Motorcycle specifications KTM350 SX-F 2019 Between knife and club

The 350 SX-F is the ultimate compromise. A monster of power and agility, this 2019 version of the Katoche cross is even more advanced in terms of performance and torque. It now approaches a 450 in terms of power, but benefits from the agility of a 250. Lively and light, this bike has many assets and can count on its pedigree to win many laurels.

engine

as compact and light as ever (26.6 kg), the engine of the 2019 KTM 350 SX-F is more powerful than ever, thanks to a host of improvements. These include a new clutch, an optimized gearbox and a redesigned, lighter DOHC (double overhead camshaft) cylinder head. equipped with the latest electronic fuel injection system and a practical electric starter, it's ready for action at the touch of a button.

cylinder head

the cylinder head of the KTM 350 SX-F is an essential cog in the bike's wheel. The 2019 version has been redesigned to increase performance and save 200 grams, no mean feat. It features two overhead camshafts with ultra-fine, friction-optimized surfaces. These are responsible for actuating four titanium valves (intake: 36.3 mm, exhaust: 29.1 mm) using ultra-light, DLC-coated rockers. KTM engineers have worked wonders to maximize throughput and guarantee an optimum operating range. Performance is simply breathtaking throughout the rev range up to 13,400 rpm.

crankshaft

the KTM 350 SX-F's highly rigid crankshaft uses a shortened, lightweight connecting rod, which contributes to the engine's incredibly dynamic character and optimum power delivery. The connecting-rod bearing features two force-fitted half-bearings acting directly on the crankshaft crankpin. This design is the prerequisite for extremely high speeds and unrivalled power from the 350 cm3 engine. This design increases engine life and extends crankshaft service intervals.

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 KTM 350 SX-F is now equipped with a new, more robust 5-speed gearbox. The transmission ratios of the previous version have been retained, but the sprockets have all been improved and reinforced. Another highlight of the transmission is the "zero dirt" design of the selector. Designed on the same principle as the footrest, it prevents the accumulation of dust and enables the gearbox to remain operational in all conditions.

engine management

the Keihin engine management system with electronic fuel injection features a new 44 mm injection body. The unique 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. For added convenience, independent adjustment mechanisms have been provided for cold start and idle. The MAP sensor (absolute pressure sensor) has been made even more watertight, making the system even more reliable. Modifications to the throttle cable have simplified cable routing and made them more accessible. The control unit (ECU) on the 2019 models features new mappings adapted to the new exhaust and cylinder head design, with the aim of better managing traction control and starting control. To deliver maximum power, it adapts the engine's characteristics at each speed, according to the data communicated by the engaged gear sensor.

cylinder and piston

the 88 mm-bore cylinder houses a forged bridge-box piston of the highest quality, manufactured by CP. In addition to its extremely rigid structure, it features a unique crown shape to match the high level of compression in the combustion chamber. The high compression ratio (14:1) and reduced oscillating masses give the engine an extremely responsive character.

balancer shaft

the high rotational speeds of the KTM 350 SX-F engine generate considerable inertia. To compensate for this, the engine is fitted with a multifunction balancer shaft. In addition to its beneficial effect on vibration levels, this shaft also drives the timing chain and water pump.

clutch

the all-new DS (Diaphragm Steel) clutch transfers control to the rider's hands. It consists of a durable one-piece clutch housing and a main gear (made of ultra-high-strength billet steel), offering rock-solid reliability. Extremely heat-resistant steel motor friction discs are preloaded by a diaphragm spring to optimize clutch release. This type of design significantly reduces the force exerted on the clutch, even more so with the Brembo hydraulic system.

electric starter

the electric starter, available as standard on the KTM 350 SX-F, uses a proven drive system and Mitsuba's robust electric motor. The rock-solid reliability of this system saves precious time and effort at crucial moments of the race.

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 a unique function with a new setting on 2019 models. It ensures more efficient traction and better control of the bike during acceleration phases, especially on demanding tracks. This function can be activated, even at full throttle, using the map selector on the handlebars. When the engine is at idle, simply press both switches simultaneously to activate the start control as well, for a quicker jump off the grid. Thanks to a new set-up, start control can now take advantage of traction control to limit wheel slip and gain traction. In addition to the standard engine modes, the map selector gives access to other engine modes for maximum racing options.

muffler

the new exhaust system, fitted to all 4-stroke models, gives the engine a smoothness and liveliness that are hard to match. It features a new exhaust manifold (specific to the model) and a small additional chamber, i.e. an advanced resonator called FDH (Flow Design Header). The muffler benefits from a new aluminum casing and a new nozzle. The interior of the silencer has also been reworked. The new structure allows the exhaust to be disassembled without having to remove the shock absorber, and facilitates access to the latter. Another ergonomic advantage is the slimmer silhouette of the motorcycle, while respecting regulatory noise emission levels.

chassis

the KTM 350 SX is the ultimate combination of power and agility. Renowned for its handling, this model's chassis also offers excellent feedback to the rider. The 2019 model year features a new high-tech steel frame designed to give the rider valuable feedback on track conditions. The frame's flexibility has been optimized to absorb the biggest shocks and enhance 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 mounting brackets. Every element of the chassis contributes to a stronger, more intuitive riding experience.

frame

as with the rest of the SX range, the KTM 350 SX-F's chromium-molybdenum steel frame is made of hydroformed tubing. These tubes are robotically welded to guarantee the highest levels of quality. Frame rigidity has been optimized to enhance handling. The excellent cohesion with the suspension offers the perfect compromise between agility and high-speed stability. And with self-cleaning "zero-dirt" footrests that won't jam when returned to position, you're in complete control, whatever the conditions. All frames on 4-stroke models feature three new brackets to facilitate fitting of an optional composite protection shoe (offered in the KTM PowerParts range of accessories). The frames of the 2019 SX range inherit a highly resistant powder-coating (as on KTM Factory machines) and standard frame protectors. The new rear buckle, made of lightweight aluminum, has been lengthened by 40 mm. This improves the stability of the rear shell and facilitates mobility on the saddle.

swingarm

the KTM 350 SX-F benefits from a new monoblock swingarm, produced by high-pressure die-casting. This manufacturing process guarantees unfailing strength, while keeping weight to a minimum. To facilitate chain maintenance, the measurement marks on the swingarm are visible from above.

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 heads on the 2019 models have been redesigned to reduce the frequency with which spokes need to be re-tensioned. The wheels are shod with latest-generation Dunlop Geomax MX 3S tires, to maximize power transfer to the ground and enhance stability.

front suspension

all standard-size SX models feature the ultra-light WP AER 48 fork. The legs of this 48 mm inverted air fork have different functions: the damping functions are on the right, the air spring is on the left. The left fork leg 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 leg features a cartridge specially designed to meet the requirements of the single-arm damping design, and can be adjusted to suit track conditions or rider preference. Simply turn the 30-step knob to the desired position (compression up and rebound down). The new damping settings on the 2019 models have improved front-end control and feel.

rear suspension

the DDC shock absorber, present on all SX models, was developed with the new frame and swingarm architecture in mind, as were the linkage system and the AER 48 front 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. The settings and main piston inside the shock absorber have been redesigned to improve damping characteristics in conjunction with the new front-end setting. Fully adjustable for high-speed and low-speed compression, it can be specifically adapted to track conditions or rider preferences.

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

the ultra-light polyethylene fuel tank has a capacity of 7.0 liters. The internally threaded fuel cap ensures easy, reliable closure.

air filter housing

the air filter housing of the KTM 350 SX-F has been completely redesigned to optimize flow dynamics. Combined with the new intake snorkels, it ensures exceptional power delivery and acceleration. In addition to the obvious performance gains, the new 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 on previous models, the filter can be serviced in record time and without tools, a typically KTM feature.

ergonomics and comfort

the feeling of being at one with the bike depends essentially on the speed at which the rider can move around on the bike, and the efficiency of the manoeuvre. To give the rider perfect control, KTM engineers have taken great care to offer flawless ergonomics and optimum performance. To find a more natural and comfortable riding position, the rider can adjust the handlebar position to suit his or her preferences and the conditions. As the rider interacts primarily with the fairing, seat, footrests and handlebars, these contact points play a key role in balance and control. When it comes to ergonomics, KTM believes that only the best components can guarantee the feeling and level of control that riders have come to expect from the KTM 350 SX-F, and from the entire SX range.

saddle

the saddle on all SX models has been redesigned to confirm the improvements in ergonomics. The saddle cover now incorporates silicone strips to optimize grip and feel. A long screw on the side secures the saddle to the motorcycle, making handling easier and safer.

handlebars

all standard-size SX models feature the same tapered, ultra-strong 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. The handlebar foam has also been redesigned, as has the handguard, which is now much easier to fit and remove. These handlebars allow you to ride your bike like a 250, yet with the power of a 450.

software and electronics

the KTM 350 SX-F is a revolutionary motorcycle at the forefront of motocross innovation. Its state-of-the-art electronics make the most of its formidable power-to-weight ratio and optimize power delivery. The handlebar-mapped selector allows instant traction and start control, as well as the selection of different power curves. KTM engineers have taken mechanical performance to the extreme and developed electronics capable of transferring power to the ground as efficiently as possible. KTM SX-F models also have the advantage of a proven electric starter.

battery and wiring harness

to start the engine every time, especially in cold weather, the starter motor on SX-F models is powered by a new, ultra-light, high-performance 2 Ah lithium-ion battery. The voltage regulator/capacitor assembly now unites all electrical components under the seat, making the system even more reliable.

Images and info credits: KTM