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.
ENGINE & EXHAUST
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.
The 450 SX-F is fitted with a newly developed SOHC (single overhead camshaft) cylinder head which is much more compact, 15 mm lower and 500 gr lighter. The changes have further improved mass centralization, elevating handling to new levels of excellence. The new overhead camshaft is also closer to the center of gravity and features an improved surface and shorter valve timing for improved responsiveness. The four ultra-lightweight titanium valves (intake 40 mm, exhaust 33 mm) are activated via extremely rigid rocker arms. The rockers on intake side are DLC coated, allowing for impressive engine speeds up to 11,500 rpm. New low-friction chain guides have also been added to further support the increased engine levels. The new head configuration guarantees the most efficient delivery of the unrivalled power, keeping a strong edge over the competition.
The KTM 450 SX-F's crankshaft is located in an ideal position close to the center of gravity, contributing to better mass centralization. It utilizes a short connecting rod, which allows for a compact motor design and a snappier power delivery. The whole unit is extremely well-balanced, with the perfect amount of inertia for optimal traction and ride-ability. A plain big end bearing with two force-fitted bearing shells, runs directly on the crank pin, with the necessary oil feed for this bearing supplied by the engine's pressure lubrication. This design also enhances durability, allowing for long crankshaft service intervals - resulting in less effort and cost and more time spent on two wheels.
The 2019 KTM 450 SX-F uses a reworked transmission that further improves durability. There was no need to change the gear ratios as they have been perfectly matched to the power delivery of the large displacement engine. All four-stroke engines are fitted with a gear sensor, which provides the option of different engine characteristics for each gear, depending on engine load. An advanced "NO DIRT" gear lever design prevents dirt from building up and together with the new reliable gearbox, guarantees the next gear is always an easy click away.
CRANKCASES AND ENGINE COVERS
The compact engine cases are manufactured using a high pressure die-cast production process that helps with weight reduction, while retaining strength and durability. The design allows for optimal shaft arrangements close to the center of gravity, resulting in better mass centralization and easier ride-ability. Plus, the new engine covers feature a smart surface structure that reduces wear caused by the rider's boots, keeping them looking as fresh as the day you bought it.
ENGINE MANAGEMENT SYSTEM
The state-of-the-art Keihin Engine Management System, with electronic fuel injection, features a new 44 mm throttle body. The injector position is unique and guarantees optimal atomization of the fuel and air on the way to the combustion chamber, resulting in instant response and maximum performance when opening the throttle. There are also separate systems for cold starting and idle adjustment, while an improved seal of the MAP sensor (MAP = Manifold-Absolute-Pressure) makes the system even more reliable. A reworked throttle cable mount allows for easy access and smoother routing of the cables. Additionally for 2019, the ECU features new maps which have been adapted to the new exhaust and cylinder head, regulating traction and launch control. It also provides different maps for each gear, according to the information received from the gear sensor, ensuring maximum power as you shift through the gears.
CYLINDER AND PISTON
The 95 mm bore cylinder houses a lightweight, box-in-box type piston, made to the very highest standards. Its design contributes to the engine's low vibrations and overall engine speed strength. The compression ratio is at 12.75:1 and due to the low oscillating masses, the engine is not only powerful, but also displays extremely lively characteristics.
The multifunctional side mounted counter balance shaft masterfully balances all the oscillating forces, while also driving the water pump. It effectively keeps engine vibrations to a minimum, resulting in the smoothest ride even at the highest engine speeds.
The KTM 450 SX-F is fitted with the extremely durable, KTM-developed DDS clutch (damped diaphragm steel), with a wear-free steel basket and heat resistant clutch plates. It uses a diaphragm spring instead of the usual coil springs, which results in considerably easier clutch action. The diaphragm spring is also compact enough to allow for a damping system to be integrated into the clutch hub, contributing to better traction and durability. Additionally, the Brembo hydraulic system provides easy and precise clutch modulation.
The standard electric starter on the KTM 450 SX-F uses a proven starter drive and a strong starter motor made by Mitsuba. As demonstrated time and time again, it provides quick and reliable starting, saving you precious time and energy when you need it most.
HANDLEBAR MAP SELECT SWITCH
Within easy reach of the left grip on all four-stroke models, is a multifunctional handlebar map switch, which features the innovative control functions; traction control; launch control and alternative power curves (standard <-> advanced). The TRACTION CONTROL is a unique feature which has a new setting for 2019. It guarantees more efficient traction and better control when accelerating the bike, especially in challenging track conditions. It can be activated on the handlebar map switch while riding. With a simple push of the two buttons at idle speed, the rider can also activate LAUNCH CONTROL, ensuring the most effective launch out of the gate. Thanks to a reworked set-up, the Launch Control now benefits from directly from the Traction Control, reducing wheel spin for maximum possible traction. The map switch also gives the rider the chance to select an alternative power map, besides the standard configuration, providing him with options during the race.
The KTM 450 SX-F features a new one-piece swingarm, manufactured using a gravity diecast production process. With the exceptional strength required to withstand the tough conditions of motocross and the brutal torque of a 450cc, it has a 5 mm longer axle slot, giving riders more options when aiming for the ideal wheelbase setup for all conditions. This is all achieved at the lowest possible weight. The chain measurement markings on the swingarm are visible from above, for simpler and more accurate adjustment.
The frame on the KTM 450 SX-F is newly designed to better endure the extreme forces this powerhouse will put it through. For this reason, along with the rest of the 2019 SX range, its professionally crafted hydro formed Chromium Molybdenum steel tubes are robot welded, for the highest levels of consistent quality and strength. The increased frame stiffness improves handling response, while it is designed to work in harmony with the suspension, for improved comfort and better high-speed stability. The new frame features "no-dirt" footpegs that have a simple but effective self-cleaning system. This ensures the footpegs return to their original position, providing complete control in all conditions. All 2019 SX-F 4-stroke frames feature three new brackets for easy installation of an optional composite skid plate offered through the KTM PowerParts program. For 2019, all SX frames feature a highly durable powder coating, just like the KTM Factory machines, and come with standard frame protectors. The lightweight aluminum subframe is 40 mm longer, providing more rear fender stability and easier movement across the seat.
KTM uses lightweight, CNC-machined hubs and high-end Excel rims on all SX models, guaranteeing maximum stability and minimum weight. For 2019, the aluminum spoke nipples feature a reworked design, which conveniently reduces the frequency with which the spokes need to be tightened. The wheels are fitted with the latest Dunlop Geomax MX 3S tires, delivering maximum grip and stability and effectively transferring all the power to the ground.
All SX models feature top quality, CNC-machined triple clamps and have become somewhat of a KTM trademark. For 2019, the triple clamp has been reworked with stiffer upper clamps (22 mm offset for all models) to suit the reworked frame stiffness and flex characteristics of the latest WP AER forks. The result is a front end that works in perfect harmony with the frame, improving overall handling and stability. The rubber damped handlebar fixation reduces vibration and also allows for some adjustment with 2 different mounting positions. An hour meter is fitted as standard on the upper triple clamp on all SX models, keeping the rider informed of the number of hours spent tearing up the track and when the next service is due.
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.
All SX models feature a DDC monoshock, which has been developed to work as a complete unit with the entire frame and swingarm architecture, as well as the linkage system and the AER 48 forks. It features high-quality machined and anodized components, which add a touch of class and give it appeal beyond just a functional necessity. Internally, the shock houses an updated main piston and new settings that provide improved damping characteristics, perfectly complimenting to the reworked front-end setup. It is fully adjustable, including high and low speed compression, allowing you to set the shock up precisely to suit any track and rider's preferences.
A lightweight polyethylene tank with a capacity of 7.0 liters. The fuel tank cap has an inside thread, which makes for easy and reliable closure.
High-tech Brembo brakes have always been standard equipment on all KTM motocross bikes. Combined with lightweight wave discs, the renowned system provides the highest level of braking efficiency, enabling you to out-brake the competition.
The new airbox on the KTM 450 SX-F has been completely reworked to ensure better flow dynamics, and together with new intake snorkels, leads to optimal power and throttle response. Despite the obvious performance enhancements, the new design also offers maximum protection against soiling of the air filter. The large Twin-Air air filter is mounted on a cleverly designed stiff cage that minimizes incorrect installation. As found on previous models, filter maintenance is quick and easy and does not require tools - a standard, original feature from KTM.
ERGONOMICS & COMFORT
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.
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.
All full-size SX models are equipped with the same high-strength aluminum tapered handlebar, made by NEKEN. The handlebar is fixed in rubber damped mountings, which allow for two different positions. The handlebars come standard with an ODI vulcanized grip on the right side and a comfortable ODI lock-on grip, which does not require any wire or glue, on the left. They also feature a reworked bar-pad with a newly designed cover that can be attached and removed a lot quicker and easier. This bike's carefully chosen handlebars and grips are exactly what is needed to hang on to, and control this powerful beast.
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 MY2018 EXC models, which are 6mm higher than the SX versions.
BODYWORK & GRAPHICS
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.
A new, tailor-made kit and a Factory orange frame. Because in this sport, champs deserve to look the part regardless of the dirt.
SOFTWARE & ELECTRONICS
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
All SX-F models feature a new, more capable, super lightweight 2 Ah Lithium-Ion starter battery, ensuring even safer starting of the engine, especially in cold weather conditions. The packaging of the voltage regulator and condenser has been reworked to concentrate all the electrical components in a common area below the seat, making the entire system even more reliable.
1-cylinder, 4-stroke engine
Wet, DDS multi-disc clutch, Brembo hydraulics
25CrMo4 steel central-tube frame
WP-USD, AER 48, Ø 48 mm
WP shock absorber with linkage
Suspension travel (front)
Suspension travel (rear)
Front brake disc diameter
Rear brake disc diameter
5/8 x 1/4"
Steering head angle
Tank capacity (approx.)
Weight READY TO RACE (without fuel)
The illustrated vehicles may vary in selected details from the production models and some illustrations feature optional equipment available at additional cost.
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