Motorcycle specifications KTM250 SX-F 2016 In pole for action

Already renowned for its power, the new-generation 250 SX-F features an even more powerful engine mounted on a completely new chassis. By combining a more powerful and torquey engine with a lightweight, easy-to-handle chassis, the new 250 SX-F is sure to be the star of tomorrow. The lightest and best-performing motorcycle in its class, the 2016 250 SX-F is destined to retain its champion status, making it the ideal choice for amateur and professional riders alike.

lighter weight

The main objective of KTM engineers when developing the new generation SX was to significantly reduce weight and improve handling. With a weight reduction of between 4 and 5 kg, the result is exceptional, making the new KTM models the lightest motorcycles on the market, despite the fact that the four-stroke models are fitted as standard with a highly beneficial electric starter, whereas competing models have to be kick-started.

fork

The new KTM SX models are equipped with a revolutionary new ultra-light WP fork, a 48 mm inverted air-sprung fork developed by WP Suspension in close collaboration with KTM. This is a split fork with separate functions for each fork arm. The damping functions are on the right, the air spring on the left. The left fork arm houses an air cartridge. The air spring is easily adjusted to the rider's weight using a single valve and a standard fork air pump. The right fork arm features a new cartridge specially designed to meet the requirements of the single-arm design, and damping can be adjusted to suit track conditions or rider preference with a simple turn of a knob. With a travel of around 300 mm, the new fork offers exceptional response and excellent, consistent damping characteristics. It is also 1.4 kg lighter than the previous model.

fork crown

High-quality CNC-machined fork crowns have been a KTM trademark for many years. Enabling precise steering, they significantly enhance the flexibility characteristics and, thus, the action of the fork. For 2016, the upper fork tee features a new rubber damping system for the handlebar clamp to reduce the level of handlebar vibration. The fork tees retain front-to-rear adjustability according to rider preference.

monoshock

The new generation of monoshocks manufactured by WP Suspension has been designed for the new SX models, in conjunction with the new frame and swingarm architecture, modified linkage and new WP fork. The linkage system has also been reworked, with modified geometry and extended tie-rods, and was tested last season on most KTM factory bikes.

engine
the 250 SX-F engine is based on the general design of its predecessor, but has received significant improvements to achieve a more compact and lightweight MX2 engine. Torque and power have been improved across the entire speed range. One of the most spectacular benefits of the new design is a weight saving of 1.1 kg, for a total of 26.1 kg including the highly beneficial electric starter. The new engine offers an improved power curve throughout the rev range up to 14,000 rpm, making the new 250 SX-F much easier to handle for amateur and professional riders alike.

cylinder head

The centerpiece of the compact DOHC (double overhead camshaft) engine is the new, state-of-the-art cylinder head. It features improved combustion chamber geometry, two 150g lighter overhead camshafts with new valve train and ultra-fine, friction-optimized surface, new cam followers with 30% harder DLC coating, and improved valve train drive (reduced friction and shorter DID timing chain, new chain guides and sprockets). New valve springs and cups for the four ultra-light titanium valves (intake 32.5 mm, exhaust 26.5 mm) and high-flow ports maximize flow for optimum rpm range and maximum performance up to the engine speed limit of 14,000 rpm.

cylinder and piston

The improved, shortened cylinder, with a 78 mm bore, houses a forged, box-type piston, reinforced and lightened by CP. The piston's unique shape is adapted to the new combustion chamber, and features a highly rigid structure and reduced weight. Compression is 14.4:1. Reduced oscillating masses give the engine an extremely responsive character.

crankshaft

The crankshaft of the new 250 SX-F offers greater rigidity and uses a 6 mm shorter connecting rod, contributing to the engine's responsive character. The connecting-rod bearing features two force-fitted half-bearings acting directly on the crankpin. This design is the prerequisite for extremely high speeds and unrivalled power from the 250 cm³ engine. It also improves engine longevity, enabling longer crankshaft overhaul intervals.

balancer shaft

To balance mass forces, the new 250 SX-F engine uses a multifunctional balancer shaft that simultaneously drives the water pump and timing chain. It is fitted with new sprockets mounted on the new timing chain.

electric starter

The new 250 SX-F is once again fitted as standard with an electric starter, a decisive advantage for reducing lap times in competition. The new Mitsuba electric starter (modified for easier disassembly) and lightened drive system improve starting efficiency and reliability.

crankcase and cover

The entirely new design of molded engine housings offers a much more centralized shaft configuration. With a number of additional developments, it has made it possible to shorten the engine by 20 mm and achieve a much more centralized weight distribution. The new magnesium engine covers feature an advanced surface structure to reduce wear caused by the rider's boots.

engine management system

The completely redesigned Keihin electronic fuel injection engine management system features a new 44 mm throttle body for spontaneous response and maximum performance, thanks to a revolutionary injector position. The new ECU (Engine Control Unit) includes a start-up control function to improve starting efficiency, and provides different configurations depending on which gear switch is selected. Using the handlebar-mounted selector, the rider can also activate an optional configuration for a different power curve.

clutch

The new compact CSS (Coil Spring Steel) clutch features a lightened, wear-free steel bell, and 7 (instead of 8) clutch plates with high heat resistance thanks to their steel support plates. Improved internal hub and pressure plate ensure better oil supply and clutch cooling. The smaller master cylinder diameter of Brembo's hydraulic clutch system makes modulation easier and more precise.

gearbox

The new engine is equipped with an all-new, lightweight 5-speed gearbox. It offers the same ratios as the previous model, but features wider gears with specially treated surfaces for 2nd, 3rd and 4th gears, improving reliability. A special new feature is the "zero dirt" design of the gearshift lever, which prevents dirt from blocking the lever joint, guaranteeing safe operation of the gearbox.

air box

The new airbox design offers optimum protection of the air filter against clogging and maximum airflow. The new intake snorkels are 300g lighter and made from a new, performance-enhancing material that reduces deformation caused by air intake pulses. As on previous models, the new double air filter is easy and safe to fit, and can be changed in seconds without tools - an original KTM standard feature.

battery and wiring harness

As in the past, all SX-F engines feature the proven electric starter - a KTM exclusive and a major advantage in motocross competition. For 2016, the SX-F range has succeeded in integrating an ultra-light and compact lithium-ion starter battery weighing 495 g on a standard motocross bike, enabling safe starting and a weight saving of 1 kg compared to 2015!

brakes

High-tech Brembo brakes have always been standard equipment on KTM off-road bikes. They are combined with redesigned, lightened wave-type discs with improved thermal resistance manufactured by GALFER. The ultimate solution in braking technology. 63g lighter at the front, 32g lighter at the rear.

wheels

The 250 SX-F features ultra-light CNC-machined hubs, top-of-the-range Excel rims, new lightened spokes and aluminum spoke-heads for maximum stability and minimum weight. Dunlop's new MX tires (Geomax MX 32) have been developed with the KTM racing team in the USA on the basis of factory tests and the racing experience of seasoned riders. They guarantee perfect traction and exceptional performance.

frame

The new frame design offers around 20% more torsional stiffness, around 30% less longitudinal stiffness, and features redesigned engine mounting lugs to reduce vibration. This increased flexibility enables better absorption of the energy generated by front and rear wheel loads, supporting the suspension for greater comfort and reduced rider fatigue. A 0.4° greater steering angle and a 10 mm shorter wheelbase contribute to improved handling, as does a 380 g lighter weight than the previous model.

footrests

A new "zero-dirt" footrest design prevents dirt from blocking the footrests when they are returned to position, even in deep ruts. The new footrests are also wider and more stable, offer better grip and are lighter than on previous models.

swingarm

As on previous models, the new generation SX is equipped with a new cast aluminum swingarm. The new one-piece cast swingarm offers reduced weight and optimized bending behavior for enhanced damping characteristics. The weight saving is 250 g.

cladding

For the new generation of SX models, KTM factory riders collaborated with KTM R&D specialists and Kiska Design to design the bodywork. The aim was to achieve perfect harmony between rider and bike, right down to the smallest detail. The result: new plastics offering perfect ergonomics and contact points for the rider, maximum freedom of movement, a saddle lowered by 10 to 20 mm (at the rear) and improved comfort, particularly at the rear of the saddle.

fuel tank

All SX models feature a new, ultra-light 7-liter polyethylene fuel tank. The internally threaded tank cap ensures easy, reliable closure. Four-stroke models feature an integrated fuel pump system.

graphics

New, modern IML graphics underline the sporty character of the top motocross bikes in the 2016 SX range.

handlebars

The new SX generation models feature a new NEKEN tapered handlebar in high-strength aluminum, mounted on a new clamp equipped with a shock-absorbing gasket and offering two handlebar mounting positions.
All four-stroke models feature a new butterfly assembly with interchangeable cams for different opening characteristics, and new ODI grips with lockable clamp on the left side. A selector allows different configurations to be selected and a start-up control function to be activated.

saddle

Perfectly ergonomic, the new saddle offers superior foam plastic volume, ensuring comfort and durability for the same weight as the previous model.

cooling system

The integrated KTM cooling system channels coolant from the cylinder head through the frame triangle to the new aluminum WP radiators, equipped with a new plug system and made of a stiffer alloy. Thanks to optimized internal circulation and ventilation calculated by CFD simulation, cooling efficiency has been improved by around 10%. Elaborate radiator guards provide effective protection in the event of an accident.

News and media credits: KTM