2019 KTM 450 SX-F
Power Supremacy: The championship winning KTM 450 SX-F is a proven formula that is the industry benchmark. For 2019, this new machine takes the next step in efficient performance and easy handling. It is fitted with a newly designed, extremely compact, single overhead camshaft cylinder head, as well as the latest electronic fuel injection. Pushing out an unrivalled 63hp in the most effective way possible, this 450 cc is the fastest Motocross bike KTM has ever built.
- The 450cc engine is the ultimate powerhouse when it comes to KTM's competitive motocross range. Significantly reworked for 2019, it features even more compact dimensions and reduced weight. It is fitted with a newly designed, extremely compact single overhead camshaft cylinder head and the latest electronic fuel injection. This enables the impressive 63hp to be distributed extremely efficiently throughout the rev range. Even with its super-beneficial electric starter this model is still the lightest 450 engine on the MX market.
- Cylinder head: Inside the SOHC cylinder head, an overhead camshaft controls four ultra-lightweight titanium valves via extremely rigid rocker arms, which are DLC-coated on the intake side. A configuration like this allows engine speeds of up to 11,500rpm; a baffling figure for a large displacement thumper. New lateral brackets, made of aluminum instead of steel, allow an efficient fixation of the engine to the frame and contribute to the bike's featherweight feel.
- Crankshaft: The 450 SX-F's crankshaft utilizes a short connecting rod, which makes for an overall compact and lightweight engine with a snappy power delivery. A plain big-end bearing with two force-fitted bearing shells runs directly on the crank pin. The necessary oil feed for this bearing is ensured by the engine's pressurized lubrication. This design is a decisive benefit in terms of the crankshaft service interval, which can be lengthened due to the plain bearing. So just pin it, all day long.
- Crankcases and engine covers: The design of the die-cast engine cases allows for minimal weight and a very centralized shaft configuration. This makes the engine short and compact, while contributing to an efficient centralization of masses. The engine covers also feature a solid surface structure, which reduces the wear caused by the rider's boots. This way, your SX-F will keep looking better longer.
- Transmission: The KTM 450 SX-F uses a lightweight 5-speed transmission with gear ratios that are perfectly matched to the power delivery of its large displacement engine. The 1st and 3rd gears are treated with a special surface coating for better reliability. An advanced ´No Dirt´ gear shift lever design prevents mud and sand from blocking the joint of the lever and guarantees trouble-free shifting. All 4-stroke engines are fitted with a gear position sensor, giving the option of different engine characteristics for each gear. For 2018, the transmission shaft gets a stronger shifting star and a C4 bearing that has a bigger overlap in the case. This guarantees better reliability even in extremely tough operating conditions.
- Engine management system: The state-of-the-art Keihin Engine Management System with electronic fuel injection features a 44mm throttle body. Thanks to its unique injector position, the engine's response is instantaneous. And to make life even easier, separate systems for cold starts and idle adjustment await you. The lightweight ECU features a unique traction and launch control system for lightning-quick response when the gate drops and maximum grip thanks to different maps that sync with to the gear you're in. It's also possible to unleash an even more powerful mapping via the handlebar map switch.
- Cylinder and piston: Inside the short cylinder, with a bore of 95mm, thumps a box-type piston made by CP. Its crown geometry is adapted perfectly to the high-compression combustion chamber, where its rigid structure and low weight shine. Thanks to the low oscillating masses, the engine is as snappy as it is strong.
- Balancer shaft: The side-mounted counter balancer does double duty also driving the water pump. Thanks to its perfect balance and low oscillating masses, engine vibration is kept to a minimum.
- Clutch: The 450 SX-F employs the KTM-developed DDS clutch (damped diaphragm steel) with a wear-free steel basket and extremely heat resistant clutch plates. This clever design employs a diaphragm spring instead of the usual coil springs, making for considerably easier clutch action. A diaphragm spring also leaves sufficient space for a damping system to be integrated into the clutch hub. The goal is traction, but durability is as well. A lighter basket, a reworked inner hub and a pressure plate providing better oil supply and unsurpassed cooling up the longevity of the DDS clutch. Light operation and telepathic amounts of control are standard with this hydraulic Brembo actuated clutch.
- E-Starter: Like all KTM 4-stroke motorcycles, the 450 SX-F is started at the push of a button - a priceless advantage when you're on the clock.
- Handlebar map select switch: All 4-stroke models are equipped with a sophisticated new multi-functional handlebar map select switch, which does three things:Activation of the traction controlActivation of the launch controlSelection of two power curves (Standard or Advanced)The traction control is a unique feature that none of the competitors can offer. It guarantees more efficient traction when the track conditions are less than perfect. Push the button and reign supreme. With this map select switch the rider can also activate the launch control, which provides more efficient starts out of the gate so you can go for the holeshot, time and time again. How? It simply reduces the maximum engine speed for the very first moments of the start, in order to give you better control. Push both buttons when the engine idles and the EFI control lamp mounted on the upper triple clamps will let you know you are READY TO RACE. In addition, the map select switch gives the rider the chance to select an alternative, more powerful map beside the standard configuration. Welcome to the future.
- Cooling: KTM's proven cooling system routes the coolant from the cylinder head through the frame triangle, directly to aluminum radiators made by WP. A new filler cap system and are stiffer alloy construction increase the durability and reliability of the cooling system. Due to flow optimized internal circulation and CFD-calculated air ventilation, the system is superbly efficient. In addition, well thought-out radiator guards integrated in the front part of the shrouds provide protection in a crash.
- Exhaust: Competition noise limits are a real challenge for every manufacturer. Therefore, KTM has put a lot of effort into the development of their exhaust systems. All 4-strokes are fitted with headers that have a unique standard feature; an additional resonator system - a small chamber connected to the pipe. All 4-strokes are fitted with a short silencer, mounted as close to the engine as possible. You know what that means: extra mass centralization and better rideability. Its advanced internal design reduces the noise sufficiently in order to sit safely below the noise limit, while still raising the hairs on your neck.
- The KTM 450 SX delivers metal twisting torque and requires a strong frame to cope with its immense power. For 2019, a new lightweight, high-tech steel frame was developed to further improve the power-weight-ratio, without compromising strength and durability. It features refined flex characteristics that ensure the bike soaks up those big hits while also maintaining excellent agility and high-speed stability. The chassis also features additional innovative elements, like "no dirt" foot pegs and new brackets for mounting an optional composite skid plate. Overall, every element of the chassis contributes to an intuitive, high-performance ride like no other.
- Frame: The high-tech, lightweight chrome-moly steel frame has a knack for easy handling, outlandish rideability, precise cornering and excellent stability. You can also count on high torsional rigidity and low longitudinal stiffness. This results in better absorption of the energy created from the front and rear suspension, sucking up jumps and bumps. In short: more comfort and less rider fatigue. Laterally attached, lightweight aluminum engine head stays (the connection between cylinder head and frame) contribute to more precise cornering and a reduced vibration level. The engineers were able to pull off all that, while making their frame 2.2 pounds lighter than that of the lightest competitor on the market. In addition, it is easier to maintain, easier to work on and supplies more space for the tank and other components. The bike also features an extra-light subframe made of aluminum, which tips the scales at less than 2 pounds.
- Swingarm: The cast aluminum design offers low weight and a perfect flex behavior. The single-component casting process eliminates any inconsistencies and inherent weak points created by welding. It's better looking too.
- Wheels: Featuring lightweight, CNC machined hubs and high-end Excel rims, they guarantee maximum stability and minimal unsprung weight. The wheels are shod with the latest Dunlop Geomax MX 3S tires.
- Front suspension: All full-size SX models are fitted with the super-lightweight WP AER 48 front fork. It is a 48 mm USD air-sprung fork with separate functions for each fork leg, meaning damping functions are on the right side and the air spring is on the left. The left leg features a two-chamber system with a capsuled air cartridge, helping prevent loss of air pressure. Essentially, this means that in the rare case of a leaking outer seal, the internal cartridge pressure keeps the bike in a normal position. The air spring is exceptionally easy to use and can be adjusted to any rider weight via a single air valve and the air pump that is supplied with the bike. The right fork leg integrates a damping cartridge to fit single damping leg requirements and can be adjusted to the track conditions and the rider's preferences. (compression from top, rebound from bottom, 30 clicks each). For 2019, new settings on the damping side have improved the damping characteristics, providing great front end feel and control.
- Rear suspension: The WP shock absorber has been developed with the entire frame and swingarm architecture in mind, including the linkage and the WP AER 48 front fork. It features machined and black anodized components and is a valuable, high-end product compared to roughcast reservoirs. A new, confidence inspiring setting with improved damping characteristics perfectly matches the front-end setup and its striking WP color scheme lets everyone know you have excellent taste in suspension.
- Triple clamp: Top quality, CNC machined triple clamps have been a KTM trademark for years to ensure precise handling. For 2017, the upper triple clamp specifically features a redesign in conjunction with the new fork tubes. The rubber damped handlebar mount has also been reworked and the lower handlebar clamps are now separated, while on the upper side a new bridge-type clamp guarantees more torsional stiffness and can easily be replaced in case it gets twisted due to a crash. In addition, an hour meter is fitted at the upper triple clamp in order to let the rider know it's time for a service.
- Brakes: You can't brake any harder, better, faster or stronger. These high-tech Brembo babies are combined with lightweight wave discs made by Galfer. For 2017, the rear brake features a 10mm longer brake pedal and you get new, less aggressive brake pads all round.
- Fuel tank: A lightweight polyethylene tank with a capacity of 1.85 gallons. The fuel tank cap has an inside thread, which makes for easy and reliable closure.
- Airbox: The airbox design offers maximum protection of the air filter while ensuring maximum airflow. The large twin-air filter is mounted in a stiff cage, which at the same time holds the system in place. This design is so simple, you could still pop a fresh one in with a face full of mud. Without tools. In seconds.
- When it comes to the powerhouse of KTM's SX range, it is imperative that a rider is able to shift his weight quickly and easily to work in unison with the motorcycle. KTM places a great deal of emphasis on creating the optimal ergonomics for high-level performance, making sure the neutral riding position offers the best control. A rider's main interaction with the motorcycle comes through the bodywork, seat, footpegs and handlebars and these crucial contact points play a vital role in balance and control. There is no doubt that the KTM 450 SX-F packs a serious punch and by ensuring the very best high-performance ergonomics, a rider has the confidence and control to use it as it is meant to be.
- Seat: All SX models have a newly shaped seat, designed to match the improved ergonomics. The seat cover features newly developed silicone strips that provide better feel and grip for the rider. The seat is conveniently fixed to the bike using one long, lateral screw, making it safe and easy to handle.
- Handlebar: KTM engineers sure know how to handle handlebars. This tapered one, made of high-strength aluminum by NEKEN, is fixed in damped rubber mounts and has two different positions. From 2017 onwards, the lower handlebar clamps are separated, while on the upper side a new bridge-type clamp guarantees more torsional stiffness. It's also easier to replace the bar in case it gets twisted in a nasty crash. ODI lock-on grips make grip changes easy which does not require any wire or glue to be secured.
- Footpegs: Sophisticated ´No Dirt´ footpegs prevent clogging of the footpeg pivot, even when digging in deep ruts. Looking for a higher riding position? Then just mount the footpegs of the 2018 EXC models, which are 6mm higher than the SX versions.
- Unloading a KTM 450 SX at the track is an immediate declaration of your race winning intentions. With the help of KTM factory riders, as well as KTM R&D and Kiska Design, they were able to further refine the bodywork of the entire SX range, achieving complete harmony between rider and bike, further enhancing this powerhouse's dominant appeal. Their main focus when designing the SX range was to provide contact points that allow maximum freedom of movement and improved overall handling. Brute strength at the lowest possible weight is what this bike is all about and can be seen in the intelligent I-beam design on the front and rear fenders, which guarantee maximum stability at no extra weight. The new aggressive-looking graphics were not only a necessary change, but were designed to send a clear message to the competition that this is not a bike that should be taken lightly.
- Decals: A new, tailor-made kit and a Factory orange frame. Because in this sport, champs deserve to look the part regardless of the dirt.
- With the KTM 450 SX-F producing a dirt ripping 63hp, every effort has been made to ensure the power is delivered in a controlled manner. Additional to the considerable mechanical effort to ensure usable delivery of the power is an electronics package with the ability to refine it to perfection. Activated by a multifunctional handlebar map switch, a rider has access to important features like traction control, launch control and even alternative power curves. Many hours were spent in development, creating mind-blowing power and torque. This made electronics a necessary innovation that ensures power gets to the ground in the most effective way. A proven electric starter gets this dirt-shredder fired up, ensuring the ultimate motocross experience starts with the simple push of a button.
- Battery & wiring harness: A strong new lithium ion battery breathes life into the engine and contributes to low vehicle weight. The lightweight battery and wiring harness are centralized in a compartment above the air filter box, allowing the mechanic to remove the subframe without moving the electronics. A happy mechanic is a good mechanic.
- Design: 1-cylinder, 4-stroke engine
- Displacement: 449.9 cm³
- Bore: 95 mm
- Stroke: 63.4 mm
- Starter: Electric starter
- Transmission: 5-speed
- Clutch: Wet, DDS 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
- 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"
- Steering head angle: 63.9 °
- Engine Type
- 1-cylinder, 4-stroke
- 449.9 cm³
- Bore and Stroke
- 95 mm x 63.4 mm
- Fuel System
- Keihin EMS
- Front Suspension
- WP-USD, AER 48, Ø 48 mm
- Front Brakes
- Disc brake
- Rear Suspension
- WP shock absorber with linkage
- Rear Brakes
- Disc brake
- Final Drive
- Chain: 5/8 x 1/4 in.