2017 KTM 250 EXC-F
Fill an agile, state-of-the-art chassis with an engine delivering class-leading power and torque. Then dress it with top class components, ensuring that the lively little 4-stroke maintains its edge over the competition. Finished. First. And it’s easy on the stomach for amateur explorers, while still satisfying fame-hungry pros. Eat that, adversaries.
- Engine: The new 250 EXC-F engine has been redesigned in order to make the new powerplant more compact and lighter, while delivering class-leading torque and power figures over the entire rev range. The new architecture with an optimized shaft configuration makes the engine 20mm shorter, which contributes to the bike’s mass centralization and effortless rideability. Another major benefit of the new design is the weight reduction by 1.5kg, down to hardly 27.6kg. And that’s including the comfort of an electric starter. The power curve now reaches for the sky over the entire length of the rev range, begging for another gear at 12,800rpm. This makes the new 250 EXC-F brilliantly suited to both amateur riders as to pros at the peak of their ability. And it’s Euro IV homologated, so the planet will love you for it.
- Cylinder Head: The centerpiece of the compact DOHC engine is this cutting-edge cylinder head. It features two overhead camshafts, which have lost 150g, with friction-optimized finger followers boasting a 30% harder DLC coating and a reworked timing drive. Four lightweight titanium valves and high-flow ports maximize the flow rate for an optimal power band and outstanding performance across the seemingly endless rev range of 12,800rpm. By then, you’re way past the sound barrier. Two new lateral brackets allow an efficient fixation of the engine to the frame and reduce vibrations.
- Crankshaft: The 250 EXC-F’s crankshaft utilizes a 6mm shorter connecting rod, which makes for an overall compact and lightweight engine with a snappy power delivery. A plain big-end bearing with two force-fitted bearing shells runs directly on the crank pin. This design is a major rerequisite for the extremely high engine speeds and the unrivaled maximum power of this 250cm3 engine. Not only that, it also enhances the engine’s durability, allowing long crankshaft service intervals. To you, that’s less time in the workshop and less money out of your pocket. Which is nice.
- Electric Starter: The 250 EXC-F is fitted with an electric starter as standard, which is a clear advantage when things get gnarly. A strong starter motor made by Mitsuba powered by a reliable lithium ion battery and KTM’s proven starter drive will fire up your all-star time and time again at the push of a button.
- Engine Cases and Covers: The completely new design of the die-cast engine cases allowed for a much more centralized shaft configuration, moving the crankshaft closer to the bike’s center of gravity, while the clutch shaft position moved 11.1mm back and 26.9mm up. This shortens the engine by another 2cm. All hail mass-centralization! Newly designed engine covers feature an advanced surface structure in order to reduce the wear caused by the rider’s boots. Because that would be a pity.
- Transmission: The new engine is fitted with a smooth, tailor made six-speed Enduro gearbox, running like clockwork thanks to a special low-friction coating on the shift forks. Its advanced ´No Dirt´ gear lever design prevents dirt from blocking the joint of the lever and guarantees a safe activation of the transmission. All 4-stroke engines are fitted with a gear sensor that sync the power curve to the gear you’re in and the surface you’re on. Yes, smart is sexy. And fast.
- Engine Management System: The state-of-the-art Keihin Engine Management System with electronic fuel injection features an all-new 42mm throttle body. Thanks to its unique injector position, the engine’s response gives a whole new meaning to the word ‘instantaneous’. And to make life even easier, separate systems for cold starts and idle adjustment await you. Push the throttle back when the engine’s alive and well, and the cold start mode disengages. And with an optional map switch you can select a stronger power curve and activate the unique traction control system for maximized grip.
- Clutch: The 250 EXC-F employs the KTM-developed DDS clutch (damped diaphragm steel) with a wear-free steel basket and extremely heat resistant clutch plates. This clever design employs a diaphragm spring instead of the usual coil springs, which makes for a considerably easier clutch action. A diaphragm spring also leaves sufficient space for a damping system to be integrated into the clutch hub. The goal was traction, yes, but durability as well. On top of that, it is fitted with a lighter basket, a reworked inner hub and a pressure plate providing better oil supply and unsurpassed cooling. Of course, light operation and magic amounts of control are what make this particular clutch, a hydraulic Brembo clutch.
- Counter Balance Shaft: In order to balance the mass forces, the engine uses a multifunctional counter balance shaft, which at the same time drives the water pump and reworked timing chain. Win, win, win!
- Cylinder and Piston: Inside the shortened cylinder, with a bore of 78mm, thumps a reliable box-type piston made by CP. Its crown geometry is adapted perfectly to the high-compression combustion chamber (12,8:1), where its rigid structure and low weight shine. Thanks to tiny oscillating masses, the engine is as perky as it’s powerful.
- Weight Reduction: The main target for the KTM engineers when developing the EXC models was a massive weight reduction compared to the previous generation. The result: the current EXCs are the slimmest, lightest bikes in the Enduro scene, even though the engines are equipped with an electric starter as a standard feature, while the competition still needs to be kick-started. You can just focus on kicking ass.
- Frame: The high-tech, lightweight chrome-moly steel frame has a knack for easy handling, outlandish rideability, precise cornering and excellent stability. You can also count on high torsional rigidity and low longitudinal stiffness. This results in better absorption of the energy created from the front and rear suspension sucking up jumps and bumps. In short: more comfort and less rider fatigue. Laterally attached, lightweight engine head stays (the connection between cylinder head and frame) contribute to a reduced vibration level. Two threaded inserts in the lower cradle tubes allow for safe fixation of an optional skid plate. The engineers were able to pull off all that, while making their frame a big fat kilogram lighter than that of the lightest competitor on the market. In addition, it is easier to maintain, easier to work on and supplies more space for the tank and other components. The bike also features an extra-light subframe made of stable aluminum profiles, which tiptoes the scales at less than 900g.
- Footpegs: Sophisticated ´No Dirt´ footpegs prevent smudging up the pegs, even when digging in deep ruts. The pegs on the EXC models are 6mm higher than the ones used on SX versions, which benefits ground clearance. But you can swap them at will.
- Swingarm: This updated design allows for an optimized mounting position of the PDS (progressive damping system) shock, providing even more progressive action. Furthermore, the cast aluminum design guarantees lower weight (-220g) and perfect flex behavior. The single-component casting process also eliminates any inconsistencies and inherent weak points created by welding. And it’s better looking.
- Rear Suspension: The WP XPlor PDS is a newly developed rear shock. The PDS, the KTM proven and successful progressive damping system is kind of a KTM trademark where the shock absorber is directly connected to the upper side of the swingarm. We don’t use any linkage systems. This set-up has now been reworked with the new frame and swingarm architecture in mind. It boasts the best possible mounting geometry, provides even more progressive damping and features an all-new body with a smaller piston and a larger reservoir. The piston diameter was reduced from 50 to 46mm for reduced weight, the total length is reduced by 2.5mm and the shock stroke shrank by 4mm. In addition, it is now mounted 5mm closer to the centerline, which means nearly symmetrical loads for the swingarm and frame and more space for the exhaust. A second piston works together with a closed cup (instead of a needle) towards the end of the stroke and is supported by a progressive shock spring. It will be hard to bottom this rugged bad boy out. Still, we managed to cut its weight by more than 600g. Various machined and anodized components and a distinctive WP color trim (black reservoir, white spring, silver body) make this a valuable, high-end product compared to the roughcast bodies of many competitors. You’d almost hate to see it get dirty. Almost.
- Front Suspension: The all-new WP XPlor 48 upside-down fork is a split fork developed by WP in close collaboration with KTM. It is fitted with a spring on both sides but features separated functions for each fork leg: compression damping is fitted on the left side, while rebound is on the right. So the forks can easily be adjusted for compression and rebound with the twist of a dial on top of the fork tubes (30 clicks each). In addition, a longer and sealed hydro-stop guarantees better resistance to bottoming-out. Due to high-quality materials and a state-of-the-art production process, the new XPlor 48 fork - with approx. 300mm of travel - has outstanding response and damping characteristics and is about 200g lighter than its predecessor. A new, optional preload adjuster allows for a threefold spring preload setting without any tools. Easy as one, two, three.
- Brakes: You couldn’t brake any harder, better, faster or stronger. These high-tech Brembo babies are combined with lightweight wave discs. And the rear brake now features a 10mm longer brake pedal combined with a smaller caliper piston for better modulation. The steel-flex front brake hose enjoys better protection tube with an integrated channel for the speedo cable. First you outrun them, then you outbrake them.
- Handlebars: KTM engineers sure know how to handle handlebars. This tapered one, made of high-strength aluminum by NEKEN, features a newly developed throttle assembly with a robust aluminum body and straightforward free-play adjustment. An ODI volcanized grip sits on the right, while on the left side of the bar a comfortable ODI lock-on grip is mounted, which does not require any wire or glue to be fixed. You can now retrofit two interchangeable throttle cams, for different response characteristics to suit your specific needs. Another option is the handlebar map switch, which allows for the selection of an even feistier power curve. In addition, you can activate the revolutionary traction control at the push of a button. Bring it on, world.
- Triple Clamps: The new generation is fitted with forged triple clamps with an offset of 22mm, ensuring a solid grip of the fork and precise handling. You can move the handlebar forwards and backwards over 4 positions, so the bike should fit you like your gloves.
- Airbox: The revised airbox design, incorporating new snorkels, offers maximum protection of the air filter against soiling, while ensuring maximum airflow in a quiet way. The new, large Twin Air filter is mounted in a stiff cage, which at the same time holds the system in place. This design is so simple, you could still pop a fresh one in with a face full of mud. Without tools. In seconds.
- Fuel Tank: A lightweight polyethylene tank with a capacity of 8.5 liters of juice. You will always be able to see how much fuel there’s left at a glance, thanks to its see-through plastic. By pushing the orange release button in the center of the filler cap, the bayonet mechanism makes refueling a snap. The 4-stroke models are fitted with an integrated fuel pump system and an additional fuel level sensor. On the new models the fuel line features a 90° connector to the tank for better protection against damage.
- Exhaust: FIM noise limits are a real challenge for every manufacturer. Therefore, KTM has put a lot of effort into the development of their exhaust systems. All 4-strokes are fitted with new header pipes and a shorter silencer, mounted as close to the engine as possible. You know what that means: more power, extra mass centralization and better rideability. An advanced internal design reduces the noise sufficiently in order to sit safely below the FIM noise limit, while still raising the hairs on your neck.
- Wheels: The KTM wheels feature lightweight, CNC machined hubs and high-end Giant rims guaranteeing maximum stability at minimum weight. The wheels are fitted with the latest Maxxis tires. The rear tire features a reworked profile and internal structure for better grip under wet conditions and is more resilient to punctures. Take them wherever you like, traction will be waiting.
- Cooling System: KTM’s proven cooling system routes the coolant from the cylinder head through the frame triangle, directly to aluminum radiators made by WP, which have a new filler cap system and are made of a stiffer alloy. Due to flow optimized internal circulation and CFD-calculated air ventilation, the system is superbly efficient. In addition, well thought-out radiator guards integrated in the front part of the spoilers provide protection in case of crashes.
- Seat: Tailored to meet the needs of the world’s fastest backsides, this durable seat offers great comfort, while being 10mm lower to help you master the most challenging terrain.
- Battery & Wiring Harness: All EXC-F engines are fitted with an electric starter – a unique KTM feature and a major benefit at all levels of offroad racing. A super compact 495g lithium ion starter battery breathes life into the engine, shaving off an entire kilogram of excess weight while offering three times the starting energy. Because of its reliability, we decided to eliminate the kick-starter entirely. The battery and wiring harness are centralized in a compartment above the airbox, allowing the mechanic to remove the subframe without getting in conflict with the electrics. Because a happy mechanic, is a good mechanic.
- Bodywork: KTM R&D, Kiska Design and all our factory riders had their say in shaping the plastics. Their goal: complete harmony between rider and bike. And so it turned out. Perfect ergonomics and contact points, maximum freedom of movement, a low seat height and sweet comfort, especially in the rear part of the seat. The I-beam structures of the front and rear fenders are prime examples of such an intelligent design, guaranteeing maximum stability and a low weight thanks to well thought-out construction and mounting. Plus: they stay cleaner for longer. Or take a look at the headlight fairing. Can you spot the smart solution that makes sure your brake hose never makes nasty scratches again?
- Graphics: A new, tailor-made kit, fit for a king. Because in this sport, champs deserve to look the part regardless of the dirt.
- Design: 1-cylinder, 4-stroke engine
- Displacement: 249.91 cm³
- Bore: 78 mm
- Stroke: 52.3 mm
- Starter: Electric starter
- Transmission: 6-speed
- Primary drive: 24:73
- Secondary gear ratio: 14:49
- Clutch: Wet, DDS multi-disc clutch, Brembo hydraulics
- EMS: Keihin EMS
- Frame design: Chrome-molybdenum steel central-tube frame
- Rear suspension: WP Xplor PDS shock absorber
- Suspension travel (front): 300 mm
- Suspension travel (rear): 310 mm
- Front brake: Disc brake
- Rear brake: Disc brake
- Front brake disc diameter: 260 mm
- Rear brake disc diameter: 220 mm
- Steering head angle: 63.5 °
- Wheelbase: 1482 ± 10 mm
- Ground clearance: 355 mm
- Seat height: 960 mm
- Tank capacity (approx.): 8.5 l
- Weight READY TO RACE (without fuel): 107 kg
- Engine Type
- 1-cylinder, 4-stroke engine
- 249.91 cm³
- Bore and Stroke
- 78 x 52.3 mm
- Rear Suspension
- WP Xplor PDS shock absorber
- Front Brakes
- Disc brake
- Rear Brakes
- Disc brake
- 1482 ± 10 mm
- Seat Height
- 960 mm
- Fuel Capacity
- 8.5 L
- Dry Weight
- 107 kg