Motorcycle specifications KTM450 SX-F 2020 Power as a guide

The KTM 450 SX-F has proven itself over the years in the world's leading championships. The 2020 model takes performance and handling to new heights. It features an ultra-compact single overhead camshaft cylinder head and a high-performance electronic fuel injection system. Powered by a 63 HP engine of rare efficiency, the 450 SX-F is undoubtedly one of the fastest motocross bikes on the circuit.

engine and silencer

4-stroke engines have revolutionized motocross and established KTM as a major player in the sport. Incredibly light and compact, these little engineering gems impress with their power and dynamism. just out of the dealership, KTM 4-strokes let you experience the highest level.

engine

the 450 cm3 engine is the most competitive in the KTM motocross range. It features a single overhead camshaft cylinder head fed by the latest electronic fuel injection system. As a result, the impressive 63 hp of power is distributed more efficiently across the rev range. Even with the highly beneficial electric starter, this model remains the lightest 450 cm3 on the motocross market.

cylinder head

the 450 SX-F features a compact, lightweight SOHC (single overhead camshaft) cylinder head. The emphasis is on mass centralization for greater agility. The overhead camshaft has a surface designed to minimize friction. The valve train has been designed to improve engine responsiveness. The four ultra-light titanium valves (intake: 40 mm, exhaust: 33 mm) are operated by ultra-rigid rockers. The rockers are DLC-coated on the intake side to enable extremely high engine speeds of up to 11,500 rpm. Low-friction chain guides support these high speeds. The innovative overhead shaft configuration ensures unrivalled power delivery to leave the competition in its wake.

crankshaft

the 450 SX-F's crankshaft is ideally positioned, close to the center of gravity, to better centralize mass. It uses a short connecting rod, making the engine even more compact and responsive. The whole unit is perfectly balanced. Inertia forces are ideally balanced to enhance traction and driving pleasure. The connecting-rod bearing features two half-bearings force-fitted directly onto the crankshaft crankpin, and the oil supply is provided by the engine's pressure lubrication system. This design extends engine life and extends crankshaft service intervals, saving the customer time, effort and money.

crankcases and covers

the use of a high-pressure die-casting process results in a relatively compact crankcase that is even lighter, while maintaining its strength and durability. The design of the crankcase has enabled KTM engineers to move the shaft mountings closer to the center of gravity, so as to better centralize the masses and enhance rideability. Another interesting innovation to keep the engine as radiant as in the early days: crankcase covers with an elaborate surface structure, designed to reduce wear caused by the rider's boots.

gearbox

the 450 SX-F's gearbox focuses on performance and lightness, without compromising durability. The ratios, perfectly matched to the power delivered by the large-displacement engine, have not changed. The secondary gear ratio (sprockets) is shorter (13/49) for maximum acceleration. All 4-stroke engines are equipped with an engaged-gear sensor, which adapts engine characteristics to each gear, depending on engine load. The "zero dirt" design of the selector prevents the accumulation of mud or dust at the joint. And because the new gearbox is so reliable, shifting gears has never been easier.

engine management

the highly sophisticated Keihin engine management system, with electronic fuel injection, features a 44 mm injector body. The position of the injector ensures excellent atomization of the fuel and air entering the combustion chamber. The engine is even more lively and generous when the throttle is opened. You also have independent control systems for cold start and idle. The engine control unit (ECU) offers specially adapted exhaust and cylinder head mappings to better manage traction and start-up control. To deliver maximum power, the ECU adapts the engine's characteristics to each gear, according to the data communicated by the gear sensor.

cylinder and piston

the 95 mm-bore cylinder houses a redesigned lightweight piston that meets the most stringent quality requirements. The piston, manufactured by CP, is extremely reliable. The cylinder's design helps to reduce vibration and increase overall engine performance. Reduced oscillating masses result in an engine that is both powerful and extremely responsive.

balancer shaft

the side-mounted balancer shaft performs a dual function, perfectly compensating for oscillating masses and simultaneously driving the water pump. Free from annoying vibrations, the bike offers unrivalled riding smoothness, even at high revs.

clutch

the 450 SX-F features a heavy-duty DDS (Damped Diaphragm Steel) clutch developed by KTM. This features a wear-free steel clutch housing and heat-resistant clutch plates. The use of a diaphragm spring instead of the usual coil springs makes it even more flexible. The diaphragm spring also has the advantage of being compact, enabling a damping system to be integrated into the clutch hub, for improved driveability and durability. The Brembo hydraulic clutch system is also distinguished by its precision and progressiveness.

electric starter

the electric starter, standard on the 450 SX-F, uses a proven drive system and Mitsuba's robust electric motor. This system has proven its worth time and again: its rock-solid reliability saves precious time and effort at crucial moments.

handlebar-mounted map selector

all 4-stroke models feature a handlebar-mounted map selector.all four-stroke models feature a handlebar-mounted map selector for traction and start control, and for switching between power curves (Standard Advanced). Traction control is designed to enhance traction and control during acceleration, especially on demanding tracks. This function can be activated, even at full throttle, by means of the map selector on the handlebars. When the engine is idling, simply press both switches at the same time to activate Start Control, and you'll be off the grid even faster. In addition to the standard engine modes, the map selector gives access to other engine modes for maximum racing options.

cooling

to ensure smooth power delivery, it's essential to maintain optimum engine temperature. The position of the 450 SX-F's radiators, perfectly matched to the design of the spoilers, lowers the center of gravity and enhances ergonomics. Thanks to CFD (Computational Fluid Dynamics) and a judicious cooling circuit, this innovative system ensures that engine components are kept at the ideal temperature to guarantee the highest level of performance, whatever the conditions. Special radiator guards not only protect the radiators from stones and other debris, but also distribute the force of impact around them.

muffler

the exhaust system, fitted to all 4-stroke models, gives the engine a smoothness and liveliness that are hard to match. It features an exhaust manifold (specific to each model) and a small additional chamber, i.e. an advanced resonator known as the FDH (Flow Design Header) or flow-design exhaust manifold. This design allows the exhaust to be disassembled without removing the shock absorber, and facilitates access to the latter. The aluminum sleeve, the muffler tip and the internal structure of the muffler offer a further ergonomic advantage, slimming the silhouette of the motorcycle while complying with regulatory noise emission levels.

chassis

the 450 SX-F delivers titanic torque and requires a frame of great strength to support the engine's prodigious power. The 2019 model year featured a new high-tech steel frame, light and well thought-out. This winning formula has been continued for the 2020 vintage. Its great flexibility means it can take the biggest knocks without flinching, and enhances the bike's agility and stability at high speeds. The chassis has also benefited from a number of innovations, such as "zero dirt" footrests and optional composite skid plate mounting brackets. Suspension damping characteristics have been optimized on the 2020 version. In particular, suspension settings have been revised to provide even greater flexibility and comfort. Combined with a high-performance, dynamic chassis, these suspensions make the driving experience more intuitive and enjoyable than ever.

frame

as with the rest of the KTM SX range, the frame of the KTM 450 SX-F is made of hydroformed chrome-molybdenum steel tubing.chromium-molybdenum steel, assembled by automated welding to guarantee the highest levels of quality. Rigidity has been designed to enhance handling. The excellent cohesion with the suspension offers the perfect compromise between agility and high-speed stability. The frame of all KTM SX 2020 models benefits from a highly resistant lacquered coating and standard frame protectors. The lightweight aluminum rear buckle provides excellent feel for the rider and promotes mobility in the saddle.

swingarm

the 450 SX-F's one-piece, high-pressure-molded swingarm has been designed for maximum strength and minimum weight. It offers a wide range of rear-wheel adjustments, allowing you to shorten the wheelbase for greater manoeuvrability on narrow, winding trails, or increase it for greater stability on fast sections. The chain measurement marks on the swingarm are visible from above, making adjustments much easier.

wheels

featuring ultra-light CNC-machined hubs and top-of-the-range Excel rims, the wheels on all SX models guarantee maximum stability despite limited weight. The aluminum spoke nipples have been redesigned to reduce the frequency with which spokes need to be re-tensioned. The wheels are fitted with latest-generation DUNLOP Geomax MX 3S tires, to maximize power transfer to the ground and enhance stability.

front suspension

all standard-size KTM SX models feature the ultra-light WP XACT AER fork, with new settings for the 2020 model year. The arms of this 48 mm USD air fork have different functions: damping is on the right, air springing is on the left. The left fork arm features a double-chamber air cartridge system designed to prevent any loss of pressure. Should the outer seal leak, the pressure exerted inside the inner cartridge will keep the bike in its normal position. The air spring is extremely easy to adjust, and can be adapted to the rider's weight using a single valve and the air pump supplied with the bike. The right fork arm features a cartridge specially designed to meet the requirements of the single-arm design, and can be adjusted to suit track conditions or rider preference. To fine-tune each of these settings (compression from the top and rebound from the bottom), simply turn the new 30-notch knob above each fork arm.

rear suspension

the WP XACT DDC shock absorber, featured on all KTM SX models, has beenthe WP XACT DDC shock absorber, found on all KTM SX models, was developed with the frame and swingarm architecture in mind, as were the linkage system and the WP XACT AER fork. Beyond its purely functional aspect, this little jewel captivates with its meticulous attention to detail, and in particular its high-quality machined and anodized components. Fully adjustable for high-speed and low-speed compression, it can be specifically adapted to track conditions or rider preferences.

fork tees

all KTM SX models use high-quality CNC-machined fork crowns, a KTM trademark. To take account of the flexibility of the frame and fork, engineers have stiffened the upper fork crown (22 mm offset on all models). The front end works in perfect harmony with the frame, making the bike even more stable and agile. Two positions are possible for the handlebar trigger guard, with vibration-damping pads. The hour meter, fitted as standard on the upper fork crown of all SX models, keeps track of hours spent in the saddle and indicates when it's time for maintenance.

brakes

state-of-the-art Brembo brakes are standard equipment on KTM motocross bikes. Combined with Wave brake discs renowned for their lightness, they deliver the stopping power expected by the most daring riders.

fuel tank

all KTM SX models feature an ultra-light polyethylene fuel tank. The shape of this tank has been designed to be more ergonomic, while retaining the same capacity (7 liters). The internally threaded fuel filler cap ensures easy, reliable closure.

air filter housing

the air filter housing on the KTM 450 SX-F optimizes flow dynamics. Combined with the intake snorkels, it ensures maximum power delivery and excellent acceleration. In addition to the obvious performance gains, the design also protects the air filter from clogging. The rigid support for the large Twin-Air filter has been designed to minimize installation errors. As with previous models, the filter can be serviced in record time and without tools, a typically KTM feature. (For U.S.A. only) Every KTM SX-F comes with a KTM PowerParts air filter housing cover. This features additional air inlets to optimize engine performance. In other words, it's possible to customize the air filter box to suit engine characteristics or track conditions.

ergonomics and comfort

to exploit the full potential of the SX range engine, the rider needs to be able to shift quickly and easily on the bike to compensate for forces in the opposite direction. In order to offer flawless ergonomics and guarantee optimum levels of performance and control, KTM engineers have ensured that the rider can adopt an ideal posture on the bike. As the rider interacts primarily with the fairing, seat, footrests and handlebars, all these contact points play a key role in balance and control. To tame the power of the KTM 450 SX-F and have total confidence in his mount, the rider must be able to rely on flawless ergonomics.

saddle

the saddle on all KTM SX models confirms the progress made in terms of dynamism and ergonomics. The saddle cover incorporates silicone strips to optimize grip and feel. A long screw inserted into the side of the saddle secures it more securely to the motorcycle, making it easier and safer to handle.

handlebars

all standard-size KTM SX models feature the same ultra-strong, profiled aluminum handlebars made by NEKEN. Two positions are possible for the handlebar trigger guard with shock absorbers. right: an ODI vulcanized grip available as standard; left: an ODI lock-on grip that's as comfortable as it is practical, thanks to its glue- and wire-free mounting system.

footrests

sophisticated "zero-dirt" footrests prevent the pivot from fouling, even when driving through deep ruts.

styling and graphics

taking to the track on a 450 SX-F sends out a strong signal to competitors. KTM factory riders collaborated on the development of the fairings for the entire SX range, with one watchword in mind: finding the perfect harmony between rider and machine. Careful attention to contact points was crucial to ensure maximum freedom of movement for the rider and enhanced handling. This bike is a clever cocktail of raw power and lightness, as evidenced by the particular shape of the front and rear hulls, designed to guarantee maximum stability without adding extra weight.

software and electronics

although the 450 SX-F's engine develops a demonic 63 hp, it remains entirely controllable. In addition to the mechanical elements designed to channel this energy, the rider can rely on an electronic package to dose it with maximum precision. The cartography selector on the handlebars can be used to adjust traction and start control, and to select different power curves. Many hours of work went into optimizing power and torque. Transferring this energy to the ground, however, requires state-of-the-art electronics. Operated at the touch of a button, the tried-and-tested electric starter is ready for any motocross eventuality.

battery

to start the engine every time, especially in cold weather, the starter on SX-F models is powered by an ultra-light, high-performance 2 Ah lithium-ion battery. The voltage regulator and capacitor, as well as all electrical components, are housed under the saddle for maximum reliability and compactness.

traction control

this extremely practical function ensures more efficient traction and better control of the bike during acceleration on wet or slippery surfaces. It can be activated, even in full throttle, by means of the map selector on the handlebars.

control at the start

simply press both map selector switches at the same time to activate START CONTROL and accelerate off the starting grid. Start Control reduces the engine's maximum speed at the precise moment of take-off, so you can maintain better control of your machine. The EFI light mounted on the upper fork tees flashes when this function is active.

handlebar-mounted map selector

at the touch of a button, the map selector switches between a standard engine mode and a more aggressive engine mode for trails with good grip. This allows the rider to better adapt the bike's handling to track conditions, or to benefit from better control when starting to show signs of fatigue.

Information and images credits: KTM