The 2024 Beta RX 450 is officially the first four-stroke motocross bike built by the Italian manufacturer. The Beta MX bike is based off of the race prototype that competed in the MXGP World Championship for the last three years.
A race-ready bike in all respects, specifically designed for motocross tracks, the design is completely new from the ground up: the frame, engine and all of the components are of the highest level, and developed with the project brief in mind: to bring new horizons of RideAbility to the MX world.
Beta motorcycles are designed by a team of engineers based in Florence, Italy with a mission to provide all riders with a motocross bike that is easier to ride, while still providing the highest level of performance.
Debuting in the MXGP circuit just a few years ago, these early one-off models provided the base layout and design for the production model and will see the 2024 Beta RX 450 joining its younger brother the RX 300 2T on race tracks all over the world.
The technical design of the 2024 Beta RX 450 is totally new and features:
Frame
Designed from the ground up as an all-new frame that is specifically designed and dedicated for motocross use. The main spar of the frame is wider in design to withstand the stresses from repeated landings, making it much stiffer overall, yet supple enough for cornering. This translates into a precise chassis that provides a planted feeling in corners and a light feeling while in the air.
Rear sub-frame and filter box
The RX 450 has a new aluminium rear sub-frame which provides rigidity to the bike despite its light weight, providing the strength needed for the demanding needs of motocross. This new component is perfectly integrated with the new air filter box and is all-new for the RX 450. The new filter box and air intake, combined with the new 46 mm throttle body, provide a significantly different air flow than that required by an enduro bike, creating optimum air flow to keep up with the performance of the new engine. Access to the filter remains on the left side of the bike, and is extremely easy and intuitive, as well as being tool-free.
Plastic parts
While the front shrouds, recently redesigned for RR models as well, remain unchanged in their form, the rear features a new sleek and aggressive tail which, not being a structural component, fits into the new aluminium rear sub-frame and, as previously mentioned, allows access to the filter box via a convenient connection. The fuel tank is a smaller design and has a capacity of seven litres.
Fork and Shock
Kayaba, with 48 mm stanchions at the front and 50 mm piston at the rear. Both components are completely adjustable, and represent an ideal compromise between rideability and performance, thanks to continuous development on the track. The main difference in the suspension compared to the enduro models is the greater travel of the front fork, with specific calibration for motocross, while the shock is completely new. The shock is larger than the one the RR models are equipped with, which provides greater support on landings thanks to greater hydraulic damping, and more consistent performance with demanding use.
Wheels and brakes
The blue anodised wheels are 21” at the front and 19” at the rear, with 90/100-21 and 110/90-19 Maxxis tyres, while the braking system is by Nissin with floating callipers and a 260mm disc on the front and 240mm at the rear. The front brake calliper is a smaller, more modern design. Also lighter than those previously used on Beta models, which provides noticeably more incisive performance when letting off the throttle at the limit, while on the rear the new brake master cylinder has a reservoir designed to leave more space for the exhaust layout.
Engine
The engine, designed specifically for motocross use, has been developed in close partnership with the Official MXGP Team. The gearbox is five speed, with dedicated ratios, while the clutch (with diaphragm springs, and three adjustable positions) has been designed to withstand the stresses from the engine’s high power output, while offering a light clutch pull at the lever. The weight and dimensions are particularly compact, as the components required for motocross use have been pared down to the minimum.
The crankshaft and countershaft are new, as are the cylinder, piston and timing system, allowing a compression ratio of 13.5:1 to be achieved.
Engine maps
In the wake of the recent introductions on the RR models, the RX 450 4T is also equipped with two specific engine maps (wet and dry) and four levels of Traction Control (on/dry, off/dry, on/wet, off/wet) to help manage the bike’s significant power in all terrain conditions. The button to select the map and Traction Control is located on the handlebar pad.
Other notable features
The handlebar controls have been reduced to a minimum, as has the electrical system. On the right-hand side is the start button, while the button to shut off the bike is on the left.
There are then some special components which enhance the bike’s trim level as well:
Chain tensioners in red alloy
Blue anodised Excel rims
Red chain guide
Red anodised dual-material sprocket
Black alloy footpegs with steel pins
Rounding off the package are brand-new graphics, featuring typical Racing colours, but lending a unique flavour to the Beta’s first four-stroke motocross bike.
The RX 450 will be delivered with a customised stand and four different throttle pulleys, to customise the throttle response.
