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Beta USA

2026 Beta 450RX-F

2026 Beta 450RX-F

Regular price $6,989.00 USD
Regular price Sale price $6,989.00 USD
Sale Sold out

Built for Any Moto, Ready for Every Gate.

 

Beta has added two new motocross models to join the big brother 450 in the RX range. All-new 250 and 350 RX 2 strokes are the new bosses in town! Beta’s 450 RX has been racing on the world MXGP tour for four years and the AMA USA Supercross series for two and has proven to be a serious contender. The Italian Beta engineers decided to “Go Big” for 2026 and add not only a 250 cc bike to race in the proper classes but also added a 350 RX smoker as well for everyone else! All Beta MX models are designed with the trademark RideAbility in mind. A motorcycle that is overall easier to ride.

450 RX: Proven through races all over the world, including the USA Supercross series and MXGP. The 450 RX provides a ride like no other, quick turning yet stable; powerful yet easy to ride, are just a few things the press is saying about the 4-stroke model. An engine with enough power for a top-level pro rider while providing the right amount of power to the amateur as well. For 2026, the 450 RX receives a new cylinder head with improved flow that provides even more power. This, along with a matched intake manifold and a new exhaust, means the 450 will still bark with power but do it in a quieter way. A redesigned counterbalance shaft to reduce vibration and new mapping to go with the new cylinder head and exhaust.

Engine: The 450cc engine development was focused on providing riders a significant performance increase compared to the previous model, offering a stronger torque curve that can be used under all conditions. This achievement was possible due to a new cylinder head with a performance-enhancing piston, a new intake manifold, and a different exhaust system. The head’s overhaul - developed through CFD analysis and many flow bench calibrations - includes an improved intake duct to enhance air circulation inside the engine. The new manifold, following the flow line, has a longer internal horn to improve the tuning of pressure waves, and thus increase their fill while intaking air. The piston includes new coatings to reduce friction and improve its performance. A newly designed counter balancer was introduced to contain vibrations and reduce rider fatigue.

Exhaust system: the head-pipe has been redesigned to create a greater flow and to provide increased power. This new 4-stroke exhaust system is completed by a silencer, redesigned with HGS to contain the DB output, in line with the new racing standards.

Maps: Updated to perform better with the new motor configuration, with renewed start-up and limiter strategies.



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
58.1"
SEAT HEIGHT
37.2"
GROUND CLEARANCE
13.2"
FOOTREST HEIGHT
16.6"
DRY WEIGHT
230.4 lbs (dry weight, no fuel)
FUEL TANK CAPACITY
1.5 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
80/100  |  110/90
SPECS
*Specifications subject to change without notice Additional information on all models including manuals, accessories, and
parts books are available online at www.betausa.com under the support tab
**This model is for competition use only


$10,990.00 | Sale Price $6,989.00
MSRP + Tax

Destination Fee $589.00
Build & Prep Fee $147.00
Documentation Fee $89.00
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