When it comes to the highly competitive battlefield of 250 cc offroad racing, the new generation KTM 250 XC-F is the general. Boasting a refined engine management system, the strongest 250 cc 4-stroke motor in pit lane and a reworked, race-bred chassis setup, the 250 XC-F is an education in speed and agility.
The centerpiece of the compact DOHC (Double Overhead Camshaft) engine is the new cutting-edge cylinder head. It features improved combustion chamber geometry, two 150 g lighter overhead camshafts with new timing, plus a friction-optimized super-fine surface, new finger followers with a 30 % harder DLC coating and a reworked timing drive (friction reduced and shorter DID timing chain, new sprockets and chain guides). New valve springs and retainers for the four lightweight titanium valves (intake 32.5 mm, exhaust 26.5 mm) and high-flow ports create a maximized flow rate for an optimal power band and maximum performance, all the way up to a redline of 14,000 rpm.
The new 250 XC-F's crankshaft features a stiffer design and employs a 6 mm shorter connecting rod, contributing to the compact and light engine with a snappy power delivery. A plain big end bearing features two force-fitted bearing shells run directly on the crank pin. This design is a major prerequisite for the extremely high engine speed levels and the unrivalled maximum power of the 250 cmÂ³ engine. Not only that, it enhances the engine's durability, allowing long crankshaft service intervals.
CRANKCASES AND ENGINE COVERS
The completely new design of the die-cast engine cases allowed for a much more centralized shaft configuration. The engine is now shorter by 20 mm, contributing to a much more centralized mass. Newly designed engine covers made of magnesium feature an advanced surface structure reducing the wear caused by the rider's boots.
KTM's proven cooling system routes the coolant from the cylinder head through the frame triangle, directly to aluminum radiators made by WP. Thanks to flow optimized internal circulation and CFD-calculated ventilation, the system is superbly efficient. In addition, new radiator protections improve heat dissipation. Especially in the mud. They are also integrated into the front part of the shrouds to protect the radiators in a crash.
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 aluminum engine head stays (the connection between cylinder head and frame) contribute to more precise cornering and a reduced vibration level. The engineers were able to pull off all that, while making their frame 2.2 pounds 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 aluminum, which tips the scales at less than 2 pounds.
The cast aluminum design offers low weight and a perfect flex behavior. The single-component casting process eliminates any inconsistencies and inherent weak points created by welding. Itâ€™s better looking too.
The 250 XC-F is fitted with lightweight, CNC-machined hubs, high-end Giant rims and black spokes with lightweight aluminum nipples providing maximum stability at minimum weight. The latest Dunlop Geomax AT81 tires guarantee perfect traction and outstanding performance.
The lightweight WP AER 48 front fork, a 48mm USD air-sprung fork developed by WP in close collaboration with KTM, is a split fork with separate functions for each leg. That means damping functions are on the right side, whereas the air spring is in the left. This left leg features a 2-chamber system with a capsuled air cartridge to prevent loss of air pressure. Should the outer seal start to leak, the internal cartridge pressure will keep the bike in position. The air spring is easy to adjust to any rider weight via a single air valve. No extra special tools are required; the fork air pump is supplied with the bike. The right fork leg integrates a damping cartridge that tailors to all your damping needs. It can be adjusted to the track conditions and the riderâ€™s preferences with a twist of a dial (compression from the top, rebound from the bottom, 30 clicks each). Right off the dealer floor, this fork (with reworked damping characteristics) is more comfortable and more sensitive than ever. But you can still hammer the hell out of it.
The WP shock absorber has been developed with the entire frame and swingarm architecture in mind, including the linkage system and the WP AER 48 front forks. It features machined and black anodized components and is a valuable, high-end product compared to roughcast reservoirs. A new, confidence inspiring setting with improved damping characteristics perfectly matches the front-end set-up and its WP color scheme lets everyone know you have excellent taste in suspension.
These high-tech Brembo babies are combined with lightweight Wave brake discs. You couldnâ€™t brake any harder, better, faster or stronger.
All XC-F models have new lightweight polyethylene tanks fitted with an integrated fuel pump system and capacity of 2.25 gallons. Inside threads on the filler cap make for an easy and reliable closure.
The air filter box design offers maximum protection of the air filter against soiling, while ensuring maximum airflow. The 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.
KTM engineers sure know how to handle handlebars. This tapered one, made of high-strength aluminum, is fixed in damped rubber mounts and has two different positions. ODI lock-on grips make grip changes easy and do not require any wire or glue to be secured.
Sophisticated 'No Dirt' footpegs prevent clogging of the footpeg pivot, even when digging in deep ruts. Looking for a higher riding position? Then just mount the footpegs of the 2018 EXC models, which are 6mm higher than the SX versions.
Ergonomically perfect, the seat has a high foam volume, which offers great comfort and durability, while keeping the weight low.
A new, tailor-made kit and a Factory orange frame. Because in this sport, champs deserve to look the part regardless of the dirt.
BATTERY & WIRING HARNESS
A strong new lithium ion battery breathes life into the engine and contributes to low vehicle weight. The lightweight battery and wiring harness are centralized in a compartment above the air filter box, allowing the mechanic to remove the subframe without moving the electronics. A happy mechanic is a good mechanic.
The new engine is fitted with an all-new and weight reduced, six-speed semi-close ratio gearbox. One of the new and special features on the bike is an advanced "NO-DIRT" gear lever design, which prevents dirt from blocking the joint of the lever and guarantees a safe activation of the transmission.
ENGINE MANAGEMENT SYSTEM
The completely reworked Keihin Engine Management System with electronic fuel injection features an all-new 44 mm throttle body, which provides instantaneous response and maximum performance thanks to a revolutionary injector position. The new ECU (Engine Control Unit) includes a launch control for more efficient starts with the provision of different maps according to the gear sensor selection. In addition, the rider can activate an optional map for a different power delivery via the map select switch on the handlebar.
CYLINDER AND PISTON
Inside the short cylinder, with a bore of 78mm, thumps a box-type piston made by CP. Its crown geometry is adapted perfectly to the high-compression combustion chamber, where its rigid structure and low weight shine. Thanks to the low oscillating masses, the engine is as snappy as it is strong.
In order to balance the mass-forces, the new 250 XC-F engine uses a multifunctional counter balance shaft that also drives the water pump and timing chain. It features new sprockets fitted to the new timing chain.
The highly compact CSS clutch (Coil Spring Steel) features a weight reduced, wear-free steel basket, and now seven instead of eight clutch plates, which are extremely heat resistant due to their steel carrier discs. In addition, a reworked inner hub and a pressure plate guarantees a better oil supply along with even better cooling of the clutch. A smaller master cylinder diameter of the Brembo hydraulic clutch system provides lighter pull and precise modulation.
The new 250 XC-F is fitted with an electric starter as standard, which is a clear advantage in the heat of battle. A new starter motor made by Mitsuba (modified for easy disassembly) and a weight-reduced starter drive guarantees more efficient and reliable starting.
1-cylinder, 4-stroke engine
Wet, DDS multi-disc clutch, Brembo hydraulics
25CrMo4 steel central-tube frame
WP-USD, AER 48, ø 48 mm
WP shock absorber with linkage
Suspension Travel (Front)
Suspension Travel (Rear)
Front Brake Disc Diameter
Rear Brake Disc Diameter
5/8 x 1/4"
Steering Head Angle
Tank Capacity (Approx.)
Weight Ready To Race (Without Fuel)