2025 Beta RX Models

Beta USA entered the motocross world in 2021 with the introduction of their 300 RX, a two-stroke model that provided a solid platform in design, handling and looks. Along with the beauty of the bike, the “factory sound” of the 293cc motor was like no other. Riders quickly discovered what Beta likes to call “rideability.” In 2024, Beta launched another RX model that would show off the talents of the engineering team based in Florence, Italy. The 450 RX four-stroke had been tested in the prestigious MXGP class for more than three years as a factory prototype model. The production version of this prototype was very well received by riders as well as the media.

For the 2025 season, Beta released the details of both the 300 and 450 RX with updates to enhance both models. Updates to the 300 include changes to the engine, chassis and suspension. A new frame highlights the model, one that mimics that of its older 450 brother.

The 450 RX model also received updates, bringing it closer to perfection than ever. Updates to sharpen the model’s weapons, which are ready to do battle on motocross tracks throughout the U.S., include an even stronger rear aluminum subframe, suspension upgrades, as well as a more powerful lithium battery.

What does “rideability” mean for Beta? It means designing and manufacturing motorcycles with a balance and feel that makes them easier to ride. A motorcycle able to get all the best from any rider, thanks to an engine-frame combination which is fun to ride, yet does not tire the rider with a more forgiving engine — an engine that is focused on putting power to the ground and creating a center of gravity balance that is not found in many other brands. This feeling can only be felt by riding the bike, a feeling that Beta owners already know.

Here is a list of the new features and updates.

300 RX 2-Stroke

Frame: Similar to the 450, specifically dedicated for motocross use, chro-moly with a larger backbone to increase stiffness while enhancing the turning. The new frame also has an updated mounting for the new rear brake master cylinder.
Rear brake master cylinder: New design, similar to the 450, large capacity for reduced fluid temperatures and better modulation and feel.
Rear sub-frame and filter box: In line with the use of the new frame, the rear subframe is fabricated from aluminum similar to the 450. This new subframe, along with the plastic tray system, allows for components under the seat, such as the battery and starter solenoid, to be more compact, reducing the overall bulk. The tool-less push button seat removal system is also incorporated into the new subframe.
Engine: Updated cylinder porting and new matched cylinder head along with a new ignition timing curve has increased the bike’s overall power. The engine pulls harder and longer with this new design. Combined with an all-new five-speed gearbox specifically for motocross and finished off with a stiffer spring for the diaphragm clutch pack, all provide for a complete package.
Footpegs: The 2025 model receives new, less bulky footpegs, with an enhanced grip performance provided to the rider’s boot to keep the bike under control at all times.
Exhaust: An updated expansion chamber attached to a shorter silencer specific for Moto
Radiators: New design that allows for a greater turning radius
Suspension: Closed cartridge 48-millimeter KYB front fork and the rear shock have been updated with new valving for better overall performance. The 300 receives a larger, 50-millimeter shock body to reduce the oil temperatures under extreme use during long motos.
Handlebar mounts: Isoelastic handlebar mounts are used to reduce vibration. These bar mounts also raise the handlebar height 5 millimeters.
Bodywork: Along with the aluminum subframe, the rear plastic is now a three-piece design. A new, smaller fuel tank (1.8 gallons) has been installed to reduce the overall weight and center of gravity. The MAP switch has been moved to the handlebar pad for ease-of-use.
New graphics and colors: More “Italian” red showing off the heritage of the Beta brand tied together with new graphics for 2025 bring a fresh new look to the RX.

450 RX 4-Stroke

Rear sub-frame and filter box: While the rear sub-frame’s geometry and the filter box remain the same, the structure has been reinforced in a series of points that stiffen and strengthen it, maintaining lightness and ability to absorb stresses. Access to the filter remains on the left side of the bike, is extremely easy and requires no tools to access.
Suspension: Closed-cartridge 48-millimeter KYB front fork and the rear shock have been updated with new valving for better overall performance.
Battery: A stronger lithium battery ensures quick starts while remaining very light in weight.
Final ratio: The rear sprocket has been replaced with a 51-tooth for a quicker “spin-up” of the power delivery.
Handlebar mounts: Isoelastic handlebar mounts are used to reduce vibration; these bar mounts also raise the handlebar height 5 millimeters.
Rear axle: The rear axle diameter has been increased to 22 millimeters to reduce flex and provide better durability.
Footpegs: The 2025 model receives new, less bulky footpegs, with an enhanced grip performance provided to the rider’s boot to keep the bike under control at all times.
New graphics and colors: More “Italian” red showing off the heritage of the Beta brand, tied together with new graphics for 2025, bring a fresh new look to the RX.
Updated engine mapping: The mapping has been updated with the latest settings that have been tested by the Beta race team. This, along with traction control, completes the electronic package of the RX model.
Throttle pulleys: Each 450 RX arrives with three extra throttle pulleys, all with a different ratio to allow riders to install the ratio to their liking.