Beta has unveiled its 2027 RX motocross line-up, and the big news is the arrival of the long-awaited RX 250 4T. After spending 2026 developing and racing the bike at the highest levels of competition, Beta’s all-new quarter-litre four-stroke is finally heading into production, giving the Italian manufacturer its most complete motocross range to date.
Joining the RX 250 4T for MY27 are updated versions of the RX 450 4T, RX 250 2T and RX 350 2T, creating a four-bike range that covers everything from high-revving four-strokes to torque-rich smokers.
The launch marks another significant step in Beta’s motocross ambitions. While the company has built a strong reputation in enduro, the RX range continues to evolve into a genuine motocross contender, with Beta’s “RideAbility” philosophy remaining at the core of every model.
ALL-NEW RX 250 4T ARRIVES
The headline act is undoubtedly the RX 250 4T, a motorcycle Beta says was designed from the ground up to challenge the best bikes in the class while remaining manageable for everyday racers.
Unlike many manufacturers that adapt existing platforms, Beta has developed an entirely new engine and chassis package specifically for the RX 250 4T. Nothing is shared with the current RX range.
At the heart of the bike is a compact DOHC engine featuring a unique architecture that differs significantly from the RX 450 4T. The cam chain is positioned on the right-hand side and driven via a gear connected to the water pump shaft, while a hydraulic tensioner helps minimise noise and vibration at high rpm.
Rx 250 4t Engine 
Mass centralisation was a major focus during development, with Beta claiming the engine comes in around 1.5kg lighter than the current class benchmark. Thin-wall aluminium crankcases and magnesium engine covers help achieve the weight savings without sacrificing durability.
Performance-wise, the new engine is aimed squarely at the sharp end of the 250F category. A dual-injector fuel-injection system uses one injector at the throttle body and another at the airbox sleeve, helping deliver crisp bottom-end response while maintaining strong top-end power.
The engine also features forged steel crank journals, a forged connecting rod, roller main bearings and a Formula 1-inspired “box-in-box” piston design to ensure reliability at high engine speeds.
Cooling has been completely redesigned using CFD analysis, with a compact closed-type impeller system eliminating the need for vulnerable external coolant pipes.
The RX 250 4T receives a five-speed gearbox designed specifically for the new engine, while the clutch borrows heavily from the proven RX 450 4T setup.
Handgrips 
KYB Fork 
KYB Fork 
New Button
FACTORY-STYLE ELECTRONICS
For the first time on a Beta four-stroke motocross machine, the electronics package has been directly inspired by the company’s race program.
The RX 250 4T comes equipped with:
- Five-level Launch Control
- Quick Shift
- Two-level Traction Control
- Dual engine maps (Dry and Wet)
All functions are controlled through a newly designed switch cluster integrated into the handlebar pad, protecting the controls from crash damage while keeping them easily accessible during a race.
NEW FRAME AND KYB SUSPENSION
The chassis has been purpose-built around the new engine, featuring dedicated geometry and a unique mounting arrangement that differs from the 450.
While the RX 450 4T uses a central cylinder-head mount, the RX 250 4T employs side-mounted head stays to increase torsional rigidity while maintaining vertical flex characteristics. Beta says the result is improved cornering precision, greater traction and enhanced stability.
Suspension duties are handled by a KYB package comprising a 48mm closed-cartridge fork and 50mm rear shock, with settings tailored specifically to the lighter and more agile 250 four-stroke.
RX 450 4T GETS ELECTRONIC UPGRADES
The flagship RX 450 4T receives a series of refinements rather than a complete overhaul for 2027.
The biggest changes focus on electronics and power delivery, with the bike now receiving the same Launch Control and Quick Shift functions as the new 250F.
Traction Control has been recalibrated for smoother intervention, while both engine maps have been revised to improve overall performance.
Beta has also updated the throttle body with a new tapered design that improves airflow efficiency, resulting in sharper throttle response and more controllable power delivery.
TWO-STROKES CONTINUE TO EVOLVE
Beta’s RX 250 and RX 350 two-strokes remain in the range, each receiving targeted improvements.
The RX 350 2T gains a completely new piston designed to reduce reciprocating weight and improve engine response. Combined with new PVD-coated piston rings, Beta claims the changes deliver an increase of approximately 1.5 horsepower.
Meanwhile, the RX 250 2T receives revised gearing, moving from a 13/50 combination to a taller 14/51 setup. The change is aimed at creating smoother gear progression and improved traction, particularly on fast tracks and corner exits.
Both two-strokes also receive updated silencer internals, redesigned handlebar protection and new-generation Dunlop tyres that offer improved traction while reducing overall weight.
UPDATES ACROSS THE RANGE
Every RX model benefits from a number of common updates for 2027, including:
- Reinforced chain guide for improved durability
- Redesigned front sprocket guard
- Softer-compound Beta grips
- New red-and-black graphics package
- Revised handlebar pad design
The proven aluminium subframe, tool-free air filter access, KYB suspension package and Nissin braking systems remain unchanged across the range.
ARRIVAL DATES
Australian riders won’t have long to wait.
The RX 250 2T, RX 350 2T and RX 450 4T are scheduled to arrive in dealerships from September 2026, while the all-new RX 250 4T will follow in October 2026.
Pricing is yet to be announced, with Beta Australia expected to release local pricing closer to launch.
For Beta fans and motocross racers alike, the RX 250 4T represents one of the most significant new-model releases from the Italian manufacturer in recent years. With a completely new platform, modern electronics package and genuine race-bike credentials, it gives Beta a serious player in one of motocross’s most competitive classes.
Visit www.betamotor.com.au/ for more info.
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