2017 KTM SX - 250 F
Pro Caliber Bend
SX - 250 F
- Engine: The new 250 SX-F engine is based on the similar overall design of its predecessor, with some major refinements to make this power plant more compact and lighter, with the production of improved torque and power across the entire rpm range. Perhaps one of the most impressive benefits of the new design is a weight reduction of 2 lbs, while still including the incredibly beneficial electric starter. The reworked engine guarantees an improved power curve over the entire rev range up to 14,000 rpm, which makes the new 250 SX-F a winner for both amateur and professional riders.
- Cylinder head: 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.
- Cylinder & piston: In the reworked and shorter cylinder that has a bore of 78 mm, is a weight-reduced, forged bridged box-type piston made by CP. It features a unique piston shape adapted to the new combustion chamber and stands out with its extra-rigid structure, combined with a low weight. The compression ratio is at 14.4:1. Thanks to the low oscillating masses, the engine offers extremely lively characteristics.
- Crankshaft: The new 250 SX-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 cc engine. Not only that, it enhances the engine's durability, allowing long crankshaft service intervals.
- Counter balancer shaft: In order to balance the mass-forces, the new 250 SX-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.
- Electric starter: The new 250 SX-F is fitted with an electric starter as standard, which 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.
- Engine cases and cover: 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.
- Clutch: 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.
- Airbox: The new airbox design offers maximum protection of the air filter against soiling, while ensuring maximum airflow in conjunction with lighter intake snorkel that is made of a new material to reduce the deformation due to air intake pulse for improved performance. The new Twin Air filter is easier and safer to mount and can be changed without tools in seconds - a standard and original KTM feature.
- Battery and wiring harness: As in the past, all new SX-F engines are fitted with the proven electric starter - a unique KTM feature and a major benefit at all levels of motocross racing. For 2016 the SX-F range fits a super compact and lightweight 1.1 lb lithium-ion starter battery into a standard motocross bike, providing safe starting of the engine and reducing the weight by 2.2 lbs over the 2015 model!
- Seat: Ergonomically perfect, the new seat has a higher foam volume, which offers great comfort and durability, while weighing the same as the previous model.
- Frame: The new frame design provides approximately 20 % higher torsional rigidity and 30 % less longitudinal stiffness, with newly designed engine stays for less vibration. This increased flexibility results in better absorption of the energy created from the front and rear wheel loads supporting the suspension for more comfort and less rider fatigue. A 0.4° steeper steering angle and a 10 mm shorter wheel base contribute to better handling, and last but not least it´s lighter than the previous model.
- Footpeg: A new sophisticated "No-Dirt" footpeg solution prevents dirt from blocking the pegs and stopping them from returning to the proper position, even when digging in deep ruts. In addition the new footpegs are larger, more stable, lighter than on previous models and offer more grip.
- Bodywork: For the new generation of SX models the KTM factory riders were involved in shaping the bodywork together with the specialists from KTM R&D and Kiska Design. The goal was to achieve complete harmony between rider and bike down to the finest details. The results are all-new plastics that provide perfect ergonomics and contact points for the rider, maximum freedom of movement, a lower seat height of between 10 to 20 mm (rear end) and better comfort, especially in the rear part of the seat.
- Swingarm: The new SX generation features a reworked cast aluminum swingarm. The updated design offers reduced weight and an optimized flex behavior created with a single-component casting process. The weight reduction is 250 grams.
- Graphics: Troy Lee Designs gives this Factory Edition a head start, even when you’re standing still.
- Fuel tank: All models of the SX range have new lightweight polythene tanks with a capacity of 1.85 gallons and an integrated fuel pump. A filler cap with an inside thread makes for an easy and reliable closure.
- Cooling system: The proven integrated KTM cooling system routes the coolant from the cylinder head through the frame triangle, directly to newly developed 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 cooling efficiency has been improved by approximately 10% and the sophisticated radiator guards provide protection in case of a crash.
- Handlebar: Orange anodized CNC-machined triple clamps feature a rubber damping system, Neken handlebar and ODI lock-on grips. These triple clamps have been something of a KTM trademark for years. Ensuring a precise handling, they perceptibly support the flex characteristics, and with it, the action of the forks. The newly developed rubber damping system for the handlebar clamp reduce the vibration level. Of course the clamps retain their forward and back adjustability for any rider preference.?
- Monoshock: The new generation of monoshock made by WP Suspension has been developed for the new SX models in conjunction with the new frame and swingarm architecture that includes a reworked linkage system and new WP forks. The linkage system has a revised geometry and longer pull rods, which was tested last season in the KTM factory bikes.
- Fork: The KTM SX-F models feature the advanced WP AER 48 fork with an updated setting for 2016. The fork has been specifically designed and adapted for motocross racing in the USA.
- Triple clamp: Top quality, CNC-machined triple clamps have been something of a KTM trademark for years. Ensuring precise handling, they provide proper clamping force for correct flex characteristics, thus improving the action of the forks. For 2016 the upper triple clamp features a newly developed rubber damping system for the handlebar clamp in order to reduce the vibration levels felt through the handlebar. The clamps retain their forward and back adjustability for rider preference.
- Weight reduction: The main target for the KTM engineers when developing the new SX-F generation was a massive weight reduction in conjunction with improved handling. The resulting loss of 5.1 lbs is outstanding, making the new KTM models the lightest bikes on the track.
- Wheels: The 250 SX-F is fitted with lightweight, CNC-machined hubs, high-end D.I.D. rims and new, weight reduced spokes with lightweight aluminum nipples providing maximum stability at minimum weight. The latest Dunlop Geomax MX32 tires have been developed with KTM factory racing in the USA and expert test riders. They guarantee perfect traction and outstanding performance.
- Brakes: High-tech Brembo brakes have always been standard equipment on KTM off-road bikes, and now are combined with newly designed and weight-reduced Wave discs made by GALFER featuring improved heat resistance. Weight reduction is 63g on the front disc, and 32 g for the rear. This is the ultimate solution in braking technology.
- Design: 1-cylinder, 4-stroke engine
- Displacement: 249.9 cm³
- Bore: 78 mm
- Stroke: 52.3 mm
- Starter: Electric starter
- Transmission: 5-speed
- Primary drive: 24:73
- Secondary gear ratio: 13:50
- Clutch: Wet, CSS multi-dISC clutch, Brembo hydraulics
- EMS: Keihin EMS
- Frame design: 25CrMo4 steel central-tube frame
- Front suspension: WP-USD, AER 48, Ø 48 mm
- Rear suspension: WP shock absorber with linkage
- Suspension travel (front): 300 mm
- Suspension travel (rear): 300 mm
- Front brake: DISC brake
- Rear brake: DISC brake
- Front brake dISC diameter: 260 mm
- Rear brake dISC diameter: 220 mm
- Chain: 5/8 x 1/4 in.
- Steering head angle: 63.9 deg.
- Wheelb.ase: 1485 mm
- Ground clearance: 370 mm
- Seat height: 960 mm
- Tank capacity (approx.): 7 l
- Weight READY TO RACE (without fuel): 98.5 kg
- Engine Type
- 1-cylinder, 4-stroke engine
- 249.9 cm³
- Bore and Stroke
- 78 mm x 52.3 mm
- Front Suspension
- WP-USD, AER 48, Ø 48 mm
- Front Brakes
- Disc brake
- Rear Suspension
- WP shock absorber with linkage
- Rear Brakes
- Disc brake
- Dry Weight
- 98.5 kg
- Fuel Capacity
- 7 L
- 1485 ± 10 mm
- Ground Clearance
- 370 mm
- Seat Height
- 960 mm