BetaMotor has announced a major expansion of its motocross program, with the launch of the 2026 Beta RX 350 2T and changes to the RX range, marking a bold new chapter in the brand’s off-road journey. With the introduction of two all-new 2-stroke models and significant updates to the RX 450 4-stroke, Beta continues to solidify its commitment to motocross innovation, performance, and fun.

Following its global debut at EICMA, the RX 350 2T was unveiled at the Champions Charity Race and piloted by Australian MotoGP legend, Casey Stoner, which caught the attention of riders across the globe. Alongside the RX 350 2T, the new RX 250 2T was also unveiled — two new models designed to shake up the 2-stroke market. Those models now become a production reality and sit alongside the MY26 RX 450 4T, which sees major updates. The result is a motocross range that offers performance, reliability, and the signature Beta RideAbility that empowers riders of all levels.

At the core of Beta’s design philosophy is RideAbility — creating bikes that are not only race-capable, but also accessible and enjoyable for riders of all skill levels. With this new RX lineup, Beta blends high-performance engineering with ride-friendly characteristics, ensuring riders get the most out of every ride.

The MY26 RX range is led by the new RX 350 2T, replacing the MY25 RX 300 2T. The MY26 RX 350 2T is a never-before-seen configuration in motocross and is a true innovation in the 2-stroke category. Developed to combine the agility and simplicity of a 2-stroke with the full-bodied, linear power delivery of a 4-stroke, the RX 350 is ideal for riders seeking high performance paired with ease of use. Featuring a dual-spark head for smoother combustion, a purpose-built power valve system, and optimised crankshaft and piston configurations, the RX 350 delivers robust power at any speed while remaining manageable and fun to ride.

Another new model for MY26 is the RX 250 2T, adding a lightweight, high-revving option for riders. With a completely new engine architecture, it offers explosive performance, nimble handling, and the ability to challenge in competitive race environments.

Head: The first noticeable difference when looking at the new engines is the dual-spark-plug head on the RX 350 2T, while the 250cc relies on a classic single spark plug configuration. 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 4T bikes, while the 350cc delivers greater torque and a rounded delivery, enhancing its ease of recreational use at lower speeds while still providing plenty of overall horsepower for race use.

Cylinder, piston and power valve: To further differentiate the two bikes (apart from the obvious engine capacity), Betamotor engineers developed new cylinders and pistons, designed specifically for each engine. The power valve was calibrated differently between the models 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, have been matched with each model’s crankshaft.

Gearbox: Gearboxes are 5-speed and 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 and designed to enhance the features of both engines, the exhausts differ in the internal silencer diameter, which is bigger on the 350cc.

The RX 450 4T is back for MY26 with a host of engine refinements that bring its performance closer than ever to the factory bikes competing in MXGP and AMA Supercross. The development of the 450cc engine focused on delivering a significant performance increase over the previous model, with a stronger, more usable torque curve across all riding conditions. This achievement was made 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 increases volume while intaking air. The piston includes new coatings to reduce friction and improve its performance. A newly designed counterbalancer was introduced to contain vibrations and reduce rider fatigue.

The RX 450 4T also features a new HGS exhaust system, co-developed with HGS to create greater flow and increased power. Engine maps have been reworked for the new motor, with new start-up and limiter strategies. The RX 450 has four throttle pulleys so riders can tailor the throttle response.

New components shared by both 2T & 4T models:

Graphics: A modern race look, simple yet bold, the final touch to the Italian RX range.

Radiators: Structurally strengthened to prevent deformation, even during heavy use.

Shared Features Across the RX Range:

All 2026 RX models share the following upgraded features, ensuring consistency in quality and performance:

  • The frame now features a cast-in brace to further strengthen the frame around the steering neck area, increasing stiffness.
  • Aluminium subframe offering light, yet stiff structure with the rigidity to overcome the demands of motocross. Access to the air filter remains unchanged and is tool-free.
  • Kayaba 48mm forks and 50mm shock, calibrated specifically for MX applications.
  • Nissin brakes with Galfer discs (260mm front / 240mm rear) for powerful, modular braking.
  • Xtrig Flexfit handlebar mounts for enhanced comfort and vibration dampening.
  • Electric start with lithium battery, lighter and a must for quick starts.
  • Non o-ring chain, lighter and smoother.
  • Two engine maps (wet/dry) on all models, with the RX 450 4T also offering four levels of Traction Control.