The 11 to 15-year-old riders of the junior class are no longer beginners. These are future champions fighting for victory, no matter if it is the for a National Championship or a local qualifier. In this scene, the new and improved KTM 85 SX is considered a winner's bike. With the most powerful engine in the field and a super lightweight, stable chassis, it does not need to shy away from a full size bike.
Cutting-Edge 2-Stroke Technology
- Engine: Cutting-edge 2-stroke technology, combined with a precise 6-speed transmission and hydraulic clutch are the foundation of the KTM 85 SX’s superiority in all junior racing competition. The new KTM 85 SX engine uses the latest technology to deliver unrivaled performance in the competitive 85cc class. With an unchanged bore and stroke, the engine is 1.5 pounds lighter and delivers improved power and rideability along the complete rev range. Key to the engine is a new power valve which allows the power delivery to be tailored simply and more effectively than before.
- Cylinder: The new cylinder has an unchanged bore and stroke (47/48.95mm) with new ports to improve performance and response. Additionally, it is designed around an all new power valve system. This system controls both the exhaust valve and the sub exhaust port for significantly improved power, torque and controllability. As a result, the KTM 85 SX receives a significant increase in mid-range performance reducing the need to use the clutch in loamy or sandy conditions. An adjuster screw allows the opening timing of the power valve to be adjusted to suit rider preference and track conditions and by changing between different power valve springs (available in the KTM PowerParts catalog).
- Crankshaft: The all-new crankshaft is now lighter with optimized balancing to reduce vibration and oscillating mass. Even after removing this weight, the rotational inertia of the crankshaft has increased by 1 pound, improving torque and rideability. Thanks to its perfectly sized lightweight connecting rod, the crankshaft is distinguished by minimum vibrations and maximum durability.
- Clutch: The hydraulic clutch mechanism by Formula ensures an easy clutch action and well-defined modulation on the KTM 85 SX. Replacing the previous coil spring design, the KTM 85 SX features a new diaphragm spring clutch. The new design is 0.8 pounds lighter, more compact and also benefits from added durability.
- Exhaust System: The new exhaust system is perfectly suited to the engine’s power characteristics and contributes to the outstanding performance and rideability. The pipe is made in a 3-dimentional stamping process by WP Performance Systems. Once the components are shaped they are robot welded to ensure the highest level of quality and durability. The new silencer is 50mm shorter, improving mass centralization.
- Crankcases: The crankcases are manufactured using a high pressure die-cast production process keeping wall thickness to a minimum while retaining strength and durability. The design of the new cases is more compact and aims at positioning the shaft arrangements as close as possible to the center of gravity for improved handling.
- Handlebar: The KTM 85 SX has a super strong, tapered handlebar made of high-quality aluminum alloy with a bend that’s perfect for motocross requirements. They get a new throttle assembly that allows for easy free play adjustment. ODI lock-on grips on the left side make grip changes easy and do not require any wire or glue to be secured.
- Brakes: The Formula braking system with radial calipers – four pistons in front, two in the rear – with lightweight wave brake discs – front 240mm diameter, rear 210mm – are the ultimate in terms of controlled action and braking performance.
- Cooling System: A constant temperature balance for consistent, high performance is ensured by an intelligent cooling circuit with integrated crankcase cooling and two radiators. It 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.
- Air Filter Box: What is good for the bigger KTM off-road bikes cannot be bad for the 85 SX: an air filter change can be done within seconds without tools.
- Wheels: Black coated high-end Excel rims, lightweight, CNC machined hubs and black spokes with lightweight aluminum nipples ensure the highest stability at minimum weight on the KTM 85 SX. The OEM MAXXIS tires are renowned for their perfect traction and outstanding performance.
- Frame: Professionally crafted by WP Performance Systems, the chromium molybdenum steel frame is constructed using hydro formed tubes joined by precision robot welding to ensure the highest level of consistent quality. The frame sees a weight saving of nearly a pound and features a new geometry aimed at tailoring flex characteristics for improved handling and comfort. As a result, and in conjunction with new laterally mounted cylinder head mountings, the torsional rigidity is increased by 7% while longitudinal stiffness is reduced by 25%. This allows the frame to move in harmony with the suspension effortlessly soaking up big hits while also delivering improved agility and high speed stability. Additionally, the frame is fitted with new ´No Dirt´ footpegs which prevent the build-up of dirt collected through deep ruts and muddy terrain. The simple but effective self-cleaning system ensures the footpeg returns to its original position providing complete control in all conditions. The frame is finished off in a highly durable powder coating with standard frame protectors.
- Subframe: Made from lightweight aluminum, the new subframe features a shorter and more compact profile. It is now 75mm shorter and 0.5 lb lighter, which not only contributes to the overall weight reduction but also improves mass centralization.
- Front Suspension: Up front, the WP AER 43 consists of a split fork design using a capsuled air spring in the left leg and the trusted oil damping system in the right leg. The new components offer a significant improvement in suspension performance with a reduction in weight of 2.2 pounds and an increase in wheel travel to 280mm total (+10mm). Additionally, adjustment is made simpler thanks to the single air pressure valve and supplied fork air pump for preload and easy access clickers for compression and rebound.
- Rear Suspension: On the rear, a specific version of the new WP Xplor PDS shock absorber is fitted to the KTM 85 SX. PDS stands for the unique progressive damping system developed by WP together with KTM which provides excellent sensitivity and at the same time outstanding bottoming resistance. Full adjustability of compression and rebound damping and preload are KTM standard.
- Bodywork: When scaled down to the proportions of an 85cc rider, the contact points and feeling remain the same allowing the younger riders to feel the same control and comfort found on the larger models. The improved ergonomics instill confidence while also leaving room for free and unrestricted movement thanks to the broader and flatter seat and one piece air filter box cover.
- Graphics: The cool graphic design provides a striking look based on the big bikes. Don’t be surprised when someone mistakes you for a grown-up.
- Design: 1-cylinder, 2-stroke engine
- Displacement: 84.9 cm³
- Bore: 84.9 mm
- Stroke: 48.95 mm
- Starter: Kickstarter
- Transmission: 6-speed
- Primary drive: 20:64
- Secondary gear ratio: 13:46
- Clutch: Wet, multi-disc clutch, Formula hydraulics
- EMS: Kokusan
The illustrated vehicles may vary in selected details from the production models and some illustrations feature optional equipment available at additional cost. All information concerning the scope of supply, appearance, services, dimensions and weights is non-binding and specified with the proviso that mistakes, printing, setting and typing errors may occur; such information is subject to change without notice.