Take a look at the all new KTM 250 SX-F 2016 presented yesterday in Milan, Italy. Below is all the information about this magical little machine from KTM.
The 250 SX-F is once again the World Champion in MX2 and adds a prestigious AMA Supercross Lites Championship to its amazing trophy cabinet. The 2014 season was a great success in racing at all levels around the globe, and 2015 promises to be no different. Already known for its strong performance, the new generation 250 SX-F presents itself with a newly developed, stronger engine built into an all-new chassis. The performance combination of a powerful and much torqueier engine in a lightweight and agile chassis is sure to make the 250 SX-F the star of the show for the future. The new 250 SX-F, the lightest and best performing bike in its class, is the right choice for both the amateur and professional riders, as it will remain a winning bike that will be hard to chase for its competitors.
COMPACT AND LIGHT POWER PLANT
ENGINE
The new 250 SX-F engine is based on the similar overall design of its predecessor, with some major refinements to make this MX2 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 1.1 kg to a total of 26.1 kg, including the incredibly beneficial electric starter. The reworked power unit guarantees an improved power curve over the entire rev range up to 14,000 rpm, which makes the new 250 SX-F much easier to ride 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 timings, 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, which concludes at an engine speed “sound barrier” 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 ground 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 cm³ 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, which at the same time 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 again fitted with an electric starter as standard, which is well known as a clear advantage when it comes to crunch time 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. This and further developments make the engine shorter by 20 mm, while contributing to a much more centralized mass. Newly designed engine covers made of magnesium feature an advanced surface structure in order to reduce 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 guarantee a better oil supply along with even better cooling of the clutch. A smaller master cylinder diameter of the Brembo hydraulic clutch system provides easier and precise modulation.
TRANSMISSION
The new engine is fitted with an all-new and weight reduced, five-speed gearbox. It features the same gear ratio as the previous model, but has wider gear sprockets, featuring a special surface treatment on the 2nd, 3rd and 4th gears for improved reliability. 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 a spontaneous 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.
MASSIVE WEIGHT REDUCTION
AIRBOX
The new airbox design offers maximum protection of the air filter against soiling, while ensuring maximum airflow in conjunction with new and 300 g lighter intake snorkels that are made of a new material (reducing the deformation due to air intake pulses) for improved performance. As found on previous models, the new Twin Air filter is easier and safer to mount and can be changed without tools in seconds, a standard, original feature by KTM.
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 MY 2016 the SX-F range fits a super compact and lightweight 495 g lithium-ion starter battery into a standard motocross bike, providing safe starting of the engine and reducing the weight by 1 kg over MY 2015!
BRAKES
High-tech Brembo brakes have always been standard equipment on KTM offroad bikes, and are combined with newly designed and weight-reduced Wave discs made by GALFER featuring also an improved heat resistance. The ultimate solution in braking technology. Weight reduction front 63 g, rear 32 g.
SEAT
Ergonomically perfect, the new seat has a higher foam volume, which offers great comfort and durability at the same time, while weighing the same as the previous model.
NEWLY DESIGNED CHASSIS
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 around 380 g 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.
SWINGARM
As on the predecessor models, the new SX generation features a reworked cast aluminium swingarm. The updated design offers reduced weight and an optimized flex behavior supporting the frame and suspension created with a single-component casting process. The weight reduction is 250 grams.
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.
FUEL TANK
All models of the SX range have new lightweight polythene tanks with a capacity of 7.0 liters of petrol. The filler cap with an inside thread makes for an easy and reliable closure. The 4-stroke models are fitted with an integrated fuel pump system.
GRAPHICS
New modern in-mold graphics highlight the sporty character of the MY 2016 SX range of cutting-edge Motocross bikes.
COOLING SYSTEM
The proven integrated KTM cooling system routes the coolant from the cylinder head through the frame triangle, directly to newly developed aluminium 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 efficient protection in case of crashes.
HANDLEBAR
The new generation SX models are equipped with a new tapered handlebar made of high-strength aluminium by NEKEN, which is fixed in a new rubber damped handlebar clamp allowing the handlebar to be mounted in two different positions.
All 4-stroke models feature a new throttle assembly with exchangeable throttle cams for different opening characteristics and new ODI grips featuring lock-on fixing clamp on the left-hand side. In addition a map switch allows the selection of different maps and the activation of a launch control.
STATE-OF-THE-ART SUSPENSION
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, including the reworked linkage system and the new WP forks. The linkage system has also been reworked with a revised geometry and longer pull rods, which was tested last season in most of the KTM factory bikes.
FORKS
The KTM SX models are fitted with a revolutionary new and super-lightweight WP fork, a 48 mm USD air-sprung fork developed by WP Suspension in close collaboration with KTM. It is a split fork with separate functions for each fork leg. The damping functions are on the right side, whereas the air spring is in the left. The left leg features a capsuled air cartridge. This air spring is easy to adjust to any rider weight via a single air valve and a standard fork air pump. The right fork leg integrates a completely new damping cartridge to fit single damping leg requirements, and the damping can be adjusted to the track conditions or the rider’s preferences with a twist of a dial. The new fork with approximately 300 mm travel has outstanding response and excellent, very consistent damping characteristics, while also with a reduced weight of 1.4 kg compared to its predecessor.
TRIPLE CLAMP
Top quality, CNC-machined 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. For MY 16 the upper triple clamp features a newly developed rubber damping system for the handlebar clamp in order to reduce the vibration level of the handlebar. The clamps retain their forward and back adjustability for any rider preference.
WEIGHT REDUCTION
The main target for the KTM engineers when developing the new SX generation was a massive weight reduction in conjunction with an improved handling. The result of between 4 and 5 kg is outstanding making the new KTM models the lightest bikes in the competition, even though the 4-strokes are equipped with a super-beneficial electric starter as a standard feature, while the competitor models need to be kickstarted.
UNRIVALLED HANDLING
WHEELS
The 250 SX-F is fitted with lightweight, CNC-machined hubs, high-end Excel rims and new, weight reduced spokes with lightweight aluminium nipples providing maximum stability at minimum weight. The latest MX tires from Dunlop (Geomax MX 32) have been developed from KTM factory racing in the USA, factory testing and expert rider feedback in racing. They guarantee perfect traction and outstanding performance.
BRAKES
High-tech Brembo brakes have always been standard equipment on KTM offroad bikes, and are combined with newly designed and weight-reduced Wave discs made by GALFER featuring also an improved heat resistance. The ultimate solution in braking technology. Weight reduction front 63 g, rear 32 g.
ENGINE
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DESIGN
1-cylinder, 4-stroke engine
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DISPLACEMENT
249.9 cm³
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BORE
78 mm
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STROKE
52.3 mm
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STARTER
Electric starter
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TRANSMISSION
5-speed
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PRIMARY DRIVE
24:73
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SECONDARY GEAR RATIO
13:50
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CLUTCH
Wet, CSS multi-disc clutch, Brembo hydraulics
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EMS
Keihin EMS
CHASSIS
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FRAME DESIGN
25CrMo4 steel central-tube frame
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FRONT SUSPENSION
WP-USD, AERforce, Ø 48 mm
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REAR SUSPENSION
WP monoshock with linkage
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SUSPENSION TRAVEL (FRONT)
300 mm
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SUSPENSION TRAVEL (REAR)
300 mm
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FRONT BRAKE
Disc brake
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REAR BRAKE
Disc brake
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FRONT BRAKE DISC DIAMETER
260 mm
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REAR BRAKE DISC DIAMETER
220 mm
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CHAIN
5/8 x 1/4?
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STEERING HEAD ANGLE
63.9 °
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WHEELBASE
1485 ± 10 mm
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GROUND CLEARANCE
370 mm
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SEAT HEIGHT
960 mm
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TANK CAPACITY (APPROX.)
7 l
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WEIGHT READY TO RACE (WITHOUT FUEL)
98.5 kg