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450 SX-F - 2019


Model Description

When maximum power is needed, there is no alternative to the stunning KTM 450 SX-F. Its performance has been demonstrated in the world's toughest competitions. Ryan Dungey rode the bike to win the AMA 450 Supercross World Championship 2017 and Tony Cairoli also rode it to win the MXGP World Championship. In model year 2019, the SOHC single-cylinder bike is more powerful than ever before. With its updated, compact SOHC engine, delivering even more explosive, but controllable power, it is the weapon of choice for Supercross and Motocross factory teams. Now fitted with a new chassis, the KTM 450 SX-F boasts outstanding handling and absolutely limitless stability, making it the fastest 450cc motocross bike KTM has ever built.
The KTM 450 SX-F is now fitted with a new 4-speed transmission, which is designed to ensure maximum durability and reliability. The gear ratios from the previous transmission system, which are perfectly matched to the performance characteristics of the large displacement single-cylinder engine, have been retained. KTM's advanced No-Dirt technology is used for the gear shift lever to prevent mud and dirt from fouling the lever joint and thus guarantees reliable gear changing at all times. A gear position sensor fitted as standard to all 4-stroke engines enables the engine management system to select the power curve that perfectly matches the gear currently engaged. The KTM 450 SX-F will be available on the US market with a 5-speed transmission, since US customers use the bikes on faster tracks and in the desert.
The newly developed SOHC cylinder head in the KTM 450 SX-F is far more compact than his predecessor, is 15 mm lower and 500 g lighter. This results in an optimized centralization of masses, resulting in further improved handling. A new overhead camshaft positioned closer to the center of gravity controls the intake and exhaust flow through optimized ports. This activates four ultra-lightweight titanium valves (intake 40 mm, exhaust 33 mm) via extremely rigid rocker arms, which are DLC (Diamond-Like Carbon) coated on the intake side. The actuating mechanism is now driven by a shorter timing chain and friction-optimized chain guides and makes engine speeds of up to 11,500 rpm possible. The new cylinder head guarantees more controllable power delivery and gives the KTM 450 SX-F unparalleled peak performance.

The KTM 450 SX-F is equipped with a DDS (damped diaphragm steel) clutch developed by KTM with a non-wearing steel outer clutch hub and extremely heat-resistant steel clutch plates. The clutch can be operated with little effort, due to the use of a diaphragm spring instead of conventional coil springs. The diaphragm spring also creates space to accommodate a clutch hub with integrated damping system for optimized traction and a long service life. The Brembo hydraulic clutch has an easy and precise action.

KTM has placed the crankshaft of the KTM 450 SX-F in an ideal position close to the center of gravity, which results in superb handling. A short connecting rod contributes to the compact design of this lightweight engine, which features a snappy power delivery, a well-balanced moment of inertia and – related to it – excellent traction and rideability. The crankshaft has a plain big (bottom) end bearing with two force-fitted shells running directly on the crank pin, which is lubricated by the engine's high-pressure lubrication system. This design benefits the bike owner, since crankshaft service intervals are extended.

The engine of the KTM 450 SX-F has a short and light cylinder with a bore of 95 mm. An extremely light bridged box-type piston keeps vibrations down and pushes up the rpm. It has a compression ratio of 12.75:1.
KTM has taken the successful KTM 450 SX-F powerhouse and upgraded it for model year 2019, giving it even more compact dimensions, with a weight reduced to 27 kg and explosive power delivery over the entire rpm range. Now fitted with a new, compact cylinder head and the latest electronic fuel injection, the engine now has an even better power delivery and delivers an unrivaled peak power of 62 bhp. Including the E-starter, this bike has the lightest 450cc engine in the entire motocross segment.

The KTM 450 SX-F employs a state-of-the-art Keihin engine management system with electronic fuel injection and a 44 mm throttle body. The instantaneous response of the engine, the virtually inexhaustible power and the perfect atomization of the fuel with the upstreaming air are due to the innovative positioning of the injector. There are also separate systems available for cold start and idle adjustments. A modified throttle cable mount provides for a more direct routing of the cables and much easier access. An optimized seal for the MAP (manifold air pressure sensor) means the system is now even more reliable than ever before. The control unit features new maps adapted to the new exhaust system and cylinder head and activates the traction and launch control functions. There are also different maps available for specific power curves depending on which gear is currently engaged. This information is provided by the gear position sensor.
The design of the die-cast engine case has enabled the weight to be reduced and the shaft configuration to be centralized. This has resulted in a single-cylinder engine that is both short and compact with excellent centralization of masses. The covers with their modern surface structure are designed to reduce wear caused by the rider's boots.
As is the case with all KTM 4-stroke bikes, the KTM 450 SX-F starts by simply pressing a button. Particularly when the going gets tough in motocross event, an E-starter can give the rider an invaluable advantage.
The side-mounted balancer shaft also drives the coolant pump. Due to the low oscillating masses of the 450cc engine and its perfect balance, vibration levels are kept to a minimum – even with the engine running at its highest rpm.

Model Specification


Engine Type

Single cylinder, 4-stroke


449.9 cc


Electric starter / Lithium Ion 12V 2.2Ah


4 gears

Engine Lubrication

Pressure lubrication with 2 oil pumps


Liquid cooled


Wet multi-disc DDS clutch, Brembo hydraulics


Keihin EMS



Central double-cradle type


5/8 x 1/4

Steering Head Angle

63.9 degrees

Tank Capacity

7 itres


Primary Gear Ratio


Secondary Gear Ratio


Brake System Front

Disc brake 260 mm

Brake System Rear

Disc brake 220 mm


Front Suspension

WP USD AER airforks 48 mm

Rear Suspension

WP shock absorber with linkage

Suspension Travel Front

310 mm

Suspension Travel Rear

300 mm



95 mm


63.4 mm


1485 mm

Ground Clearance (unloaded)

370 mm

Seat Height

950 mm

Weight (No Fuel)

100 kg