Beta expands the RX motocross lineup for 2026 with the addition of two all-new two-stroke models, joining the proven 450 RX at the top of the range. The new 250 RX and 350 RX bring fresh performance options to the motocross segment, built on Beta’s racing experience at the highest level. After four seasons competing in MXGP and two years in AMA Supercross, the 450 RX has proven Beta’s competitiveness on the world stage—setting the foundation for this expanded RX family.

For 2026, Beta engineers in Italy took a bold step forward. The lineup now includes a true 250cc motocross machine designed for class-legal racing, and an all-new 350 RX aimed at riders looking for strong torque, usable power, and a unique big-bore two-stroke experience. As with every Beta motocross model, development centered on RideAbility—delivering performance that’s easier to control and more confidence-inspiring on the track.

350 RX – New for 2026

Replacing the previous 300, the 350 RX is completely new from the ground up. It features new engine cases, revised bore and stroke, and a twin-spark cylinder head designed to unlock the distinctive power of a big-bore two-stroke. A longer crankshaft and optimized final gearing help produce strong low-end torque and impressive top-end power, allowing the 350 RX to perform across a wide range of track conditions. The result is a motocross bike that stands apart from traditional class boundaries.

250 & 350 RX Two-Stroke Engine Platform

Both RX models are powered by all-new, purpose-built engines, each tuned to deliver a distinct riding character:

• Power delivery:
  The 350 RX focuses on smooth, linear output with ample torque on demand, while the 250 RX emphasizes quick-revving, aggressive performance suited for competitive racing.

• Cylinder head design:
  The 350 RX uses a dual-spark-plug head to enhance combustion efficiency and broaden the powerband. The 250 RX retains a single-spark configuration, supporting its high-rpm nature and race-focused character.

• Cylinder, piston & power valve:
  Each model receives its own dedicated cylinder and piston design, with the BPV power valve system calibrated using different springs to match each engine’s delivery.

• Crankshaft:
  Stroke length differs between models, with the 250 RX at 72mm and the 350 RX at 73.6mm, further separating their performance characteristics.

With two distinct personalities built on the same high-performance platform, the 2026 RX two-stroke lineup gives riders more choice than ever—whether the goal is race-ready aggression or big-bore torque with unmatched RideAbility.