KTM 250 SX 2018

ENGINE

The engine of the KTM 250 SX has been known and respected for being the most powerful 2-stroke engine in its class. 2-strokes really do have a future at KTM. Their outstanding power-to-weight ratio, low cost and simplicity see to that. The KTM 250 SX engine has been optimized for mass centralization, comes with a twin-valve controlled power valve, a balancer shaft for less engine vibrations, a 5-speed transmission and a hydraulically operated DDS clutch. This compact firecracker truly outshines the competition with its ripping performance and is the right choice for lovers of low purchasing and maintenance costs. Oh, and of course don’t forget that belly tingling 2-stroke snarl when you’re on the pipe.

CYLINDER

This compact cylinder with a 66.4mm bore features a cutting-edge power valve unit with a sophisticated mechanism for the lateral support exhaust ports. Matched to a twin-component cylinder head, it is KTM’s secret to all-round grunt. The layout of the water jackets in the cylinder and head guarantees efficient heat dissipation when the going gets tough.

CRANKCASES

These die-cast crankcases allow the implementation of a balancer shaft. So your ride will be as relaxed as it is rapid. Plus, your new favorite engine will keep looking as fresh as the day you bought it: its engine covers feature a smart surface structure in order to reduce the wear caused by the rider’s boots.

TRANSMISSION

A robust 5-speed transmission, its gear ratios perfectly in sync with the 250’s power band. An advanced ´No Dirt´ gear shift lever design prevents mud and sand from blocking the joint of the lever and guarantees trouble-free shifting.

BALANCER SHAFT

Say goodbye to numb feet and hands. This engine design allows the implementation of a lateral balancer shaft in order to keep the vibrations to a minimum. You know what that means: more comfort, bigger smiles.

CLUTCH

The KTM 250 SX employs the KTM-developed DDS clutch (damped diaphragm steel) with a robust steel basket, extremely heat resistant clutch plates and new, nitrated steel liners reducing the wear. This clever design employs a diaphragm spring instead of the usual coil springs, making for considerably easier clutch action. A diaphragm spring also leaves sufficient space for a damping system to be integrated into the clutch hub. The goal is traction, but durability is as well. Light operation and telepathic amounts of control are standard with this hydraulic Brembo actuated clutch.

CARBURETOR

The KTM 250 SX is fitted with a MIKUNI TMX carburetor. This 38mm flat slide carb lives to provide smooth and controllable power all the way up to the rev limitation. With a new intake manifold the carburetor is turned 7° in order to reduce the overflow of fuel.  And it’s less sensitive to different altitudes and temperatures, so you can pin it wherever, whenever.

EXHAUST SYSTEM

The engineers meticulously tuned the resonator chamber for maximum torque and power, so this little screamer is as tough as it is strong.

IGNITION

All 2-stroke models feature a new CDI control unit with an advanced hardware which improves the starting behavior of the engine. The ignition curves remain unchanged.

FEATHERWEIGHT

KTM engineers just love dropping weight year after year. The result: the 2018 KTM SX models are the slimmest, lightest dirt bikes out there.

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 engine head stays (the connection between cylinder head and frame) contribute to 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 MY2018 EXC models, which are 6mm higher than the SX versions.

AIR FILTER BOX

The air filter box 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

HANDLEBAR

KTM engineers sure know how to handle handlebars. This tapered one, made of high-strength aluminum, is fixed in damped rubber mounts and has two different positions. ODI lock-on grips make grip changes easy and do not require any wire or glue to be secured.

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. The fuel tank 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.

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. Thanks to flow optimized internal circulation and CFD-calculated ventilation, the system is superbly efficient. In addition, new radiator protections improve heat dissipation. Especially in the mud. They are also integrated into the front part of the shrouds to protect the radiators in a crash.

SHOCK ABSORBER

The WP shock absorber has been developed with the entire frame and swingarm architecture in mind, including the linkage and the WP AER 48 front fork. It features machined and black anodized components and is a valuable, high-end product compared to roughcast reservoirs. A new, confidence inspiring setting with improved damping characteristics perfectly matches the front-end setup and its sparkling WP color scheme lets everyone know you have excellent taste in suspension.

FORK

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 2-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 fork 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). Right off the dealer floor, this fork (with reworked damping characteristics) is more comfortable and more sensitive than ever. But you can still hammer the hell out of it.

TRIPLE CLAMP

Top quality, CNC machined triple clamps have been a KTM trademark for years to ensure precise handling. The rubber damped handlebar fixation allows for two positions and an hourmeter is fitted in order to let the rider know it’s time for a service.

BRAKES

These high-tech Brembo babies are combined with lightweight wave discs. You couldn’t brake any harder, better, faster or stronger.

BODYWORK

KTM R&D, KISKA Design and all our factory riders had their say in shaping the plastics with one goal: complete harmony between rider and bike. Perfect ergonomics and contact points provide maximum comfort in movement on the SX. The I-beam structures of the front and rear fenders guarantee maximum stability and a low weight thanks to well thought-out construction and mounting. They also stay cleaner for longer.

GRAPHICS

A new, tailor-made kit and a Factory orange frame. Because in this sport, champs deserve to look the part regardless of the dirt.