FIRST LOOK: BETA’S 2027 MX MODELS

Beta reveals full details of its all-new 250cc four-stroke MX weapon, the RX250 4T. It spearheads a four-model range for 2027, which reinforces just how committed the Italian brand is to claim a bigger share of the hotly contested motocross market.

Just how serious is Beta about becoming a major player in the MX market segment? Well, aside from the fact they blindsided everyone blast year by introducing two two-strokes – a 250 and 350cc machine – the Italian manufacturer has shown no signs of slowing down with its MX-model investment. For 2027, not only has Beta brought targeted refinements to its three existing MX machines; but they’ve also released the first ever 250cc four-stroke MX bike to bear a Beta badge. And the thing uses a purpose-built chassis and engine that shares nothing with the other three models!

This all-new RX250 4T (a prototype version of which we showed you a few months back) spearheads Beta’s recently revealed 2027 RX range, which continues to follow a “high-performing and easy to ride” design philosophy. The all-new RX250 4T is due to arrive in Aussie dealers in October, with the 250/350 2T and 450 4T expected in September. Pricing is yet to be announced.

So, meantime, let’s get into the design and component nitty-gritty of Beta’s landmark quarter-litre MX machine, and then take stock of the targeted refinements that have been made to the rest of the 2027 RX range. What follows is an excerpt from Beta Australia’s PR…

Beta has confirmed its motocross range for the 2027 model year, headlined by the bike riders have been waiting for: the all-new RX250 4T. After cutting its teeth in high-level competition through 2026, the 250 four-stroke now joins the production line-up, giving Beta Motorcycles four distinct MX models for MY2027: the new RX250 4T, the established RX450 4T, and the RX250 and 350 two-strokes introduced last year.

The one constant is the philosophy behind it all. Every Beta is built to be both high-performing and easy to ride – a bike that pulls the best out of whoever’s on it, with an engine and chassis matched so the performance is always something you enjoy, never something you fear. Beta calls it “RideAbility”.

2027 RX250 4T – PURPOSE BUILT!

The long-awaited 250 4T motocross offering from Beta has arrived. The RX250 4T was built to win at a world-championship level while staying friendly enough for the weekend racer – featuring strong, progressive power, serious traction, and handling that rewards rather than punishes. Engine and chassis share nothing with the existing range; both are purpose-built for the new RX250 4T.

It’s a race-ready four-stroke developed to sit alongside the popular two-stroke, broadening Beta’s 250 line-up for riders who want four-stroke character. Strong traction, sharp handling and easy power management make it a genuine option for anyone chasing top-level performance with the precision and consistency to back it up – whatever the conditions.

And it’s all-new. The RX250 4T doesn’t borrow from the rest of the range; it solves things its own way, with technical solutions specific to this model.

ENGINE: The all-new 250 4T engine features a DOHC layout with the cam chain located on the right-hand side – different to the RX450 4T engine platform. The timing system uses a quiet Morse-type chain driven by a gear linked to the water-pump shaft; the tensioner is hydraulic, ensuring effective damping of noise and vibration, while the compact layout guarantees reliability even under the most demanding conditions and RPM levels.

The target was a new class benchmark for size versus performance. Every component was placed with mass centralisation in mind, and the finished engine lands about 1.5kg under the current class standard. This is achieved by:

Main cases are die-cast with a special aluminium process that allows extremely thin walls without giving up strength;
Magnesium alloy engine covers, including the cylinder head cover; and
On the performance side, the 250 4T sits with the best in class. A dual-injection set-up – one injector on the throttle body, one on the airbox sleeve – ensures optimal air-fuel mixture management across the entire rev range: crisp response down low, strong and usable power up top. And the top-end is where this engine lives. The rev ceiling is set very high, with high-performance components ensuring reliability:
- Crankshaft journals in dedicated forged steel, spinning on two roller main bearings.
- Forged conrod with a plain bearing to handle the pressures and speeds, keeping inertia, balance and strength where they need to be.
- Box-in-box piston architecture – the same thinking used in Formula 1 engines.

Cooling was developed with CFD analysis to maximise heat exchange and minimise pressure losses. Unlike the 450, it runs a closed-type impeller for better flow in a smaller package, with no external piping to snag or crack. Electric start, a single shared oil supply for engine and gearbox, and an exhaust designed around nothing but power output, round out the package.

GEARBOX & CLUTCH: The clutch carries over from the RX450 4T – seven friction plates, six steel – with a new integral bell housing for the primary driven gears and an updated hydraulic actuation unit. The five-speed box is all-new for this engine; its geometry trimmed for weight and size without giving up strength. Light, compact, quick to engage: a racer’s gearbox.

ELECTRONICS: For the first time on a Beta four-stroke motocross bike, the electronics come straight from the race team:

Launch Control (five levels)
QuickShift
Traction Control (two levels)
Dual engine mapping (dry, wet)

It’s all run from a redesigned control panel that’s integrated into the handlebar pad – easy to reach mid-moto, and with the switches kept off the bar where a crash can’t claim them.

FRAME & SUSPENSION: The frame was drawn around the new engine, with dedicated geometry and lower tubes that hug the cases for a compact package. Where the RX450 4T uses a central engine-head mount, the RX250 4T utilises side- mounted head stays – delivering more torsional stiffness, with the same vertical flex. The result is a new balance between cornering precision and suspension performance, generating greater traction and stability.

The RX250 4T receives a KYB suspension package that features a 48mm closed-cartridge fork, and a 50mm shock with settings developed for the lighter and sharper 250 4T.

2027 RX450 4T – SMARTER & SMOOTHER

Development of the MY27 RX450 4T is centred on electronics and power delivery. The big-bore picks up the same QuickShift and Launch Control as its smaller sibling, the RX250 4T, while Traction Control has been refined to step in more precisely and progressively. Both engine maps have been recalibrated to dig more out of the engine.

Launch Control (five levels)
QuickShift
Traction Control (two levels)
Dual engine mapping (dry, wet)

It all runs from the same redesigned control panel, built into the handlebar pad.

The throttle body gets an update too: a new tapered design that flows more air with less turbulence. The result is crisper throttle response and smoother, more adjustable power.

2027 RX250 & RX350 2T – TWO PERSONALITIES, SHARPENED

Beta’s 250 and 350 two-strokes have come in for targeted development from Beta Motorcycles, fine-tuning the handling and performance – each with its own distinct character. The RX250 2T is the snappy, feisty one: a true race-ready weapon. The 350 is the more progressive all-rounder, versatile and happy pulling longer gears at a relaxed pace with plenty of torque. Two very different personalities, built to suit two different riders.

RX350 2T: For MY27, the RX350 2T gets a new piston, designed from scratch to optimise weight and performance. The weight it saves cuts inertia noticeably, sharpening engine response, while new PVD-coated rings reduce friction. These modifications see an increase of around 1.5hp.

RX250 2T: The final drive moves from 13/50 to 14/51, lengthening the overall ratio. The result is smoother gear progression – most noticeable on fast sections and corner exits, where you want traction and plenty of drive.

SHARED MODS (250 & 350 2T):

Silencer: Both engine sizes get updated silencer internals, built to better withstand the punishment of hard motocross use;
Dunlop tyres: Like the four-strokes, the two-strokes now run new-generation Dunlop rubber – strong on traction and performance, but lighter than before, and the handling shows it; and
Handlebar protection: The bar pad has been redesigned for more rider protection and to bring the two- strokes into line with the four-stroke family and still houses the map-select button.

SHARED UPDATES – ALL 2027 RX MODELS

Chain guide: Reinforced to resist mud, sand and impacts, for a more precise and durable drivetrain.
Front sprocket guard: Redesigned for superior protection against impacts and debris, and added rider safety – legal under even the strictest competition regulations;
Grips: A softer compound for better comfort and control over a hard moto, embossed with the Beta logo; and
Graphics & colours: A new red-and-black livery – aggressive and contemporary, timed to mark the arrival of the long-awaited RX250 4T.