Downdraft Intake and Exhaust Layout

The DOHC cylinder-head design lets our engineers straighten out the bike's intake and exhaust tracts that have been optimized to improve power and response. The intake is shorter and just about arrow straight, and the exhaust flows more efficiently too. No athlete’s going to win a sprint if they try to run while holding their breath, and it’s no different with your bike’s engine. You’ll experience both, more power and better throttle response.

Big Bore/Short Stroke

The 79 mm bore and short 50.9 mm stroke let our engineers create a high-revving engine with plenty of room for large valves. The engine breathes and revs—the two keys to making power.

Dual-Exhaust System

The dual-exhaust system is light, compact, and positioned close and low in the frame to take weight off the rear end and bring more mass to the bike’s center for improved handling. It also allows for more airflow, and that equals added power.

Total Air Management

Total air management means complete attention to how efficiently air gets through the intake, through the head, and out the exhaust. Eliminate losses here, and you make more power everywhere. And the best part? It’s free horse power—you just need a bike with smart design.

Bridged-Box Piston

Coordinated to work with the new cam profile and combustion-chamber shape, it’s the final piece to the engines performance package. The bridged-box design features a reinforcing structure between the skirts and the wrist-pin bosses that helps enable the high redline.

“H” Section Crank

Look closely at the crankshaft profile and you’ll see its “H” cross-section design. What’s up with that? Just like a structural “I” beam in an aircraft wing or a skyscraper, it boosts strength and cuts weight over a conventional crank’s shape—a big deal when you consider this part spins at over 14,000 rpm!

Gradual Pipe-Bend Radius

Notice how the dual exhaust pipes make gradual, large-radius bends out of the head, then flow straight back to the mufflers with no abrupt angle changes. Getting the exhaust out of the engine—while still maintaining a tuned exhaust length, is the key to power, while the pipes’ low mass and twin-silencer design optimize the center of mass for superior handling.

Clutch Design and Materials

The clutch uses two different types of friction material. Why? The clutch can handle the increased power of the engine without being any larger. The lighter rotating weight is directly related to how fast the engine revs.

Lithium-Iron-Phosphate Battery

Like the rest of the bike, the Lithium-Ion battery is both super light and high performing, weighing in at less than half the weight of a conventional lead-acid battery.

High-Capacity Resin Fuel Tank

For longer cross country loops, the CRF250RX features a bigger fuel tank that holds a full 8.5 litres.

Engine Oil Scavenge Pump

Deep in the engine, there’s a special oil scavenge pump. While you may never see it, it helps keep the overall design compact.

Shared Engine/Gearbox Lubrication

The bike uses a shared engine/transmission oiling design. Why? Combining the two systems shaves weight and helps make the engine more compact, especially when it comes to placing the right-side cam drive and the clutch so close together.

Double-Spray Injector Settings

The bike's fuel-injection system sprays twice per intake cycle. That helps increase fuel atomization without adding the weight or complexity of a second injector. The better fuel atomization means more power in the midrange and on over rev—you’ll feel it the first time you ride.

Cam Profiles

With input directly from our HRC factory team, we’ve changed the intake cam profiles to work with the new valves. You should feel better bottom end torque and power, while still retaining the bike's screaming peak.

Throttle Body

With a 44 mm venturi designed to speed up airflow, the bike's throttle body really reaps benefits at low engine operating speeds. You get power and snap, right now.

High Redline

With our better-breathing DOHC design and the big-bore/short-stroke engine, the rev limit is very impressive. The same goes for peak power and peak torque.

Showa Spring Fork

The 49 mm Showa fork features a conventional spring design that helps increase the front-suspension precision, handling and feel. The 39 mm piston diameter and 25 mm rod diameter guarantees a plush feel and supple action.

Low Rear Shock Mount

With its low rear shock mount on the frame, the bike benefits from both a lower center of gravity as well as chassis stability.

Short Swingarm

The short swingarm helps make it light, and also helps give the bike better rear-wheel traction, important considering how much power you have on tap. The swingarms design focuses on improved stability and handling, while still reducing the bike’s unsprung mass.

Dunlop Geomax Tires

The CRF250RX’s Dunlop Geomax tires are specially designed for cross country use. The AT81 tires are spec’d at 90/90-21 for the front and 110/100-18 for the rear. You read that right: the CRF250RX rolls on an 18-inch rear wheel.

260 mm Front Brake

The large front-brake disc measures a whopping 260 mm, with improved rear brakes that perform like never before. You get great brake feel and a pattern that cuts down on weight. Front and rear brake-disc guards are part of the package too.

Smooth Styling

Blending the body panels does more than just make the bike look smooth, fast, and stylish. It also helps you move around on the bike while riding. Nothing wrong with smooth, fast, and stylish, though.

Rear Subframe

The subframe uses extruded rear members that produce a 20-percent reduction in weight versus the previous generation. Since that weight comes off the top of the bike, it also contributes to the low center of gravity.

Sidestand

Real cross country bikes need a sidestand, and we’ve given the CRF250RX a great one. Tucked up high and out of the way, this forged alloy piece is just another example of how the CRF250RX gets it right.

Black Rims

They may not help you go faster, but the black D.I.D® rims sure look good.