Motorcycle specifications KTM350 SX-F 2018 Wasp or hornet

Since Tony Cairoli's first MX1 World Championship win in 2010 aboard a KTM 350 SX-F, the Red Bull KTM rider has dominated the class, winning five consecutive World Championship titles on this agile yet powerful machine. This is hardly surprising: the bike is almost as fast as a 450, but has the agility of a 250.

eNGINE

the engine of the KTM 350 SX-F benefits from a compact, lightweight structure (27.2 kg). Double overhead camshafts (DOHC), ultra-light titanium valves and DLC-coated rockers contribute to the engine's vigorous temperament. equipped with the latest electronic fuel injection system and an electric starter, it offers an extremely wide operating range, high performance and exceptional handling. Featuring the same engine configuration as the KTM 250 SX-F, it also resembles a 250 in its playfulness, achieved mainly by minimizing moving masses.

cRANKSHAFT

the cylinder head reveals two overhead camshafts with DLC-coated rockers (designed to minimize friction) and high-flow ports. Four ultra-light titanium valves maximize flow for optimum operating range, and deliver breathtaking performance throughout the rev range up to 13,400 rpm, for a maximum output of 58 HP. Aluminum side brackets have been added to secure the engine to the frame and lighten it by a few extra grams.

cRANKSHAFT

the crankshaft of the KTM 350 SX-F uses a shortened connecting rod. More compact and lighter, the engine also gains in responsiveness. The crankshaft features a connecting-rod bearing and two bearing shells press-fitted directly into the crankpin. This bearing is supplied with oil from the engine's pressure lubrication system. This type of design, combined with the connecting-rod bearing, greatly extends the crankshaft's service interval.

bALANCING SHAFT

to balance mass forces, the new KTM 350 SX-F engine uses a multifunctional balancer shaft that simultaneously drives the water pump and timing chain.

cYLINDER AND PISTON

the shortened 88mm-bore cylinder houses a proven bridge-box piston manufactured by CP. The geometry of the piston head, perfectly adapted to the new high-compression combustion chamber (14:1), features a rigid structure and reduced weight. Reduced oscillating masses give the engine an extremely responsive character.

eLECTRIC STARTER

the KTM 350 SX-F comes with an electric starter as standard, a decisive advantage when it comes to reducing lap times in competition. Operated at the touch of a button, this ultra-powerful electric starter made by Mitsuba is not about to let you down, especially as it now features an O-ring seal capable of withstanding extreme temperatures.

eNGINE MANAGEMENT SYSTEM

the Keihin electronic injection engine management system features a 44 mm throttle valve body. Thanks to the injector's unique position, engine response is instantaneous. And for added convenience, there are independent adjustment systems for cold start and idle. The ultra-lightweight control unit manages a unique traction and start control system to deliverthe ultra-lightweight control unit manages a unique traction and start control system to give you a helping hand when the going gets tough, and optimum driveability thanks to different engine maps adapted to the gear you're in. A more powerful engine mode, selectable via the power curve knob, even enhances your machine's aggressive character.

gEARBOX

to enhance the reliability of the 5-speed gearbox, the sprocket surfaces have been specially treated for 2nd, 3rd and 4th gears. The "zero dirt" design of the selector avoids clogging and jamming of the lever joint for safer gear changes. All 4-stroke engines are equipped with an engaged-gear sensor to adapt engine characteristics to each gear. On the AM18, the gearbox shaft features a new C4 bearing with greater radial clearance. This enhances reliability, even under extreme operating conditions. Enough to get you out of the sand in the middle of a Grand-Prix.

cRANKCASES AND COVERS

the design of molded crankcases has a dual benefit: maximum weight reduction and a highly centralized shaft configuration, to make the engine even more compact and achieve a much more efficient weight distribution. The new crankcase covers feature a solid surface structure designed to reduce wear caused by the rider's boots.

eMBRAYAGE

the KTM 350 SX-F uses a CSS (Coil Spring Steel) clutch developed by KTM. a sturdy steel clutch housing, heat-resistant clutch plates and new nitrate-treated steel liners that are less prone to wear. The clutch is activated by a hydraulic system manufactured by Brembo, which plays an essential role in the clutch's progressiveness and smoothness.

fRAME

the high-tech chromium-molybdenum steel frame is a model of lightness, flexibility and handling.the high-tech chromium-molybdenum steel frame is a model of lightness, flexibility and maneuverability, offering excellent stability and diabolical precision when cornering. Thanks to its high torsional stiffness and low longitudinal rigidity, this frame better absorbs the energy generated by the front and rear suspensions when jumping or negotiating a bump. The ride is more comfortable and less tiring. The aluminum brackets that link the cylinder head to the frame are as light as ever. Side-mounted, they also help to limit vibration levels and refine the bike's trajectory in bends. The engineers can be proud of their work, as the frame is now one kilo lighter than the lightest competing frame on the market today. Every effort has also been made to facilitate maintenance and free up space for the fuel tank and other components. The ultra-light rear section, made of stable aluminum profiles, weighs in at less than 900 grams.

wEIGHT

year after year, KTM engineers strive to make their bikes lighter. The result is clear: the 2018 KTM SX models are among the lightest and sleekest motocross bikes on the market. The 4-strokes are equipped as standard with a highly beneficial electric starter, whereas competing models still have to be kick-started.

fOOTREST

sophisticated "zero-dirt" footrests prevent the pivot from fouling, even when riding in deep ruts. Riding position not high enough? No problem! The footrest mounting system on AM 2018 EXC models has been raised by 6 mm compared to the SX versions.

eXHAUST SYSTEM

meeting the FIM's recommended noise emission levels is a real challenge for all manufacturers. That's why KTM has spared no effort to develop a state-of-the-art exhaust system. As standard, all 4-stroke models feature exhaust manifolds connected to a small additional chamber called the resonator. They are also fitted with a relatively short silencer, mounted as close as possible to the engine. This has the dual advantage of centralizing mass and enhancing driving pleasure. The internal design has also reached a significant degree of sophistication to keep noise levels well below recommended thresholds, while guaranteeing maximum rider sensations.

aIR FILTER HOUSING

the air filter housing protects the air filter from clogging and ensures optimum air flow. The cage housing the extra-large Twin Air air filter is totally rigid, helping to hold the system in place. The design is so simple that you could replace the filter even with your face covered in mud. And without the need for any tools. And in a matter of seconds.

oSCILLANT ARM

as well as saving weight, cast aluminium is ideal for bending. The one-piece casting process eliminates the imperfections inherent in welding, guaranteeing not only more homogeneous, but also more meticulous manufacturing quality.

gUIDON

when it comes to handlebars, KTM engineers have always known which way to go. Profiled and made of high-strength aluminum, these handlebars are no exception to the rule. It features rubber shock-absorbing pads and can be adjusted to two positions. The ODI handlebar is easy to change when needed, thanks to its glueless, wire-free mounting system.

fUEL TANK

the ultra-light polyethylene fuel tank has a capacity of 7 liters. The internally threaded fuel cap ensures easy, reliable closure.

wHEELS

featuring ultra-light CNC-machined hubs and top-of-the-range Excel rims, the wheels guarantee maximum stability despite limited unsprung weight. They are fitted with the latest-generation Dunlop Geomax MX 3S tires.

fORK TIPS

high-quality CNC-machined fork crowns, which ensure ultra-precise front-end handling, have been a KTM trademark for years. Two positions are possible for the handlebar trigger guard with shock absorbers. The hour meter indicates when it's time for an overhaul.

fORK

another interesting new feature on this bike: the WP AER 48 inverted fork with air spring and separate damping circuits, developed by WP in close collaboration with KTM. The damping functions are on the right, the air spring on the left. The left fork arm features a double-chamber air cartridge system to prevent any loss of pressure. Should the outer seal leak, the pressure exerted inside the inner cartridge will hold the bike in position. The air spring is easily adjusted to the rider's weight using a single valve. No special tools are required: the air fork pump supplied as standard will do the trick. The right-hand fork leg features a cartridge specially designed to adapt to the type of damping required. Simply turn the 30-notch knob to the desired position (compression up and rebound down) to select the appropriate setting according to track conditions and rider preference. More comfortable and responsive than ever, this fork (with revised damping characteristics) is just waiting to be put through its paces.

dAMPER

the WP shock absorber was developed with the frame and swingarm architecture in mind, as were the pushrod system and the WP AER 48 fork. With its various machined and black-anodized components, this ultra-sophisticated shock absorber makes a strong impression compared to less well finished competing products. It features a new, confidence-inspiring tuning and optimized damping characteristics that go hand in hand with the front-end setting. The shock absorber's gleaming colors are typical of the WP brand.

bRAKES

these little jewels of technology are combined with Wave brake discs renowned for their lightness. More responsive, more efficient and more powerful than ever, Brembo brakes will cope with any situation.

hANDLEBAR-MOUNTED POWER CURVE BUTTON

all 4-stroke models feature a new handlebar-mounted power curve switch that fulfills the following three roles: Activating traction control - Engaging start control - Selecting an alternative power curve (Standard or Advanced). Traction control is a feature found on no other competing model to date. It ensures more efficient traction when track conditions leave something to be desired. A simple press of a button and the job is done. This power curve change button also engages the start control. A successful start and you're guaranteed a holeshot. The principle is simple: the start control reduces the engine's maximum speed at the precise moment when you start, so that you can keep better control of your machine. Press the two buttons when the engine is idling, and the EFI indicator lamp on the upper fork crown lights up to warn you that the bike is in READY TO RACE mode. In addition to the standard engine maps, there's another, even more powerful engine mode.

eLECTRIC STARTER

like all KTM four-stroke motorcycles, the 350 SX-F can be started at the touch of a button, an undeniable advantage when it comes to setting a new lap time.

bATTERY AND WIRING HARNESS

the starter motor is fitted with a powerful lithium-ion battery, which represents a significant weight saving compared to the previous model. The battery and wiring harness are grouped together in a compartment above the air-filter housing, so as not to be hindered by the electrical circuit when removing the buckle. Mechanics and do-it-yourselfers will appreciate this.

gRAPHICS

custom deco kit, Factory orange frame: every detail counts, because in this discipline, there's nothing more beautiful than a car that stands out from the crowd.

cARENAGE

all KTM factory riders collaborated on the bike's design with KTM R&D specialists and the Kiska design agency, with a single watchword: to create perfect harmony between rider and machine. The result is convincing. Ergonomics and rider contact points have been carefully designed to enhance freedom of movement and comfort on the SX-F. The special shape of the front and rear mudguards guarantees maximum stability and minimum weight, thanks to a well thought-out structure and assembly. Best of all, they stay clean longer.

Information and images: KTM