Beta Motorcycles 450 RX

450 RX: Proven through races all over the world, including the USA Supercross series and MXGP. The 450 RX provides a ride like no other, quick turning yet stable; powerful yet easy to ride, are just a few things the press is saying about the 4-stroke model. An engine with enough power for a top-level pro rider while providing the right amount of power to the amateur as well. For 2026, the 450 RX receives a new cylinder head with improved flow that provides even more power. This, along with a matched intake manifold and a new exhaust, means the 450 will still bark with power but do it in a quieter way. A redesigned counterbalance shaft to reduce vibration and new mapping to go with the new cylinder head and exhaust.

Engine: The 450cc engine development was focused on providing riders a significant performance increase compared to the previous model, offering a stronger torque curve that can be used under all conditions. This achievement was possible due to a new cylinder head with a performance-enhancing piston, a new intake manifold, and a different exhaust system. The head’s overhaul - developed through CFD analysis and many flow bench calibrations - includes an improved intake duct to enhance air circulation inside the engine. The new manifold, following the flow line, has a longer internal horn to improve the tuning of pressure waves, and thus increase their fill while intaking air. The piston includes new coatings to reduce friction and improve its performance. A newly designed counter balancer was introduced to contain vibrations and reduce rider fatigue.

Exhaust system: the head-pipe has been redesigned to create a greater flow and to provide increased power. This new 4-stroke exhaust system is completed by a silencer, redesigned with HGS to contain the DB output, in line with the new racing standards.

Maps: Updated to perform better with the new motor configuration, with renewed start-up and limiter strategies.

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.