250 SX-F TROY LEE DESIGNS 2021

Engine

Unrivalled power

Renowned as the strongest engine in MX2 competition, the 2021 version maintains its dominance. Its compact structure contributes to excellent mass centralization, which supports the easy ride-ability of the bike. The addition of the Akrapovič silencer makes the KTM 250 SX-F TROY LEE DESIGNS a real force to be reckoned with.

Cylinder head

An integral part of the class-leading power delivery is the cutting-edge DOHC (double overhead camshaft) cylinder head. It features two overhead camshafts which activate the titanium valves (intake 32.5 mm, exhaust 26.5 mm) via the super-light, DLC coated finger followers. The camshafts have a friction-optimized super-fine surface and a timing that delivers incredibly refined power.

Crankshaft

The KTM 250 SX-F TROY LEE DESIGNS has a rigid crankshaft and a connecting rod that features a plain big end bearing with two force-fitted bearing shells run directly on the crank pin. This design was essential for the extremely high engine speeds and unrivalled maximum power of the 250 cc 4-stroke engine. The design also enhances the engine's durability, allowing long crankshaft service intervals, which is a huge benefit in relation to time, effort and cost.

Crankcases and engine covers

The compact engine cases are manufactured using a high pressure die-cast production process that helps with weight reduction, while retaining strength and durability. The design allows for optimal shaft arrangements close to the center of gravity, resulting in ideal mass centralization and easier ride-ability. The engine covers feature a smart surface structure that reduces wear caused by the rider's boots, keeping them looking as fresh as the day you bought it.

Transmission

The KTM 250 SX-F TROY LEE DESIGNS is fitted with a robust 5-speed transmission. The gear ratios were carried over from its predecessor and are perfectly suited for the MX track. Another highlight of the transmission is the 'no-dirt' gear shifter. Similar to the footpeg design, it prevents the build-up of dirt and ensures the next gear is always available, no matter what the conditions.

Engine management system

The state-of-the-art KEIHIN Engine Management System, with electronic fuel injection, features a 44 mm throttle body. The injector position guarantees optimal atomization of the fuel and air on the way to the combustion chamber, resulting in instant response and maximum performance when opening the throttle. There are also separate systems for cold starting and idle adjustment. The ECU features maps which have been developed to precisely match the exhaust and cylinder head, with options for regulating traction and launch control. It also provides different maps for each gear, according to the information received from the gear sensor, ensuring maximum power as you shift through the gears.

Cylinder and piston

The 78 mm bore cylinder houses a lightweight, forged, bridged, box-type piston, made to the highest standards by CP. It has an extremely rigid structure and features a unique crown shape to suit the high-compression combustion chamber. The compression ratio is at 14.4:1 and thanks to the combination of low oscillating masses, the engine displays extremely lively characteristics.

Balancer shaft

In order to balance the mass-forces the KTM 250 SX-F TROY LEE DESIGNS produces, the engine is fitted with a multifunctional counter balance shaft. It effectively reduces vibration, while driving the water pump and timing chain.

Clutch

The DS (diaphragm steel) clutch, literally puts the control back in the hands of the rider. It features a durable, one-piece clutch basket and primary gear, made of high-strength billet steel, guaranteeing unbeatable reliability. It is fitted with extremely heat-resistant steel carrier friction discs, which are pre-tensioned by means of a diaphragm spring, ensuring the most effective disengagement of the clutch. This design substantially reduces the operating force required to pull the clutch and is made even easier with the Brembo S.p.A hydraulic system.

E-Starter

Time is crucial in the heat of the race and an electric starter gets you fired up and back in the battle as soon as possible. The electric starter is standard on the KTM 250 SX-F TROY LEE DESIGNS and features a strong starter motor made by MITSUBA. The proven starter drive guarantees efficient and reliable starting when you need it most.

Handlebar map select switch

Within easy reach of the left grip on all four-stroke models, is a multifunctional handlebar map switch, which features the innovative control functions: traction control, launch control and alternative power curves (standard - advanced). The map switch also gives the rider the chance to select an alternative power map besides the standard configuration, providing more options during the race. The KTM 250 SX-F TROY LEE DESIGNS is the first model to feature the Connectivity Unit as standard, thus enablich wireless connectivity with the innovative myKTM app right out of the crate.

Cooling

Maintaining the optimal engine temperature is crucial to ensuring consistent horsepower throughout the ride. The KTM 250 SX-F TROY LEE DESIGNS features radiators which are positioned for a lower the center of gravity. Their design matches the shrouds perfectly and offers a great slim feel to the ergonomics. By using CFD technology (computational fluid dynamics) together with a clever coolant circuit routing, the innovative system ensures the optimum engine temperature for the highest performance, no matter what the conditions. The radiators also feature special protectors that don't only serve as protection from flying rocks and debris but also as a brace that disperses energy around the radiators in the event of an impact.

Exhaust

The KTM 250 SX-F TROY LEE DESIGNS comes with an Akrapovic Slip-On silencer as stadard that further improves the rider's feeling and this unique bike's aesthetics.

Frame

The frame on the KTM 250 SX-F TROY LEE DESIGNS has to cater for the dynamic riding styles typical of the class it fits into. As with the entire SX range, the frame is professionally crafted from hydro-formed chromium molybdenum steel tubes that are robot welded to ensure the highest levels of consistent quality. The carefully calculated stiffness of the frame delivers responsive handling and works perfectly with the suspension to provide excellent agility and high-speed stability. All 2021 KTM SX frames feature a highly durable powder coating and come with standard frame protectors. The subframe is made from lightweight aluminum and provides great feeling for the rider, as well as easy movement across the seat.

Swingarm

The one-piece swingarm, is manufactured using a gravity die-cast production process, for exceptional strength at the lowest possible weight. It offers a wide range of adjustment for the rear wheel, allowing for a shorter wheelbase on tighter twisty tracks, or a longer wheelbase for greater stability on longer, more choppy tracks. The swingarm's chain measurement markings are visible from above, making adjustment simpler and more accurate.

Wheels

The KTM 250 SX-F TROY LEE DESIGNS machine is fitted with high-end Factory wheels. They feature black D.I.D DirtStar rims and fully CNC-machined orange anodized hubs. Together with black spokes and orange anodized aluminum nipples, they guarantee minimal weight at maximal stability so that the rider will feel an increase in handling. Dunlop Geomax MX 33 tires put the power to the ground using the proven block-within-a-block design.

Front suspension

The KTM 250 SX-F TROY LEE DESIGNS is fitted with the super-lightweight WP XACT fork with AER technology. It is a 48 mm USD air-sprung fork with separate functions in each fork leg, with damping functions on the right side and the air spring on the left. The left leg features a two-chamber system with a capsuled air cartridge, helping prevent loss of air pressure. Essentially, this means that in the rare case of a leaking outer seal, the internal cartridge pressure keeps the bike in a normal position. The air spring is exceptionally easy to use and can be adjusted to any rider weight via a single air valve and the air pump that is supplied with the bike. The right fork leg integrates a damping cartridge to fit single damping leg requirements and can be adjusted to the track conditions and the rider's preferences. Additionally, the fork top caps have a new design for improved, easy adjustment(compression from top, rebound from bottom, 30 clicks each).

Rear suspension

The KTM 250 SX-F TROY LEE DESIGNS features a WP XACT monoshock, which has been developed to work as a complete unit with the entire frame and swingarm architecture, as well as the linkage system and the WP XACT fork. It features high-quality machined and anodized components, which add a touch of class and give it appeal beyond just a functional necessity. It is fully adjustable, including high and low speed compression, allowing you to set the shock up precisely to suit any track and rider's preferences.

Triple clamp

The KTM 250 SX-F TROY LEE DESIGNS features factory triple clamps anodized in orange. The triple clamp has a precisely calculated stiffness and adjustable offset (20 - 22 mm) to match the flex characteristics of the frame and fork. The result is a front end that all works in perfect harmony, contributing positively to the overall handling and stability. The rubber damped handlebar fixation reduces vibration and also allows for some adjustment with 2 different mounting positions. An hour meter is fitted as standard on the upper triple clamp on all SX models, keeping the rider informed of the number of hours spent tearing up the track and when the next service is due.

Brakes

High-tech Brembo brakes have always been standard equipment on all KTM motocross bikes. Combined with lightweight wave discs, the renowned system provides the highest level of braking efficiency, enabling you to out-brake the competition.

Fuel tank

The KTM 250 SX-F TROY LEE DESIGNS is fitted with lightweight polyethylene fuel tank. The shape of the fuel tank allows for slim ergonomics without compromise to the 7 liter (1.85 gal) fuel capacity. The filler cap has an inside thread that makes for easy and reliable closure.

Airbox

The airbox on the KTM 250 SX-F TROY LEE DESIGNS ensures optimal flow dynamics, and together with its intake snorkels, leads to maximum power and quick throttle response. Despite the obvious performance advantages, the design also offers maximum protection against soiling of the air filter. The large Twin-Air air filter is mounted on a cleverly designed stiff cage that minimizes incorrect installation. As found on previous models, filter maintenance is quick and easy and does not require tools - a standard, original feature from KTM.

Seat

A special blue seat cover with silicone strips improves the looks of the bike and provides optimal feel and grip for the rider. The seat is conveniently fixed to the bike using one long, lateral screw, making it secure and easy to handle.

Handlebar

The KTM 250 SX-F TROY LEE DESIGNS is fitted with a high-strength aluminum tapered handlebar, made by NEKEN. The handlebar is fixed in rubber damped mountings, which allow for two different positions. The handlebars come standard with an ODI vulcanized grip on the right side and a comfortable ODI lock-on grip, which does not require any wire or glue, on the left.

Footpegs

Sophisticated 'no-dirt' footpegs prevent clogging of the footpeg pivot, even when digging in deep ruts. Looking for a higher riding position? Then just mount the footpegs of the MY2019 EXC models, which are 6 mm higher than the SX versions

Decals

Offering a fast and aggressive look the inlay graphics perfectly replicate the race machines of the US-based TLD race team.

Battery

All SX-F models feature a capable, super lightweight 2 Ah Lithium-Ion starter battery, ensuring quick and effective starting of the engine, especially in cold weather conditions. The voltage regulator and condenser, as well as all the electrical components are packaged in a common area below the seat, making the entire system compact and reliable.

Traction Control

TRACTION CONTROL is a highly beneficial feature that guarantees more efficient traction and better control of the bike when accelerating on wet or slippery hard pack surfaces. It can be activated by the handlebar map switch during riding.

Launch Control

By pushing both buttons on the map switch, the rider can activate LAUNCH CONTROL, which ensures a more efficient launch out of the start gate. It reduces the maximum engine speed for the very first moment of the start to give better control. The EFI control lamp mounted on the upper triple clamps flashes when the function is active.