2017 KTM 450 SX-F
If gold is what you’re after, a 450 SX-F is what you get. Thanks to its compact engine delivering explosive but controllable power, it’s the weapon of choice for the Red Bull KTM Factory Team and the champion, Ryan Dungey. This READY TO RACE bike rules the AMA Supercross Championship. Its secret? Precise handling and arm-stretching grunt. Winners - line up here.
- Engine: The hugely successful 450 SX-F powerhouse has extremely compact dimensions, strong performance throughout the rev range and a low weight; this is the lightest 450 engine on the MX market. But that doesn’t mean it’s not a heavyweight in terms of muscle. Fitted with a single overhead camshaft cylinder head and the latest electronic fuel injection, it pumps out an unrivaled 62hp. With KTM’s engineers working tirelessly to increase service intervals, this super stroker has the latest engine management technology on board and confidently shoots both amateurs and pros to the top of their time sheets.
- Cylinder Head: Inside the SOHC cylinder head, an overhead camshaft controls the gas flow through the ports. This activates 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.
- 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 rest assured and pin it, all day long.
- Engine Cases And 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 gem will keep on shining as it did on the day you bought it.
- Transmission: The 450 SX-F uses a lightweight 4-speed gearbox 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 lever design prevents mud and sand from blocking the joint of the lever and guarantees safe shifting. All 4-stroke engines are fitted with a gear sensor, giving the option of different engine characteristics for each gear. On the US market, the 450 SX-F is delivered with a 5-speed gearbox in order to leave the rest in your wake out in the desert.
- 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 bar drops and maximized grip thanks to different maps that sync with to the gear you’re in. As an ultimate bonus, the rider can unleash an even more powerful mapping via the handlebar map switch.
- Cylinder And Piston: Inside the short cylinder - featuring a bore of 95mm - sits an extremely light, box-in-box type piston that delivers a major contribution to the engine’s low vibrations while it handles high engine speeds with ease.
- Counter Balance Shaft: The side mounted counter balance shaft also drives the water pump. Thanks to its perfect balance and low oscillating masses, engine vibrations are kept to a minimum. Even when revving it all the way up to the maximum, just the way an SX-F likes it.
- 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, which makes for a considerably easier clutch action. A diaphragm spring also leaves sufficient space for a damping system to be integrated into the clutch hub. The goal was traction, yes, but durability as well. On top of that, it is fitted with a lighter basket, a reworked inner hub and a pressure plate providing better oil supply and unsurpassed cooling. Of course, light operation and telepathic amounts of control are what makes this particular clutch, a hydraulic Brembo clutch.
- 100.2 kg: KTM engineers just love dropping weight year after year. The result: the 2017 SX models are the slimmest, lightest dirt bikes out there. Even though the 4-strokes are equipped with an electric starter as a standard feature, while the competition still needs to be kickstarted. You can just focus on kicking ass.
- 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 a big fat kilogram 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 stable aluminum profiles, which tiptoes the scales at less than 900g.
- Footpegs: Sophisticated ´No Dirt´ footpegs prevent smudging up the pegs, even when digging in deep ruts. Looking for a higher riding position? Then just mount the footpegs of the MY2017 EXC models, which are 6mm higher than the SX versions.
- Airbox: The airbox design offers maximum protection of the air filter against soiling, 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.
- Exhaust: FIM 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 header pipes that have a unique standard feature; an additional resonator system – a small chamber connected to the pipe. For the 450 SX-F the engineers developed an even more advanced version called FDH (Flow Design Header) that provides better engine performance and reduced noise. Speaking of which: 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 FIM noise limit (112 dB(A) at 2 meter max.), while still raising the hairs on your neck.
- Handlebar: KTM engineers sure know how to handle handlebars. This tapered one, made of high-strength aluminum by NEKEN, is fixed in damped rubber mountings and has two different positions. From MY2017 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. An ODI volcanized grip sits on the right, while on the left side of the bar a comfortable ODI lock-on grip is mounted, which does not require any wire or glue to be fixed.
- 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.
- Fuel Tank: A lightweight polyethylene tank with a capacity of 7.0 liters of juice. The filler cap has an inside thread, which makes for easy and reliable closure.
- 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.
- Seat: Tailored to meet the needs of the world’s fastest backsides, this durable seat offers great comfort. For MY2017, a new cover pampers its riders even more with better feel and grip.
- Cooling System: KTM’s proven cooling system routes the coolant from the cylinder head through the frame triangle, directly to aluminum radiators made by WP. 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 spoilers provide protection in case of crashes.
- Monoshock: The WP monoshock has been developed with the entire frame and swingarm architecture in mind, including the linkage system and the WP AER 48 front forks. It features machined and black anodized components and is a valuable, high-end product compared to roughcast reservoirs. A new setting and a softer spring perfectly match the reworked front-end set-up and its sparkling WP color scheme lets everyone know you have excellent taste in suspension.
- Forks: The lightweight WP AER 48 front fork, a 48mm USD air-sprung fork developed by WP in close collaboration with KTM, is a split fork with separate functions for each leg. That means damping functions are on the right side, whereas the air spring is in the left. This left leg features a two-chamber system with a capsuled air cartridge to prevent loss of air pressure. Should the outer seal start to leak, the internal cartridge pressure will keep the bike in position. The air spring is easy to adjust to any rider weight via a single air valve. No special tools are required; the air pump supplied with the bike will do just fine. The right fork leg integrates a damping cartridge that tailors to all your damping needs. It can be adjusted to the track conditions and the rider’s preferences with a twist of a dial (compression from the top, rebound from the bottom, 30 clicks each). For MY2017, the AER 48 also features redesigned outer tubes with better bending characteristics, smoother operation and less friction. Plus: they’ve lost some weight (265g). Right off the dealer floor, these forks are more comfortable and more sensitive than ever. But you can still hammer the hell out of them.
- 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 MY2017, the upper triple clamp specifically features a redesign in conjunction with the new fork tubes. The rubber damped handlebar fixation 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. Or a cold drink.
- Brakes: You couldn’t brake any harder, better, faster or stronger. These high-tech Brembo babies are combined with lightweight wave discs made by Galfer. For MY2017, the rear brake features a 10mm longer brake pedal and you get new, less aggressive brake pads all round.
- Handlebar Map Switch: All 4-stroke models are equipped with a sophisticated new multi-functional handlebar map switch, which does three things: Activation of the traction control; Activation of the launch control; Selection of an alternative power curve (Standard or Advanced),The traction control is a unique feature none of the competitors can offer so far. It guarantees more efficient traction and better control of the bike when accelerating. You’ll especially notice this on a rainy day. Push the button and reign supreme. With this map 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 moment 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 your bomb is live. In addition, the map switch gives the rider the chance to select an alternative, more powerful map beside the standard configuration. Don’t you just love the idea of a boost button?
- Battery & Wiring Harness: All SX-F engines are fitted with the proven electric starter – a unique KTM feature and a major benefit at all levels of motocross racing. A super compact and lightweight 495g Lithium-Ion starter battery breathes life into the engine and contributes to low vehicle weight. The battery and wiring harness are centralized in a compartment above the airbox, allowing the mechanic to remove the subframe without getting in conflict with the electrics. Because a happy mechanic, is a good mechanic.
- Electric 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.
- Bodywork: KTM R&D, Kiska Design and all our factory riders had their say in shaping the plastics. Their goal: complete harmony between rider and bike. And so it turned out. Perfect ergonomics and contact points, maximum freedom of movement, a low seat height and sweet comfort, especially in the rear part of the seat. The I-beam structures of the front and rear fenders are prime examples of such an intelligent design, guaranteeing maximum stability and a low weight thanks to well thought-out construction and mounting. Plus: they stay cleaner for longer.
- Graphics: A new, tailor-made kit, fit for a king. Because in this sport, champs deserve to look the part regardless of the dirt.
- Design: 1-cylinder, 4-stroke engine
- Displacement: 449.9 cm³
- Bore: 95 mm
- Stroke: 63.4 mm
- Starter: Electric starter
- Transmission: 5-speed
- Primary drive: 31:76
- Secondary gear ratio: 13:48
- 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
- Suspension travel (front): 310 mm
- Suspension travel (rear): 300 mm
- 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 °
- Wheelbase: 1485 ± 10 mm
- Ground clearance: 370 mm
- Seat height: 960 mm
- Tank capacity (approx.): 7 l
- Weight READY TO RACE (without fuel): 100.6 kg
- Engine Type
- 1-cylinder, 4-stroke engine
- 449.9 cm³
- Bore and Stroke
- 95 x 63.4 mm
- Front Suspension
- WP-USD, AER 48, Ø 48 mm
- Front Brakes
- Disc brake
- Rear Suspension
- WP shock absorber with linkage
- Rear Brakes
- Disc brake
- Dry Weight
- 100.6 kg
- Fuel Capacity
- 7 L
- 1485 ± 10 mm
- Ground Clearance
- 370 mm
- Seat Height
- 960 mm
- Final Drive
- Chain: 5/8 x 1/4 in.