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Beta USA

2026 Beta 350RX

2026 Beta 350RX

Regular price $10,290.00 USD
Regular price Sale price $10,290.00 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 model 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.

350 RX: All new for 2026, this new model replaces the 300 version for the 2026 season. New engine cases, bore and stroke, as well as a twin-plug head to ignite the special power only a big-bore 2-stroke can provide. The longer crankshaft, combined with the final gearing ratio of 14/47, provides a large amount of torque and overall horsepower that will turn some heads. This new 350 motocrosser will thrive in many different track conditions. Clearly in a class of its own!

250-350 RX 2 Stroke

Engine: Both engine capacities received a completely new, purpose-built engine. The 350 RX was designed to obtain the greatest linear power delivery and give riders the option to exploit the great power available when needed, while the 250 RX can count on explosive performance, ready to compete in races under all conditions.

» Head: The first noticeable difference when looking at the new engines is certainly the dual-spark-plug head on the RX 350 2Str, while the 250cc still relies on a classic single spark plug. This differentiates the two motorcycles’ character even further, with the 250cc providing riders with a high-revving engine that competes with the likes of 250 4Str bikes, while the 350cc manages to keep a greater torque and rounded delivery, enhancing its ease of recreational use, at lower speeds while still provides enough overall horsepower for race use.

» Cylinder, piston, and power valve: to further differentiate the two bikes, apart from the obvious engine capacity, Betamotor engineers worked on new cylinders and pistons, designed specifically for each engine. The power valve, too, was calibrated accurately to manage the two deliveries by adopting different springs.

» Crankshaft: the two motorcycles have a different stroke, with the 250cc reaching 72mm and the 350cc reaching 73.6mm.


Beta Built single cylinder, 2-stroke, liquid cooled, with BPV power valve system and counter balancer, electric start with back-up kick starter sold as an option

78mm
73.6mm
351.7cc
12:45:1
Beta Progressive Valve (BPV)
AC-CDI Kokusan
Dual MR7VBI-8
Pre-Mix
Keihin PWK 38mm
Wet Diaphragm-style
5 Speed
O-ring chain
Molybdenum steel / Double
Cradle w/ quick air filter
access
58.7"
37.2"
13.4"
16.6"
220.5 lbs (wet weight, no fuel)
1.5 US Gallons
48 mm KYB AOS Closed Cartridge with adjustable compression & rebound

KYB 50 mm body with adjustable rebound and high/low speed on compression adjustment


12.0"
11.8"
260 mm floating rotor
240 mm rotor
21" (Front) 19" (Rear)
80/100 120/80


*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 SUPPORT.


$10,290.00
MSRP + Tax

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