If maximum power is required, there is no other way but the 450 SX-F. This model has proven itself in the main championships around the world over the years. Thanks to its compact SOHC (single overhead camshaft) engine that delivers explosive but controllable power, it is the weapon of choice for the US KTM Factory Team and Ryan Dungey winning the AMA Supercross championship 2015.
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.
FORKS – (Europe Only) 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.
(USA – The KTM SX-F models feature the advanced WP 4CS four-chamber closed cartridge fork with an updated setting for 2016. The 4CS 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 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.
ENGINE – With new features such as its much more compact dimensions, stronger performance throughout the rev range and a weight reduction of 1.8 kg, this newly developed powerplant is the lightest 450 engine on the MX market. With a reworked single overhead camshaft cylinder head and the latest electronic fuel injection, it is distinguished by unrivalled power of more than 62 hp and a highly efficient power delivery.
CYLINDER HEAD – Inside the newly designed cylinder head with its reworked water jacket and combustion chamber, the gas flow through the optimized ports is controlled by an all-new overhead camshaft. This activates four ultra-lightweight titanium valves via extremely rigid rocker arms, which are DLC coated on the intake side. This configuration allows engine speeds of up to 11,500 rpm. In addition, the head is 350 g lighter than the previous model due to the compact design.
CYLINDER HEAD AND PISTON – In the reworked and 6 mm shorter cylinder, featuring an optimized water jacket and a bore of 95 mm, is an extremely lightweight box-in-box type piston together with a weight optimized piston pin that delivers a major contribution to the engine’s low vibrations and engine-speed strength. The compression ratio is 12.6:1.
ENGINE CASES AND COVERS – The completely new design of the die-cast engine cases allows for a much more centralized shaft configuration, raising the crankshaft by 7 mm and 9 mm backwards closer to the bikes center of gravity – a weight saving of 550 g and a weight reduction to 27.3 kg (EU), 27.8 kg (USA). Newly designed engine covers made of magnesium feature an advanced surface structure in order to reduce the wear caused by the rider’s boots.
TRANSMISSION – The new engine of the 450 SX-F uses a lightweight 4-speed gearbox with unchanged gear ratios that are perfectly matched to the power delivery of the large displacement engine. In addition the 1st and 3rd gears are now treated with a special surface treatment for better reliability. On the US market, the 450 SX-F is delivered with a 5-speed gearbox in order to meet the demands of the American customers using the bikes on faster tracks and for desert rides.
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.
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.
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.
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.
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.
1-cylinder, 4-stroke engine
Wet, DDS multi-disc clutch, Brembo hydraulics
25CrMo4 steel central-tube frame
WP-USD, AERforce, Ø 48 mm, US Models retain 4CS fork
WP monoshock with linkage
5/8 x 1/4″
1485 ± 10 mm