350cc reaching 73.6mm.

» Crankcase: new engine crankcases, with different internals between the two capacities, matched with each model’s crankshaft.

» Gear box: gear boxes are shared between both models, with the only difference being the final ratios of the sprockets, 13/50 for the 250 and 13/47 for its big sister.

Exhaust: also new for both models. Exhaust systems were designed to enhance the features of both engines, and differ in the internal silencer diameter, which is bigger on the 350.

FEATURES

Kayaba (KYB) Suspension
Fork (48mm) and single shock (50mm) are specifically calibrated on the new range models, focusing on their rideability and stability when the pace rises. The resulting setting is enough to make any rider confident, from amateurs to professionals.

Suspension
Closed cartridge 48mm KYB front fork and the rear shock have been updated with new valving for better overall performance. 50mm shock body reduces the oil temperatures under extreme use during long motos.

Sub-Frame & Filter Box
Aluminum gives the right level of stiffness to the structure. Light, yet has the rigidity to overcome the demands of motocross. Access to the filter remains on the left side of the bike, and is extremely easy and intuitive, as well as being tool free. The push button seat also removes without tools.

New Aluminum Sub Frame
Similar to the 450 RX the sub frame on the 250-350 RX is fabricated from aluminum for more strength.

Frame
Geometry remains unchanged, yet the frame now incorporates a cast-in brace to further strengthen the frame around the steering neck area. This increases the reliability and stiffness of the frame's area most subject to stress.

Engine
The 350 RX was designed to obtain the greatest linear power delivery and give riders the option to exploit the great power available when needed, while the 250 RX can count on explosive performance, ready to compete in races under all conditions.

Bodywork
Get the frame now incorporates a cast-in brace to further strengthen the frame around the steering neck area. This increase the reliability and stiffness of the frame's area most subject to stress.