All-new engine. Race-bred chassis. Built to compete.
The 2027 Beta RX 250F 4-Stroke marks Beta's entry into the 250cc four-stroke motocross class. Designed and developed from the ground up in Italy, the RX 250F combines a new high-output 249.3cc engine with a dedicated chassis, KYB suspension and advanced electronic rider controls.
At the heart of the RX 250F is an all-new 249.3cc liquid-cooled single-cylinder four-stroke engine featuring DOHC finger-follower valvetrain technology and four titanium valves. The compact powerplant uses a 46mm tapered throttle body with dual fuel injectors, designed to improve air-fuel delivery and provide strong throttle response throughout the rev range.
Beta designed the RX 250F around the specific characteristics of a 250cc four-stroke motocross bike. Its chromoly steel double-cradle frame uses dedicated engine mounting points intended to increase torsional stiffness while maintaining vertical flexibility, helping balance cornering precision, traction and stability.
Key Specifications
Engine: 249.3cc liquid-cooled 4-stroke
Bore x Stroke: 78mm x 52.3mm
Compression Ratio: 14.4:1
Valvetrain: DOHC finger followers, 4 titanium valves
Fuel System: EFI, 46mm tapered throttle body, dual injectors
Starting: Electric start
Transmission: 5-speed
Clutch: Wet diaphragm-style
Oil System: Twin oil pumps with separate engine/transmission compartments
Front Suspension: 48mm KYB AOS closed-cartridge fork
Rear Suspension: KYB 50mm shock with linkage
Front Travel: 12.0"
Rear Travel: 11.8"
Front Brake: 260mm floating rotor
Rear Brake: 240mm rotor
Front Wheel: 21"
Rear Wheel: 19"
Tires: Dunlop Geomax MX34
Seat Height: 37.6"
Ground Clearance: 13.4"
Fuel Capacity: 1.85 gallons
Wheelbase: 58.0"
Dry Weight: 222.7 lbs
Race-bred power. Smarter electronics. Built for the motocross track.
The 2027 Beta RX 450F 4-Stroke is Beta's flagship four-stroke motocross machine, combining a powerful 449.3cc liquid-cooled single-cylinder engine with KYB suspension and a race-focused chassis. Developed for closed-course competition, the RX 450F is designed to deliver strong power while maintaining the predictable, controllable handling that Beta calls its RideAbility philosophy.
For 2027, Beta focused heavily on refining the RX 450F's engine power delivery and electronic controls. The bike now adds 5-level Launch Control and Quick Shift to its existing dual engine maps and Traction Control. All of these functions are managed through a redesigned integrated control panel, allowing riders to quickly adapt the bike to changing track and traction conditions.
Key Specifications
Engine: 449.3cc liquid-cooled 4-stroke single-cylinder
Bore x Stroke: 97mm x 60.8mm
Compression Ratio: 13.5:1
Valvetrain: 4-valve
Fuel System: EFI with 46mm tapered throttle body
Starting: Electric
Transmission: 5-speed
Clutch: Hydraulic diaphragm multi-plate
Front Suspension: 48mm KYB AOS
Rear Suspension: KYB shock with linkage
Front Travel: 12.0"
Rear Travel: 11.8"
Front Brake: 260mm floating rotor
Rear Brake: 240mm rotor
Front Wheel: 21"
Rear Wheel: 19"
Tires: Motocross competition tires
Seat Height: 37.2"
Ground Clearance: Approximately 13"
Fuel Capacity: 2.4 gallons
Dry Weight: Approximately 229 lbs
Lightweight. Aggressive. Built to attack the track.
The 2027 Beta RX 250 2-Stroke brings high-revving two-stroke performance to Beta's motocross lineup. Designed for riders who want a lightweight, responsive 250cc race bike, the RX 250 combines a 249.3cc liquid-cooled two-stroke engine with a race-focused chromoly steel chassis and KYB suspension.
For 2027, Beta gives the RX 250 a number of important updates, including new engine cases, a new cylinder, revised cylinder head and combustion chamber, updated exhaust components, stronger muffler construction and revised final gearing. The new 14/51 final gearing is designed to improve starts and allow the engine to pull smoothly through fast sections.
Key Specifications
Engine: 249.3cc liquid-cooled 2-stroke
Bore x Stroke: 66.4mm x 72mm
Compression Ratio: 14.6:1
Power Valve: Beta Progressive Valve (BPV)
Carburetor: Keihin PWK 38mm
Starting: Electric start
Transmission: 5-speed
Clutch: Wet diaphragm-style
Front Suspension: 48mm KYB AOS closed cartridge
Rear Suspension: KYB 50mm shock
Front Travel: 12.0"
Rear Travel: 11.8"
Front Brake: 260mm floating rotor
Rear Brake: 240mm rotor
Front Wheel: 21"
Rear Wheel: 19"
Tires: Dunlop Geomax MX34
Seat Height: 37.3"
Ground Clearance: 13.4"
Fuel Capacity: 1.85 gallons
Dry Weight: 220.5 lbs
Massive torque. Lightweight two-stroke character. Built to dominate the track.
The 2027 Beta RX 350 2-Stroke brings big-bore two-stroke performance to Beta's motocross lineup. Its 351.7cc liquid-cooled single-cylinder engine combines a 78mm bore with a 73.6mm stroke, delivering the strong torque and horsepower that make the 350 RX unique in the motocross world.
Beta designed the RX 350 around a linear and controllable power delivery, giving riders access to its substantial power without sacrificing the rideability expected from a modern Beta. The engine features a Beta Progressive Valve (BPV) power valve, counterbalancer, twin-plug cylinder head, Keihin PWK 38mm carburetor, electric start and a 5-speed transmission.
Key Specifications
Engine: 351.7cc liquid-cooled 2-stroke
Bore x Stroke: 78mm x 73.6mm
Compression Ratio: 12.45:1
Power Valve: Beta Progressive Valve (BPV)
Cylinder Head: Twin-plug
Carburetor: Keihin PWK 38mm
Lubrication: Premix
Starting: Electric start
Transmission: 5-speed
Clutch: Wet diaphragm-style
Front Suspension: 48mm KYB AOS closed cartridge
Rear Suspension: KYB 50mm shock
Front Travel: 12"
Rear Travel: 11.8"
Front Brake: 260mm floating rotor
Rear Brake: 240mm rotor
Front Wheel: 21"
Rear Wheel: 19"
Tires: Dunlop Geomax MX34
Seat Height: 37.2"
Ground Clearance: 13.4"
Fuel Capacity: 1.85 gallons
Dry Weight: 220.5 lbs