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Overview:
In 2024, Beta launched the 450 RX model that would show off the talents of the engineering team based in Florence, Italy. The 450 RX 4 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. The 2025 RX model continues the Beta Rideability mission in Motocross. Rideability is the smoothness, ease of handling, and overall comfort experienced on a Beta Motorcycle. It encompasses factors such as throttle response, suspension performance, ergonomic design, and stability all contributing to a seamless and enjoyable riding experience. Rideability is the perfect balance of power and agility that provides riders with confidence inspiring control and effortless maneuverability, resulting in a gratifying ride, no matter the conditions.
The 2025 450 RX model received updates bringing it closer to perfection than ever. Updates to sharpen the model’s weapons, ready to do battle on MX tracks throughout the USA. An even-stronger rear aluminum subframe, suspension upgrades, as well as a more powerful lithium battery are just a few.
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Features: Updated rear subframe that has been reinforced to add stiffness and strength in key areas, updated valving in the rear shock for better overall performance, new lithium battery to ensure quick starts, 51 tooth rear sprocket for quicker spin-up of the power delivery, XTrig FlexFix handlebar mounts, larger rear axle diameter to reduce flex and provide better durability, five speed transmission, upgraded footpegs with enhanced grip and less bulk, updated engine mapping with latest setting tested by Beta race team, MAP switch and tractional control to adjust power delivery, three throttle pulleys with different ratios come standard with the 450 RX to allow riders to configure settings to their liking, electric starter, and easy access air filter box.
Handlebar Mounts
XTrig FlexFix isoelastic bar mounts reduce rider fatigue and vibration. Also allows for flexibility in handlebar adjustment
New Aluminum Sub Frame
Similar to the 450 RX the sub frame on the 300 RX is fabricated from aluminum for more strength.
Footpegs
Enhanced grip performance while being less bulky so rider can maintain control at all times
New Bodywork
Along with the aluminum sub-frame, the rear plastic is now a three-piece design. A new, smaller fuel tank (1.8 gallon) 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.
Engine
Updated Cylinder porting and matched cylinder head along with new ignition timing has increased the bike's overall power. The engine pulls harder and longer
Frame
Dedicated for motorcross 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.
Exhaust
An updated expansion chamber attached to a shorter silencer specific for moto.
Suspension
Closed cartridge 48mm KYB front fork and the rear shock have been updated with new valving for better overall performance. 50mm shock body reduces the oil temperatures under extreme use during long motos.
| MODEL | 450 RX |
| ENGINE TYPE | Single cylinder, 4 -stroke, liquid cooled, 4-valve with electric start. |
| BORE | 97mm |
| STROKE | 60.8mm |
| DISPLACEMENT | 449.3cc |
| COMPRESSION RATIO | 13.5:1 |
| VALVE TRAIN | Finger followers w/ shim adjustment |
| IGNITION | Dual-Map Kokusan with Traction Control |
| SPARK PLUG | NGK LKAR8A-9 |
| LUBRICATION | Twin Oil Pumps w/Cartridge Filter & Separate Compartments For Engine & Transmission |
| FUEL SYSTEM | 46mm Throttle Body |
| CLUTCH | Hydraulic, adjustable diaphragm multi-plate clutch |
| TRANSMISSION | 5 Speed |
| FINAL DRIVE | DID drive chain |
| FRAME | Molybdenum steel / Double Cradle w/ push button seat and quick air filter access |
| WHEELBASE | 58.4" |
| SEAT HEIGHT | 37.2" |
| GROUND CLEARANCE | 13" |
| FOOTREST HEIGHT | 16.1" |
| DRY WEIGHT | 229 lbs |
| FUEL TANK CAPACITY | 1.8 US Gallons |
| FRONT SUSPENSION | 48 mm KYB AOS closed cartridge fork, adjustable compression & rebound |
| REAR SUSPENSION | KYB 50mm body with adjustable rebound and high/low speed on compression adjustment |
| FRONT WHEEL TRAVEL | 12" |
| REAR WHEEL TRAVEL | 11.8" |
| FRONT BRAKE | 260 mm floating rotor |
| REAR BRAKE | 240 mm rotor |
| FRONT/REAR RIM | 21" (Front) 19" (Rear) |
| FRONT/REAR TIRE | Maxxis |
| SPECS | *Specifications subject to change without notice |
