FIRST LOOK: 2025 BETA RX RANGE

The Beta RX450, hailed as the first four-stroke motocross bike by the Italian manufacturer based in Rignano sull’Arno, marks a significant milestone in motocross engineering. While the RX300 2T initially served the motocross segment with its enduro roots, its success and insights gained from the RX450’s championship journey have driven the Tuscan brand to transform the RX300 into a dedicated motocross powerhouse.

For the 2025 model year, both the RX300 and RX450 have undergone extensive upgrades. The RX300 boasts a new engine, suspension, and frame that firmly set it apart from its enduro origins, transforming it into a motocross-specific machine. Meanwhile, the RX450 features enhancements aimed at sharpening its track performance.

Get the full rundown below from Beta’s Australian PR below.

2025 RX450 CHANGES:

Rear sub-frame and air filter housing: while the rear sub-frame’s geometry and air filter housing remains unchanged, the structure has been suitably reinforced in a series of points that stiffen and strengthen it, maintaining lightness and its ability to absorb impacts. Access to the filter remains on the left side of the bike and is extremely easy and intuitive to use, as well as being tool free.

Suspension: the KYB fork and single shock package receives 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 and stability that instils confidence in every rider, regardless of their level.

Battery: a new lithium battery has been mounted on the RX450, 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, improving the response coming out of corners as well as allowing the engine to build RPM quicker.

Graphics: while the plastics and new tail section remains unchanged, new, more sleek and aggressive graphics have been introduced, which further highlight the racing pedigree of this model.

2025 RX300 2T CHANGES

Frame: the RX300 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 at speed. The engine mounts and position is different from the enduro models and provides excellent balance on the track.

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

Fork: The Kayaba (KYB) 48mm forks has greater travel than the enduro models, and receives new calibration that creates the perfect set-up together with the new single Kayaba shock, delivering 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 that 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 RX300 sees new radiators that are 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 non o-ring chain is lighter and smoother than the previous one, all helping to make a difference on the track.

Engine and exhaust: a new engine adds to the extensive frame and suspension changes for MY2025 and brings the performance of the RX300 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 results of this is a power unit with significantly more power than that of 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 with 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 adjusted power valve. The exhaust system, also completely redesigned offers a dedicated expansion chamber and shorter silencer.

RX300/RX450 SHARED CHANGES

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 sees new, less bulky footpegs with an 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 a bike that is precise in its handling, even in the toughest of conditions.

Engine maps: both the RX models are equiped with with two specific engine maps (wet/dry), while the RX 450 also has traction control (off/on) to manage the significant power in all conditions. The button to select the map and TC is located on the handlebar pad.

The RX450 is delivered with four different pulleys to customers the throttle response.

Availability: September

Pricing: To be announced closer to arrival date.