Beta announce their 2026 RX (motocross) range of off-road motorcycles which includes a new 350cc two-stroke, alongside the 250 2T and 450 four-stroke, a “fun” bike boasting all the benefits of a smoker but the power of a four-banger.

A 78mm bore, 38mm Keihin carbed, electric start, 100kg, 351.7cc two-stroke? Is this a dream? If you’re not a fan of fuel injection, or the electric bike revolution going on, then the 2026 Beta RX model range must come as sweet music to your ears.

Consisting of three models – a 250 and 350 two-stroke and 450 four-stroke – the RX range from the Italian manufacturer is still relatively new to the world and in a strong development phase as they try to get on par with the opposition.

One thing Beta are certainly doing differently to any rival manufacturers is introducing a sweet and surprising model range which is as much aimed at keeping moto racers happy as it is trying to burst the MX2/MX1 classes and capacity bubble. It seems more like a range of bikes aimed at real world riders.

A 450 four-stroke, yep, they need that for MXGP. A 250 two-stroke, yep, because the world always needs a 250 2T. But a 350 2T? Hell yes, this is the bike you didn’t know you needed.

2T weight and maintenance advantages, 4T power

“Easy to ride yet high in performance”, Beta say in their press information about the new RX models. Bikes, they add, designed to get the best from any rider.

The RX 350 two-stroke is ambitious to say the least, but we already saw it make a debut at the EICMA motorcycle show last year when they rolled one out in flattrack guise for Casey Stoner to ride.

Beta say they set themselves a goal of combining the advantages of the 2T with a power delivery similar to a 4T: “full-bodied and linear at any speed, powerful and yet always manageable”.

Why a two-stroke engine? For its simplicity of use, assembly and maintenance, Beta say. Pre-mix is perfect for recreational or race use and an engine that “provides a vast amount of useable power yet remains low-cost to maintain”. 

They add the additional cubic centimetres compared to the outgoing 300 bring Beta’s typical Enduro racing characteristics only a bit more “full-bodied”.

Designed for non-professional riders who ride regularly

The new RX 300 was designed for non-professional riders who ride regularly and who want to have fun without too much fatigue, by exploiting the lightness and rideability of a lightweight and high-performing 2T model. 

This stands alongside the “all-new” RX 250 two-stroke, a more race focused bike it seems and a platform for racers but also expanding the possibility of using Beta motocross models in different classes.

The RX 450 4T meanwhile is the production version of the race bike that’s been running in the MXGP World Championship for five years now and in the American AMA Supercross series since 2024.

Beta say the 2026 RX 450 has been updated with a massive performance step, making the power delivery close to that of the factory bikes, while keeping the brand’s signature ease of control intact.

2026 Beta RX models in detail:

RX 450 4T

Engine: the 450cc engine development was focused on providing “a significant performance increase” compared to the previous model with a stronger torque curve that can be used under all conditions.

A new cylinder head with a higher performing piston, a new intake manifold and a different exhaust system are all responsible.

The cylinderhead overhaul – developed through CFD analysis and many flow bench calibrations – includes an improved intake duct to improve air circulation inside the engine. The new manifold, following the flow line, has a longer internal “horn” (shape) to improve the tuning of pressure waves, and increase their volume while sucking in air.

The ’26 piston has new coatings to reduce friction and improve its performance while a new design counter balancer was introduced to contain vibrations and reduce rider fatigue.

Exhaust system: the head-pipe has been redesigned to improve flow and increase power. This new 4T exhaust system also has a new silencer, redesigned with HGS to contain the DB output, in line with the new racing standards.

Map: maps were updated with the new motor configuration, with renewed start-up and limiter “strategies”, Beta say. 

RX 250 and 350 2T

Engine: both RX two-stroke models have completely new, purpose-built engines. The RX 350 was designed to produce the strong but linear power delivery and give riders the option to exploit the greater power available when needed. While the RX 250 is more focused on “explosive performance”, ready to compete in races under all conditions. 

Cylinderhead: The first noticeable difference when looking at the new engines is certainly the twin-spark plug head on the RX 350 2T, while the 250cc relies on a single 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 four-stroke bikes, while the 350cc boasts greater torque and a rounded delivery for ease of recreational use, at lower speeds while still provides enough overall horsepower for race use, Beta add.

Cylinder, piston and power valve: to further differentiate the two bikes, Beta engineers worked on new cylinders and pistons, designed specifically for each engine. The power valve was also calibrated accurately to manage the two deliveries with 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 models’ crankshaft.

Gearbox: the five-speed gearboxes are shared between both models with the only difference being the final ratios of the sprockets, 13/50 for the 250 and a 13/47 for its big sister.

Exhaust: New exhaust systems were designed for the features of both engines, and differ in the internal silencer diameter (bigger on the 350). 

New components shared by all RX models:

• Details common on the entire range include fresh graphics and stronger radiators to help prevent deformation that might affect their operation, even during heavy-duty use.
• Frame: geometry remains unchanged except for a cast-in brace to strengthen the frame around the steering neck area. This increases the reliability and stiffness of the frame’s area most subject to stress.
• Aluminium rear sub-frame and dedicated airfilter box: aluminium gives the right level of stiffness to the structure. Access to the filter is on the left side of the bike, and is intuitive and tool free to replace. The push button seat also removes without tools. 
• Kayaba suspensions: fork (48mm) and single shock (50mm) are calibrated for the new range, focusing on their rideability and stability. The settings are enough to make any rider confident, from amateurs to professionals, Beta say. 
• Nissin braking system: with floating callipers and 260mm Galfer discs at the front and 240mm at the rear.
• Chain: non o-ring is lighter and smoother.
• Lithium battery
• Handlebar silent block: Xtrig Flexfit bar mounts as standard provide a comfortable grip on the handlebar for enhanced control and reduced vibration. 
• Engine maps: all the RX models are equipped with two specific engine maps (wet and dry), while the four-stroke 450 also has four levels of Traction Control (on/off/active with hard map/active with soft map). The button to select the map and TC is located on the handlebar pad.
• All RX models will be supplied with personalised kickstand plus the RX 450 has four different throttle cams as standard to customise the throttle response.
• Enduro21 adds in here the cleat plastic fuel tanks so you can see how much gas in the bank.

Availability: June in Europe, September in North America, October in Australia (sorry Oz!).

Prices not known

Technical Specifications:

More information: www.betamotor.com