2025 BETA RX Range

Rx 300 450 My25 4
2025 BETA RX 300 & 450

The RX 450 was the first 4-stroke motocross bike built by the Italian, Rignano sull’Arno-based manufacturer and was the first chance for riders to experience a bike directly derived from the race prototype, which has now been racing for four years in the MXGP World Championship. While the RX 300 2T has been previously available as an enduro-derived bike for the motocross segment, the success of this project, and the ever-growing experience and insights gained on the RX 450 through the MXGP World Championship have led the Tuscan brand to open the throttle on the RX 300 and configure it as a fully-fledged motocross bike. For 2025, the RX 300 has undergone a series of important improvements to the engine, suspension and frame, which breaks away from the enduro world. Like the RX 450, it’s become a purpose-built bike, dedicated to motocross. The RX 450 also received exciting new updates that sharpened the model’s ability to perform on the track.

Rx 450 4t My25 18
2025 BETA RX 450

Within the vast range of changes across the board for the MY2025 RX range, the project’s goal remained the same: equip the bikes with a frame, engine and components of the highest level, and bring a new frontier of RideAbility to the MX world. What does RideAbility mean for Beta? It means designing and building bikes with RideAbility being the core value. Each Betamotor-branded motorbike is designed by the Florentine manufacturer to provide any rider with a motorcycle that is simultaneously easy to ride and offers high performance. A product that can extract the best from any rider, thanks to an engine-frame combination that can offer a fun ride without a reason to fear the world championship-level performance of the engine. For MY2025, the RX 300 and RX 450 achieve this goal, each in their way.

2025 BETA RX 450
2025 BETA RX 450 4-stroke

The MY2025 RX 450 sees the following changes:

Rear subframe and air filter housing: While the rear subframe geometry and air filter housing remain unchanged, the structure has been suitably reinforced in a series of stiffened and strengthened points, maintaining lightness and its ability to absorb impacts. Access to the filter remains on the left side of the bike, is extremely easy and intuitive to use, and is tool-free.

Suspension: the KYB fork and single shock package receive a new calibration that enhances the bike’s character, both in terms of handling and its stability when increasing the pace. The result is an improvement in manoeuvrability, stability, and confidence in every rider, regardless of their level.

Battery: The RX 450 has a new lithium battery with a higher amperage that delivers instant starting power.

Final ratio: To find an ideal compromise between speed and acceleration, the rear now features a 51-tooth sprocket, one up from the previous model year. This improves the response coming out of corners and allows the engine to build RPM quicker.

Graphics: While the plastics and new tail section remain unchanged, new, sleeker, and more aggressive graphics have been introduced, further highlighting this model’s racing pedigree.

Rx 300 2t My25 Sml
2025 BETA RX 300 2-stroke

The MY2025 RX 300 2T see the following changes: 

Frame: the RX 300 sees a new frame, specifically dedicated to motocross that receives a wider main spar (10mm), and redesigned and reinforced sections compared to the enduro models, built to withstand the stresses of repeated jump landings and lateral twists seen in high-speed bends. This translates to a precise and stable bike when entering and leaving corners quickly. The engine mounts and position differ from the enduro models and provide excellent balance on the track.

Rear sub-frame and air filter housing: The new RX 300 receives an aluminium sub-frame and air filter housing, in line with the use of the new motocross frame. 

2025 BETA RX 300

Fork: The Kayaba (KYB) 48mm forks have greater travel than the enduro models and receive new calibration that creates the perfect set-up. Together with the new single Kayaba shock, they deliver a stable, fast, and precise bike. 

Single shock: the single 50mm Kayaba shock is a new addition to this model and delivers greater support in jump landing, thanks to the greater hydraulic braking within the shock, guaranteeing constant performance under heavy use.

Braking system: Featuring Nissin floating callipers, a 260mm disc at the front, and 240mm at the rear. The front sees a new calliper as used on the RX 450, which is smaller, lighter and performs better than the previous unit, offering great braking performance when letting off the throttle. At the rear, the new master cylinder, as seen on the Enduro RR Racing models, delivers greater braking power.

Radiators: The RX 300 has new radiators that have been redesigned to offer a greater steering angle and optimised cooling. 

Final ratio: the rear sprocket has 49 teeth, up from 48 for lightning-fast acceleration. 

Chain: The o-ring chain is lighter and smoother than the previous one, helping make a difference on the track.

BETA RX 300 2t

Engine and exhaust: a new engine adds to the extensive frame and suspension changes for MY2025 and brings the performance of the RX 300 to the top of its class. The totally new engine consists of a new cylinder, a new head with greater compression and modified intake crankcases to increase ventilation. The result is a power unit with significantly more power than the previous model; while maintaining the renowned low-speed power of the 300 2T, the peak maximum power at high speeds has also increased. The redesigned 5-speed gearbox helps get the power to the ground, with specific gear spacing for MX use, and a stiffer spring that increases the preload on the clutch pack to prevent slippage. This new platform is perfectly tuned with dedicated mapping, new carburettor calibrations (Keihin PWK 38), and an adjusted power valve. The exhaust system, also completely redesigned, offers a dedicated expansion chamber and shorter silencer. Changes shared between both models:

Silent handlebar block: new silent blocks reduce vibrations and raise the handlebar by 5mm compared to the previous model, aiding in rider grip, control and performance. 

Footpegs: The range features new, less bulky footpegs with enhanced grip performance, providing greater control at all times. 

Swingarm: The rear wheel axle is reinforced and now 22mm in diameter (+2mm). This new component guarantees greater stiffness and torsional resistance, resulting in precise bike handling even in the toughest conditions.

Engine maps: Both RX models are equipped with two specific engine maps (wet/dry), while the RX 450 also has traction control (off/on) to manage significant power in all conditions. The button to select the map and TC is located on the handlebar pad. The RX 450 is delivered with four different pulleys to improve the throttle response. 

Availability: September Pricing: To be announced closer to arrival date.

For more info go to www.betamotor.com.au