What you see on the 2018.5 450 SX-F Factory Edition has made its way to KTM's new 2019 SX-F model lineup. Chassis, bodywork and engine changes all makeup just some of the new features on the 250 and 350 SX-F. Two-stroke lovers don't fret as the SX's receive their fair share of updates as well. Check out all of the 2019 KTM motocross model information below.

2019 HIGHLIGHTS

Improved engines with more efficient performance
Reworked frame with improved stiffness, longer subframe
New bodywork with improved ergonomics and better seat comfort
Improved radiators/cooling system
Improved suspension settings
Newly designed exhaust systems
New graphics and colors

CHASSIS

CHASSIS – Frame, bodywork, fuel tank, airbox, exhaus

FRAME

All SX models feature new high-tech and lightweight chrome-moly steel frames in various profiles including hydro-formed elements produced by WP Performance Systems with state-of-the-art robots. They have the proven geometries as before but due to a re-design in several areas they feature an optimized stiffness (longitudinal + 2%, torsional + 10%) compared to the predecessor versions which provides better feedback to the rider, more precise handling and improved stability. The laterally attached engine head stays (the connection between cylinder/head and frame) are now made in aluminum for all models (new for 250 SX) and contribute to precise cornering and a reduced vibration level. Newly designed frame guards feature a structured surface improving the grip and the right one also serves as heat protector for the muffler. On the 4-stroke frames three new brackets in the lower part of the frame allow the fixation of an optional composite skid plate offered in Power Parts, In the 250 SX frame the engine is raised by 1° around the swing arm pivot improving the handling and the grip of the front wheel.

The subframe is made of extra-light and stable aluminum profiles, which weighs less than 900gr. For better rear fender stability it is 40 mm longer than before.

NEW:

Reworked frames → improved stiffness, handling and straight line stability

4-strokes with new brackets for fixation of a skid plate → easy mount of an optional skid plate

250 SX with aluminum head stays → reduced weight

250 SX engine position raised by 1° → improved handling, better front wheel grip

40 mm longer subframe → improved rear fender stability

SWINGARM

All models are fitted with a reworked cast aluminum swingarm featuring a longer slot for the rear axle. This allows the adjustment of the rear wheel in a position up to 5 mm further back which gives the rider the option of gaining more straight line stability for fast tracks and whoops. The single-component casting process offers low weight and a perfect flex behavior.

NEW:

Longer rear axle slot → better straight line stability

BODYWORK

All factory riders were involved in shaping the new bodywork of the SX models together with the specialists from KTM R&D and Kiska Design. The results are all new plastics that provide perfect ergonomics and contact points for the rider, maximum freedom of movement and improved handling. In addition, the I-beam design for the front and rear fenders are prime examples of an intelligent design, which guarantees maximum stability at lowest weight through a well thought-out structure and mounting.

NEW:

New bodywork → better ergonomics, more freedom of movement, improved handling, new appearance

SEAT

A newly shaped seat provides improved ergonomics and better seat comfort. Due to newly developed silicone strips the seat cover provides better feel and grip. The fixation of the seat with one long, lateral screw is safe and easy to remove and install.

NEW:

Newly shaped seat → better ergonomics and comfort

AIRBOX

The new airbox has been completely reworked ensuring better airflow towards the engine for optimal performance and throttle response. In addition the new design offers maximum protection of the air filter against soiling. Together with new intake snorkels (except for 125/150cc) this leads to further improved engine performance. The large Twin-Air air filter is mounted on a stiff cage, which provides the fixation of the system at the same time. The simple design also minimizes incorrect installation of the filter and cage. The filter can be changed without tools in seconds, a standard, original feature by KTM.

NEW:

Reworked airbox and intake snorkels → maximum protection of the air filter against soiling, better airflow for optimal performance

FUEL TANK

All models of the SX range are fitted with newly designed lightweight polyethylene tanks improving the ergonomics with a capacity of approx. 1.85 gallons of fuel. The filler cap with an inside thread makes for easy and reliable closure. For the 4-stroke models the fuel pump assembly features an optimized internal routing of the hoses for improved reliability.

NEW:

New fuel tanks → improved ergonomics, 4-strokes with optimized fuel pump assembly

EXHAUST

The engineers put a lot of effort into developing completely reworked exhaust systems for all models. When it comes to improved power delivery and performance of the new bikes the new exhausts plays a key role and they are hard to beat by any accessory exhaust systems. In addition they provide the slimmer ergonomics while being safely within the noise limits for racing.

The four-strokes are fitted with new, model-specific header pipes showing a further advanced resonator version called FDH (Flow Design Header), which is a small chamber around the pipe. This is a unique standard feature, well integrated into the pipe, making the front part of the exhaust slimmer and providing better engine performance and reduced noise.
The 2-strokes shine with new exhaust pipes made by WP in an innovative 3D process which further improve the performance. The 250 SX pipe features reduced width and more ground clearance and due to the new shape, it is stronger against hits and deformation. In terms of performance, it allows a higher over-rev of the engine giving the 250 SX even livelier engine characteristics.

All models are fitted with new silencers featuring reworked internal designs individually developed for each model. The plastic holder of the 2-strokes mufflers is now replaced by lightweight, welded mounting brackets. In addition new perforated inner tubes work together with a new and lighter silencer packing for more efficient and more durable noise reduction. Weight reduction approx. 300gr.

The 4-stroke mufflers feature a new profile of the aluminium sleeve and a new end cap as well as a reworked internal design. A longer connecting pipe of the muffler moves the split between header pipe and muffler further in front. This improves the user-friendliness because the exhaust system can now be disassembled without removing the shock absorber before and allows better access to the shock.

NEW:

New 4-stroke header pipes with FDH resonator system, reworked 2-stroke pipes → improved performance

New mufflers for all models → optimal performance in conjunction with low noise level

CHASSIS – Wheels, brakes, handlebars, wiring harness, seat, cooling system, graphics

HANDLEBAR

All SX models are equipped with a tapered handlebar made of high-strength aluminum by NEKEN, which is fixed in rubber damped handlebar mountings allowing the handlebar to be mounted in two different positions. All models are all fitted with ODI volcanized grips on the right side while on the left side of the bar a comfortable ODI lock-on grip is mounted, which does not require any wire or glue to be fixed.

A reworked bar pad featuring a newly designed cover can be fixed easier to the handlebar.

NEW:

Reworked bar pad and cover → better look, improved fixation

HANDLEBAR MAP SWITCH

All four-stroke models are equipped with a multi-functional handlebar map switch, which features various functions:

Activation of the traction control

Activation of the launch control

Selection of an alternative power curve (standard <–> advanced),

The TRACTION CONTROL is a unique feature. With its new setting it guarantees even more efficient traction and better control of the bike when accelerating the bike especially on wet tracks. It can be activated by the handlebar map switch during riding. With a simple push of the two buttons at idle speed the rider can also activate the LAUNCH CONTROL which provides more efficient starts out of the gate by reducing the maximum engine speed for the very first moment of the start to give better control. Thanks to a reworked set-up the Launch Control now benefits automatically from the Traction Control during acceleration in order to reduce wheel spin for maximal possible traction. The EFI control lamp mounted on the upper triple clamps indicates when the function is active. In addition the map switch gives the rider the chance to select an alternative, more powerful map beside the standard configuration.

New:

Improved setting of traction and launch control → better traction, more efficient starts

WHEELS

The KTM wheels use lightweight, CNC machined hubs and high-end Excel rims guaranteeing maximum stability at minimum weight. For MY19 the aluminum nipples feature a reworked design in order to reduce the frequency of tightening the spokes.
The wheels are fitted with the latest MX tires from Dunlop (Geomax MX 3S).

NEW:

Improved nipple design → less maintenance

BATTERY & WIRING HARNESS

All SX-F engines are fitted with the proven electric starter – a unique KTM feature and a major benefit at all levels of motocross racing. A new and more capable, super lightweight 2 Ah Lithium-Ion starter battery provides even quicker starting of the engine especially at cold weather conditions and contributes to the low vehicle weight. A reworked packaging of the voltage regulator and condenser concentrate the electrical components in a common area below the seat and make the entire system even more reliable.

NEW:

Stronger and super light Lithium-Ion battery → safer starting

Reworked wiring harness and packaging → compact electrical system

GRAPHICS

New modern graphics highlight the new generation of cutting-edge KTM Motocross bikes. Still feature in-mold design.

NEW:

New most modern graphic design → Factory appearance

COOLING SYSTEM

All models feature newly designed radiators made by WP Performance Systems which are mounted 12mm lower than the predecessors. This lowers the center of gravity and in conjunction with a new radiator shape they match perfectly with the design of the new spoilers to make the bike narrower and easier to get forward on the bike. Thanks to CFD calculated liquid circulation and air ventilation the entire system was improved. Also a reworked coolant tube integrated in the frame triangle features 4 mm larger center tube increasing the cross section by 57%. This makes the coolant flow from the cylinder head to the radiators more efficient.

A sophisticated design of the new radiator guards integrated in the front part of the spoilers provides efficient protection for the new radiators in case of crashes.

NEW:

Newly designed radiators and optimized cooling system → more efficient cooling

BRAKES

High-tech Brembo brakes have always been standard equipment on KTM off-road bikes, and are combined with lightweight Wave discs.

MONOSHOCK

The DDC monoshock made by WP Performance Systems has been developed in conjunction with the entire frame and swingarm architecture, including the linkage system and the AER 48 forks. An updated main piston and new settings provide improved damping characteristics and match perfectly the reworked front fork set-up. Fully adjustable including high- and low speed compression you can set the shock to any track and riders preferences.

NEW:

WP monoshock with reworked main piston and settings for all models → confidence inspiring damping characteristics

FORKS

All models are fitted with the super-lightweight WP AER 48 front fork, a 48 mm USD air-sprung fork developed by WP Performance Systems in close collaboration with KTM. It is a split fork with separate functions for each fork leg. That means damping functions are on the right side, whereas the air spring is in the left. The left leg features a two-chamber system with a capsuled air cartridge to prevent loss of air pressure e.g. spring force. That means in case of a leaking outer seal the internal cartridge pressure keeps 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 air pump supplied with the bike is enough. The right fork leg integrates a damping cartridge to fit single damping leg requirements. Damping can be adjusted to the track conditions and the rider’s preferences (compression from top, rebound from bottom, 30 clicks each).
For MY19 new settings on the damping side provide better damping characteristics.

NEW:

WP AER 48 fork with reworked damping set-ups → improved damping characteristics

TRIPLE CLAMP

Top quality, CNC machined triple clamps have been something of a KTM trademark for years. The new models feature reworked and stiffer upper triple clamps (22mm off-set for all models) which feature an improved stiffness adapted to the reworked frame stiffness and the flex characteristics of the latest fork in order to improve the both handling and stability.
The rubber damped handlebar fixation reduces the vibration level and allows to fix the handlebar in 2 positions. In addition an hour meter is fitted at the upper triple clamp in order to keep the rider informed when maintenance should be performed.

NEW:

Redesigned upper triple clamps → improved handling and stability

WEIGHT

One target of the KTM engineers when developing the new SX models was a further weight reduction compared to the previous generation. The result is: the current SX models set a clear benchmark again, they are (by far) the lightest bikes in the competition.

GENERAL

All bikes come with a newly developed plug-in stand for the rear wheel made of injected plastic which at the same time serves as a spacer for the front wheel when tying down the bike for transport. This reduces high static pressure on the air cartridge and prevents the front fork from being compressed during transport.

NEW:

Dual purpose plug-in side stand also serving as spacer for the front fork → innovative solution

4-STROKE INTRODUCTION

KTM continues the powerhouse revolution with its range of world-beating 4-Stroke engines. The sheer power, rideability and performance of the KTM 4-stroke bike makes it difficult to beat in all classes. For the MY 2019 all models feature reworked engines and set a new benchmark again when it comes to performance, power delivery and rideability.

228088_SXF 250 MY19 Front-Right.jpg — 2019 KTM 250 SX-F

The new 250 SX-F has been the lightest and best-performing bike in its class and the new model will be another step forward. The new 250 SX-F is the right choice for both the amateur and professional riders, as it will remain a winning bike that will be hard to chase for its competitors. With a lot of improvements on the chassis and engine side, it is definitely faster than ever before.

250 SX-F ENGINE

The 250 SX-F engine is known to be the strongest engine in its engine class. And with updates on valve timing, exhaust, airbox and EMS the entire power pack produces even more torque and power across the entire rpm range up to 14,000 rpm. Its compact architecture contributes to an excellent mass centralization. This supports the easy rideability of the bike together with a low weight of only 57 lb, including the incredibly beneficial electric starter. In short, the combination of a compact engine layout and unrivaled power will make the new 250 SX-F once again an undisputed winner, it is easy to ride for both amateur and professional riders.

250 SX-F CYLINDER HEAD

The centerpiece of the compact DOHC (double overhead camshaft) engine is the cutting-edge cylinder head. It features two overhead camshafts which activate the titanium valves (intake 32.5mm, exhaust 26.5mm) via super-light finger followers with a hard DLC coating. The exhaust cam shaft features a new timing for improved power delivery.

NEW:

New exhaust cam shaft → improved power delivery

250 SX-F CYLINDER & PISTON

In the short cylinder that has a bore of 78mm, works a lightweight, forged bridged box-type piston made by CP. It features a unique piston crown shape adapted to the combustion chamber and stands out with its extra rigid structure, combined with a low weight. The compression ratio is at 14.4:1. Thanks to the low oscillating masses, the engine displays extremely lively characteristics.

250 SX-F CRANKSHAFT

The 250 SX-F’s has a rigid crankshaft which features a connecting rod with a plain big end bearing featuring two force-fitted bearing shells run directly on the crank pin. This design is a major prerequisite for the extremely high engine speed levels and the unrivalled maximum power of the 250cc engine. Not only that, it enhances the engine’s durability, allowing long crankshaft service intervals, which is a huge customer benefit in relation to time, effort and cost.

250 SX-F COUNTER BALANCE SHAFT

In order to balance the mass-forces the 250 SX-F engine uses a multifunctional counter balance shaft, which at the same time drives the water pump and timing chain.

250 SX-F ELECTRIC STARTER

The 250 SX-F is fitted with a unique electric starter as standard, which is well known as a clear advantage when it comes to crunch time in the heat of battle. A strong starter motor made by Mitsuba and the proven starter drive guarantees efficient and reliable starting.

250 SX-F ENGINE CASES AND COVERS

The design of the die-cast engine cases allowed for minimal weight and a very centralized shaft configuration. This makes the engine very short and compact, while contributing to an efficient centralization of masses. The engine covers feature a surface structure, which reduce the wear caused by the rider’s boots.

250 SX-F CLUTCH

A newly developed DS (diaphragm steel) clutch features a one-piece clutch basket combined with the primary gear made of high-strength billet steel. It guarantees unbeatable reliability and contributes to the narrow engine size due to its compact rivet-less design. It is fitted with extremely heat-resistant steel carrier friction discs which ensure a good disengagement of the clutch. These are pre-tensioned by means of a diaphragm spring, substantially reducing the operating force required to pull the clutch. The Brembo hydraulic system provides easy and precise modulation.

NEW:

Newly designed DS clutch → very compact and reliable clutch system

250 SX-F TRANSMISSION

The 250 SX-F uses a new 5-speed transmission made by PANKL RACING SYSTEMS ensuring the highest durability and reliability level. There was no need to change the gear ratios that are perfectly matched to the power delivery of the large displacement engine.

An advanced “NO DIRT” gear lever design prevents dirt from blocking the joint of the lever and guarantees safe activation of the transmission.

All four-stroke engines are fitted with a gear sensor giving the option of different engine characteristics for each gear.

NEW:

PANKL is the new manufacturer of the transmission → improved durability and reliability.

250 SX-F ENGINE MANAGEMENT SYSTEM

The state-of-the-art Keihin Engine Management System, with electronic fuel injection, features a new 44mm throttle body, which provides a spontaneous response and maximum performance thanks to its unique injector position. This guarantees excellent atomization of the fuel with the air on its way to the combustion chamber. In addition there are separate systems for cold start and idle adjustment. A reworked throttle cable mount allow for smoother routing of the cables and better access, an improved seal of the MAP sensor (MAP = Manifold-Absolute-Pressure) makes the system even more reliable.

The ECU features new maps adapted to the new exhaust and cylinder head and it regulates the unique traction and launch control. In addition it provides different maps for optimal power characteristics for each gear according to the information received by the gear sensor.

NEW:

Reworked throttle body → improved throttle cable routing and better reliability

New maps, optimized Launch and Traction control set-up → optimal performance, more efficient starts, better traction

CONCLUSION

Dominance in international Motocross and Supercross racing

Class-leading power, agile handling

Lowest weight in the 250 class

Electric starter for easy and effortless starts

High-level standard equipment

The success story of the 350 SX-F is certainly unrivaled. When KTM started to race with this model KTM factory rider “Tony” Cairoli managed to win the MX1 World Championship with just 350cc in comparison to the more common 450cc utilized by his rivals. Since then and again for MY19 the 350 SX-F has gained a lot of performance and torque providing almost as much power as a 450, but with the agility of a 250 – so the basic idea is easily summarized, and has been a concept with success from the start.

350 SX-F ENGINE

The engine of the 350 SX-F features a compact and very light (58.6 lb.) construction. Featuring a new clutch, improved transmission and a re-designed and lighter DOHC cylinder head the engine is stronger than ever before. Lightweight titanium valves and DLC coated finger followers allow for lively but also very strong engine characteristics. Fitted with the latest electronic fuel injection system and electric starter, it has an even wider usable speed range, improved performance and incredibly efficient rideability.

350 SX-F CYLINDER HEAD

The 350 SX-F has a reworked cylinder head design featuring the same architecture as before but it lost 200gr of weight. The two overhead camshafts with a friction-optimized super-fine surface, finger followers with a DLC coating are taken over as well as four lightweight titanium valves (intake 36.3mm, exhaust 29.1mm). The flow rate has been maximized for an optimal power band, with outstanding performance across the entire range, which ends at an engine speed of 13,400 rpm.

NEW:

Reworked cylinder head → reduced weight

350 SX-F CYLINDER & PISTON

In the short cylinder, with a bore of 88mm, is a forged bridged box-type piston made by CP. Its piston crown geometry is adapted perfectly to the high-compression combustion chamber and stands out with its extra rigid structure, combined with a low weight. The compression ratio is at 14:1. Thanks to the low oscillating masses, the engine offers extremely lively characteristics.

350 SX-F CRANKSHAFT

The 350 SX-F’s crankshaft features a stiff design and it utilizes a short connecting rod, contributing to the compact and light engine with a dynamic and efficient power delivery. A plain big end bearing features two force-fitted bearing shells run directly on the crank pin. This design is a major prerequisite for the extremely high engine speed levels and the unrivaled maximum power of the 350cc engine. Not only that, it enhances the engine’s durability, allowing long crankshaft service intervals – a customer benefit in respect of time, effort and cost.

350 SX-F COUNTER BALANCER SHAFT

In order to balance the mass-forces, the 350 SX-F engine uses a multifunctional counter balance shaft, which at the same time drives the water pump and timing chain.

350 SX-F ELECTRIC STARTER

The 350 SX-F is fitted with a unique electric starter as standard, which is well known as a clear advantage when it comes to crunch time in the heat of battle. A strong starter motor made by Mitsuba and the proven starter drive guarantees efficient and reliable starting.

350 SX-F CLUTCH

A newly developed DS (diaphragm steel) clutch features a one-piece clutch basket combined with the primary gear made of high-strength billet steel. It guarantees unbeatable reliability and contributes to the narrow engine size due to its compact rivet-less design. It is fitted with extremely heat-resistant steel carrier friction discs which ensure a good disengagement of the clutch. These are pre-tensioned by means of a diaphragm spring, substantially reducing the operating force required to pull the clutch. The Brembo hydraulic system provides easy and precise modulation.

NEW:

Newly designed DS clutch → very compact and reliable clutch system

350 SX-F TRANSMISSION

The 350 SX-F uses a new 5-speed transmission made by PANKL RACING SYSTEMS ensuring the highest durability and reliability level. There was no need to change the gear ratios that are perfectly matched to the power delivery of the large displacement engine.

An advanced “NO DIRT” gear lever design prevents dirt from blocking the joint of the lever and guarantees safe activation of the transmission.

All four-stroke engines are fitted with a gear sensor giving the option of different engine characteristics for each gear.

NEW:

PANKL is the new manufacturer of the transmission → improved durability and reliability.

350 SX-F ENGINE CASES AND COVERS

The design of the die-cast engine cases allowed for minimal weight and a very centralized shaft configuration. This makes the engine very short and compact, while contributing to an efficient centralization of masses. The engine covers feature a surface structure, which reduces the wear caused by the rider’s boots.

350 SX-F ENGINE MANAGEMENT SYSTEM

The state-of-the-art Keihin Engine Management System, with electronic fuel injection, features a new 44mm throttle body, which provides a spontaneous response and maximum performance thanks to its unique injector position. This guarantees excellent atomization of the fuel with the air on its way to the combustion chamber. In addition, there are separate systems for cold start and idle adjustment. A reworked throttle cable mount allows for smoother routing of the cables and better access, an improved seal of the MAP sensor (MAP = Manifold-Absolute-Pressure) makes the system even more reliable.

The ECU features new maps adapted to the new exhaust and cylinder head and it regulates the unique traction and launch control. In addition it provides different maps for optimal power characteristics for each gear according to the information received by the gear sensor.

NEW:

Reworked throttle body → improved throttle cable routing and better reliability

New maps, optimized Launch and Traction control set-up → optimal performance, more efficient starts, better traction

350 SX-F BENEFITS

Top-level performance with improved power delivery for less effort

250 agility with 450 power

Lowest weight

Electric starter for easy and effortless starts

High quality level “made in Austria”

If maximum power is required, there is no other way but the 450 SX-F. This model has proven itself in the highest league winning the AMA Supercross championship 2017 with Ryan Dungey and the MX World Championship with Tony Cairoli. For MY19 this machine with its SOHC (single overhead camshaft) engine takes the next step. Thanks to its newly designed and compact cylinder head the bike delivers even more explosive but controllable power and makes this bike the weapon of choice for the Super Cross and Motocross Factory teams. In conjunction with the all new chassis, the 450 SX-F shines with unparalleled handling and stability and it will be the fastest 450 Motocross bike KTM has ever built.

450 SX-F ENGINE

The successful powerhouse of the 450 SX-F has been reworked and features even more compact dimensions, further reduced weight to 59.5 lb. and a more efficient performance throughout the rev range. Fitted with a newly designed, extremely compact single overhead camshaft cylinder head and the latest electronic fuel injection, it is distinguished by unrivaled power and a highly efficient power delivery. And last but not least including the super-beneficial electric starter this model is the lightest 450 engine on the MX market.

450 SX-F CYLINDER HEAD

The 450 SX-F is fitted with a newly developed SOHC cylinder head which is much more compact, 15mm lower and 500gr lighter improving the mass centralization. The gas flow through the newly shaped ports is controlled by a new overhead camshaft which is now closer to the center of gravity improving the handling. It features an improved cam surface and a shorter valve timing for better responsiveness. It activates four ultra-lightweight titanium valves (intake 40mm, exhaust 33mm) via extremely rigid rocker arms, which are DLC coated on the intake side allowing engine speeds of up to 11,500rpm. New low-friction chain guides contribute to reduced friction. The new head configuration guarantees a more efficient power delivery and an unrivalled performance of the large displacement KTM engine.

NEW:

Newly developed SOHC cylinder head → weight reduced by 500gr, more compact design, better mass centralization

New camshaft with shorter valve timing and improved surface → improved responsiveness and reliability

Low-friction chain guide and DLC coating → high reliability, reduced friction

450 SX-F CYLINDER AND PISTON

In the short cylinder, featuring a bore of 95mm, is an extremely lightweight box-in-box type piston that delivers a major contribution to the engine’s low vibrations and engine-speed strength. The compression ratio is 12.75:1.

450 SX-F CRANKSHAFT

The 450 SX-F’s crankshaft is located in an ideal position close to the center of gravity contributing to an easy bike handling. It utilizes a short connecting rod, which contributes to an overall compact and light engine with a snappy power delivery, while a well-balanced inertia supports the traction and rideability. A plain big end bearing with two force-fitted bearing shells runs directly on the crank pin. The necessary oil feed for this bearing is ensured by the engine’s pressure lubrication. This design is a decisive customer benefit in terms of the crankshaft service interval, which can be lengthened due to the plain bearing.

450 SX-F COUNTER BALANCE SHAFT

The side mounted counter balance shaft at the same time drives the water pump. Thanks to the perfect mass balancing and this powerhouse’s low total oscillating masses, engine vibrations can be kept to a minimum even at the highest engine speeds.

450 SX-F ELECTRIC STARTER

Like all KTM 4-stroke motorcycles, the 450 SX-F is started with ease by pushing a button. Especially in the heat of a motocross battle, as demonstrated time and time again, an electric starter can become an invaluable advantage.

450 SX-F ENGINE CASES AND COVERS

The design of the die-cast engine cases allowed for minimal weight and a very centralized shaft configuration. This makes the engine very short and compact, while contributing to an efficient centralization of masses. The engine covers feature a surface structure, which reduces the wear caused by the rider’s boots.

450 SX-F CLUTCH

The 450 SX-F employs the KTM-developed DDS clutch (damped diaphragm steel) with a wear-free steel basket and extremely heat resistant clutch plates. This design is distinguished by employing a diaphragm spring instead of the usual coil springs, which makes for a considerably easier clutch action. The diaphragm spring also leaves sufficient space for a damping system integrated into the clutch hub, which benefits for both traction and durability.

The hydraulic Brembo clutch mechanism offers light operation and highly controllable modulation of the clutch.

450 SX-F TRANSMISSION

The 450 SX-F uses a new 5-speed transmission ensuring the highest durability and reliability level. There was no need to change the gear ratios that are perfectly matched to the power delivery of the large displacement engine.

An advanced “NO DIRT” gear lever design prevents dirt from blocking the joint of the lever and guarantees safe activation of the transmission.

All four-stroke engines are fitted with a gear sensor giving the option of different engine characteristics for each gear.

NEW:

450 SX-F ENGINE MANAGEMENT SYSTEM

The state-of-the-art Keihin Engine Management System, with electronic fuel injection, features a new 44mm throttle body, which provides a spontaneous response and maximum performance thanks to its unique injector position. This guarantees excellent atomization of the fuel with the air on its way to the combustion chamber. In addition there are separate systems for cold start and idle adjustment. A reworked throttle cable mount allows for smoother routing of the cables and better access, an improved seal of the MAP sensor (MAP = Manifold-Absolute-Pressure) makes the system even more reliable.

The ECU features new maps adapted to the new exhaust and cylinder head and it regulates the unique traction and launch control. In addition it provides different maps for optimal power characteristics for each gear according to the information received by the gear sensor.

NEW:

Reworked throttle body → improved throttle cable routing and better reliability

New maps, optimized Launch and Traction control set-up → optimal performance, more efficient starts, better traction

450 SX-F BENEFITS

Compact SOHC engine design for extreme power and torque

Robust 5-speed transmission

DDS hydraulic clutch, compact design and flawless clutch operation

Electric starter for easy and effortless starts

Efficient power delivery and class-leading performance

2-STROKE INTRODUCTION

KTM sets the benchmark in terms of 2-Stroke technology with its vast range of race winning motocross bikes. While many manufacturers may have turned their back on the development of the lighter weight range, KTM’s success in numerous off-road competitions with these motors, and especially for junior racing, is second to none. KTM provides a full-range of motorcycles with the intention of ensuring the junior can progress through the ranks with the same brand they are accustomed to from an early age. They are excellent alternatives for all those who search for an easy to ride motocross bike with an outstanding power-to-weight ratio and a less demanding technology compared to the 4-strokes. For MY 2019 all models feature all new chassis and lot of detail improvements making these bikes even faster than before.

227186_SX 125 MY19 90-Right.jpg — 2019 KTM 125 SX

The high performing and well-proven KTM 125 SX has been on the market at the front of the field for years. With an all new chassis powered by a lightweight, compact and high-performance 2-stroke engine, with a power valve and 6-speed gearbox fitted in a state-of-the-art chassis, the new KTM 125 SX remains a favorite among young champions and will be the benchmark again in the 125cc class.

125 SX ENGINE

The latest engine of the 125 SX is the most powerful and most competitive engine of the class and KTM sets a clear statement that two-stroke technology is going to have a successful future due to its outstanding power-to-weight ratio, low cost and simplicity. The 125cc engine was developed with the latest KTM engineering know-how and the most advanced technology in the class. The result is that it produces class-leading power across the rpm range, it is extremely compact and with 37.9 lb. total the lightest engine of its class. The benefit for the rider will be reflected in fast lap times due to easy rideability and an outstanding performance.

125 SX CYLINDER

Within the heart of the 125cc engine is a reworked cylinder that has a bore of 54mm which is fitted with a further improved power valve unit including a sophisticated mechanism for the lateral support exhaust ports. A new layout of the exhaust port increases the engine performance, in addition the upper contour of the exhaust port is machined now which guaranties more accurate port timing. Together with a two-component cylinder head, this is the key for an outstanding performance over the entire range.

NEW:

New cylinder with optimized exhaust port → improved and more constant performance

125 SX ENGINE CASES

The lightweight die-cast engine cases feature a high crankshaft position located close to the center of gravity, which results in optimal mass centralization for best rideability. In addition, the engine body is extremely compact and this contributes massively to the low engine weight. For MY19 the seat of kickstart intermediate gear has been reinforced for better reliability.

Thanks to a new clutch and a new clutch cover, the engine width is reduced by 10mm.

NEW:

Optimized seat of kickstart intermediate gear → improved reliability

New clutch cover → reduced engine width

125 SX CRANKSHAFT

The reliable crankshaft provides a stroke of 54.5mm and an excellent balancing guarantees minimum vibrations. The latest engine generation allows an increase of the displacement to 144cc just by replacing cylinder, piston and head without changing the crankshaft.

125 SX CLUTCH

A newly developed DS (diaphragm steel) clutch features a one-piece clutch basket combined with the primary gear made of high-strength billet steel. It guarantees unbeatable reliability and allows a reduction of the engine width by 10mm due to its compact rivet-less design. It is fitted with extremely heat-resistant steel carrier friction discs which ensure a good disengagement of the clutch. These are pre-tensioned by means of a diaphragm spring, substantially reducing the operating force required to pull the clutch. The Brembo hydraulic system provides easy and precise modulation.

NEW:

Newly designed DS clutch → very compact and reliable clutch system, reduced engine width

125 SX TRANSMISSION

The 125 SX is fitted with a new and robust 6-speed transmission which is now made by Pankl. The perfect gear ratios adapted to the 125cc power band are taken over from the predecessor, but all gear feature improvements and reinforcements. And thanks to the newly built PANKL transmission production plant in Austria the quality and reliability of the new gear box is at the highest level.

An advanced “NO DIRT” gear lever design prevents dirt from blocking the joint of the lever guaranteeing safe activation of the transmission.

NEW:

New transmission made by PANKL → highest quality and reliability

125 SX CARBURETOR

The 38mm flat slide carburetor provides smooth and controllable power delivery and guarantees optimal performance over the entire range. A new carburetor setting is adapted to the new airbox and exhaust design.

NEW:

Reworked carburetor setting adapted to the new airbox and exhaust system → improved throttle response and engine behavior

125 SX EXHAUST

The 125 SX is fitted with a new exhaust system featuring a newly designed exhaust pipe and the muffler. The pipe produced by WP with the latest 3-D stamping technology has an optimized shape and in conjunction with the reworked internal design of the silencer the power delivery and engine performance have been further improved. In addition the plastic fixing system of the muffler is replaced by a welded aluminum bracket reducing the weight of the muffler slightly.

NEW:

New exhaust pipe and muffler → improved power delivery and performance

New bracket of the muffler → reduced weight

125 SX BENEFITS

Top performance, maximum fun, low running costs

Amazing agility and easy handling

Ideal entry to top-level motocross

Hydraulic clutch

Best brakes in motocross

Lowest weight within the class

227187_SX 150 MY19 90-Right.jpg — 2019 KTM 150 SX

With the 150 SX the fun really does never end. With all the agility of a 125, but the power and torque to take the fight to the 250cc 4-strokes, this is a fun and lively bike for the 2-Stroke fan. The compact and lightweight engine producing class-leading torque and power is fitted in a completely reworked new chassis. With these developments, KTM offers an unbeatable and fast package that is certain to make the new 150 SX the ultimate competitor on the track.

150 SX ENGINE

The engine of the 150 SX was developed with the latest know-how and state-of-the-art technology. The result is that it produces class-leading power all over the rev range, it’s the lightest and most compact engine in its class. The benefit for the rider will be reflected in faster lap times due to easy rideability and high performance. This motorcycle shares many of its key components with the class-leading 125. The cylinder, head and piston unit can now also be fitted on a 125cc engine base converting it to a 150 SX without replacing the crankshaft.

150 SX CYLINDER

Within the heart of the 150cc engine is a compact cylinder that has a bore of 58mm which is fitted with a further improved power valve unit including a sophisticated mechanism for the lateral support exhaust ports. A new layout of the exhaust port increases the engine performance, in addition the upper contour of the exhaust port is machined now which guaranties more accurate port timing. Together with a two-component cylinder head, this is the key for an outstanding performance over the entire range.

NEW:

New cylinder with optimized exhaust port → improved and more constant performance

150 SX ENGINE CASES

The lightweight die-cast engine cases feature a high crankshaft position located close to the center of gravity, which results in optimal mass centralization for best rideability. In addition, the engine body is extremely compact and this contributes massively to the low engine weight. For MY19 the seat of kickstart intermediate gear has been reinforced for better reliability. Thanks to a new clutch the new clutch cover is lower reducing the engine width by 10mm.

NEW:

Optimized seat of kickstart intermediate gear → improved reliability

New clutch cover → reduced engine width

150 SX CLUTCH

A newly developed DS (diaphragm steel) clutch features a one-piece clutch basket combined with the primary gear made of high-strength billet steel. It guarantees unbeatable reliability and allows a reduction of the engine width by 10mm due to its compact rivet-less design. It is fitted with extremely heat-resistant steel carrier friction discs which ensure a good disengagement of the clutch. These are pre-tensioned by means of a diaphragm spring, substantially reducing the operating force required to pull the clutch. The Brembo hydraulic system provides easy and precise modulation.

NEW:

Newly designed DS clutch → very compact and reliable clutch system, reduced engine width

150 SX Carburetor

The 38mm flat slide carburetor provides smooth and controllable power delivery and guarantees optimal performance over the entire range. A new carburetor setting is adapted to the new airbox and exhaust design.

NEW:

Reworked carburetor setting adapted to the new airbox and exhaust system → improved throttle response and engine behavior

150 SX TRANSMISSION

The 150 SX is fitted with a new and robust 6-speed transmission which is now made by Pankl. The perfect gear ratios adapted to the 150cc power band are taken over from the predecessor, but with several improvements and reinforcements and thanks to the newly built transmission production plant the quality and reliability is at the highest level.

An advanced “NO DIRT” gear lever design prevents dirt from blocking the joint of the lever guaranteeing safe activation of the transmission.

NEW:

New transmission made by PANKL → highest quality and reliability

150 SX EXHAUST

The 150 SX is fitted with a new exhaust system featuring a newly designed exhaust pipe and the muffler. The pipe produced by WP with the latest 3-D stamping technology has an optimized shape and in conjunction with the reworked internal design of the silencer the power delivery and engine performance have been further improved. In addition the plastic fixing system of the muffler is replaced by a welded aluminum bracket reducing the weight of the muffler slightly.

NEW:

New exhaust pipe and muffler → improved power delivery and performance

New bracket of the muffler → reduced weight

150 SX BENEFITS

250cc 4-stroke rivaling performance, low maintenance costs

125 agility and handling

Never-ending fun

Hydraulic clutch

Best brakes in Motocross

The 250 SX features a high-performance two-stroke engine fitted in a state-of-the-art chassis. Designed with the entire know-how of the KTM R&D and motorsport department the 250 SX with its class-leading performance is the fastest than 250cc two-stroke in its class. With enough power to excel on all sorts of tracks and terrain, combined with an extremely lightweight chassis, the 250 SX has one of the best power-to-weight ratios in motocross. The unrivaled performance of the lightweight 2-stroke engine makes it a true contender against the more complex 4-strokes.

250 SX ENGINE

The engine of the 250 SX is known to be the most powerful and most competitive 2-stroke engine of the class. The new KTM 250 SX engine features a cylinder with twin-valve controlled power valve, a counter balance shaft for low engine vibrations, a 5-speed transmission and a hydraulically operated DDS clutch. Thanks to refinements of the cylinder and exhaust the 250cc power plant shines with outstanding performance and is the right choice for everybody who loves low purchasing and maintenance costs and the typical 2-stroke sound.

250 SX CYLINDER

The cylinder of the 250 SX with a bore of 66,4mm is fitted with a Twin-Valve power valve system which features a machined exhaust port for more precise function of the power valve improving the power delivery for MY19. The power characteristics can be changed within a few seconds thanks to two supplied springs allowing optimal settings to different tracks and rider’s preference. The lateral cylinder head brackets allow a more efficient fixation of the engine to the frame via 2 head stays reducing the vibration level which are now made of aluminum instead of steel.

NEW:

Machined exhaust port → higher precision of the power valve, improved power delivery

250 SX TRANSMISSION

The engine is fitted with a 5-speed gearbox with the optimal gear ratios for any kind of motocross racing. The so-called “NO DIRT” gear lever design prevents dirt from blocking the joint of the lever guaranteeing always safe activation of the transmission.

250 SX COUNTER BALANCE SHAFT

The engine is fitted with a lateral counter balance shaft in order to reduce the vibration level. This lowers the stress level for the rider making the ride more comfortable and enjoyable.

250 SX WATER PUMP

The engine features a reworked water pump casing in order to optimize the flow of the liquid for more efficient cooling.

NEW:

Reworked water pump → more efficient cooling

250 SX CLUTCH

The 250 SX employs the KTM-developed DDS clutch (damped diaphragm steel) with a wear-free steel basket and extremely heat resistant clutch plates. This design is distinguished by employing a diaphragm spring instead of the usual coil springs, which makes for a considerably easier clutch action. The diaphragm spring also leaves sufficient space for a damping system integrated into the clutch hub, which benefits both traction and durability.

The hydraulic Brembo clutch mechanism stands for light operation and highly controllable modulation of the clutch.

250 SX CARBURETOR

The 38mm flat slide carburetor provides smooth and controllable power delivery and guarantees optimal performance over the entire range. A new carburetor setting is adapted to the new airbox and exhaust design.

NEW:

Reworked carburetor setting adapted to the new airbox and exhaust system → improved throttle response and engine behavior

250 SX EXHAUST

The 250 SX is fitted with a new exhaust system featuring a newly designed exhaust pipe and the muffler. The pipe produced with the latest WP 3-D stamping technology allows for more ground clearance and features reduced width making the entire bike more compact. And in conjunction with the reworked internal design of the silencer the power delivery and engine performance have been further improved. In addition the plastic fixing system of the muffler is replaced by welded aluminum brackets reducing the weight of the muffler slightly.

NEW:

New exhaust pipe and muffler → more compact dimensions, improved power delivery and performance

New brackets of the muffler → reduced weight

250 SX BENEFITS

Unbeatable power-to-weight ratio

Low weight and excellent agility

Counter balance shaft for minimal vibrations

DDS hydraulic clutch system for effortless and flawless clutch action

Best brakes in motocross

GENERAL

All bikes come with a newly developed plug-in stand for the rear wheel made of injected plastic which at the same time serves as a spacer for the front wheel when tying down the bike for transport. This reduces high static pressure on the air cartridge and prevents the front fork from being compressed during transport.

NEW:

Dual purpose plug-in side stand also serving as spacer for the front fork → innovative solution

The riders of the junior class are not beginners. These are future champions fighting for victory, no matter if it is the AMA Amateur National Title or Junior Motocross World Championship. The 2018 KTM 85 SX is a completely new weapon for class supremacy. An all-new model from the ground up, the 85 SX boasts an engine with more power and ridability across the entire rev range and a chassis that allows the rider to use every bit of that power. There is no 85cc machine that is more READY TO RACE than the 2018 KTM 85 SX.

2019 KTM 85 SX Highlights

NEW engine in 2018 with improved power and torque over the entire rev range is 1.5 pounds lighter.
New orange frame and graphics to match the full-size SX bikes
Cylinder is designed around an all-new power valve system that is adjustable and increases torque and controllability.
Crankshaft is lighter than before while having more inertia for better torque. Optimized balancing reduces vibrations.
DS (Diaphragm Spring) clutch is more compact with better performance than a conventional coil spring design.
Crankcases are more compact with a shaft arrangement that is close as possible to the center of gravity.
Chrom-moly steel frame is nearly a pound lighter with 7% more torsional rigidity and 25% less longitudinal stiffness for more agility and better bump absorption.
WP AER 43 front fork with a sophisticated air spring design and separate damping for easy adjustment to any track condition, rider weight or skill level.
WP PDS (Progressive Damping System) rear shock provides excellent bump absorption and stability.
Aluminum subframe is lighter and more compact for better mass centralization.
Cooling system features integrated crankcase cooling and two radiators for high performance. The newly designed system uses the shroud and grill to protect the radiator in a crash.
Sharp bodywork that is based on the full-sized SX models with the same contact points and overall feel for perfect ergonomics.
Airbox similar to the larger SX models allows for air filter changes in seconds without tools.
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.

2019 85 SX SPECIFICATIONS

Engine Type: Single Cylinder, 2-Stroke
Displacement: 84.9 cc
Bore / Stroke: 47 / 48.95 mm
Starter: Kickstarter
Transmission: 6 Gears
Fuel System: Keihin PWK 28
Lubrication: Premix 40:1
Primary Ratio: 20:64
Final Drive: 13:46
Cooling: Liquid Cooling
Clutch: Wet Multi-Disc DS Clutch, Formula Hydraulics
Ignition: Kokusan
Frame: Central Tube Frame, Chrome Molybdenum
Subframe: Aluminum
Handlebar: Tapered Aluminum Ø 28/22mm
Front Suspension: WP USD AER 43 Ø 43 mm
Rear Suspension: WP PDS Monoshock
Suspension Travel Front/Rear: 280 mm / 11 in; 305 mm / 12 in
Front/Rear Brakes: Disc Brake 240 mm / 210 mm
Front/Rear Rims: 1.40 x 17” / 1.60 x 14”
Front/Rear Tires: 70/100-17” / 90/100-14” MAXXIS
Chain: 1/2 x 5/16 in
Silencer: Aluminum
Steering Head Angle: 24º
Triple Clamp Offset: 14 mm
Wheelbase: 1,290 mm ± 10 mm / 50.8 in ± 0.4 in
Ground Clearance: 352 mm / 13.9 in
Seat Height: 855 mm / 33.7 in
Tank Capacity, Approx: 5.2 L / 1.4 gal
Weight (without fuel), Approx: 67 kg / 147.7 lbs

The 65 SX is a fully-fledged piece of racing kit for young pilots. This year’s top mini features revolutionary WP AER 35 front forks, cool graphics and detailed improvements that set the standard in terms of power, riding dynamics, equipment and craftsmanship. Further weight reduction from the new WP AER 35 fork make the 65 SX even sharper on the track. Like its larger counterparts, the 65 SX is truly READY TO RACE for its young competitors.

2019 KTM 65 SX Highlights:

New ODI grips for 2019
New fork guards
WP AER 35 air-sprung front fork is 1.7 pounds lighter and makes adjustments for the rider size and track easy
Sleek bodywork that provides excellent ergonomics for the ultimate in control
NEW graphics to match the full-size SX models and orange frame
The 65 SX benefits from cutting-edge 2-stroke technology and an easy to shift 6-speed transmission with a hydraulic clutch.
A WP PDS monoshock guarantees optimum damping characteristics and outstanding stability. The rear wheel travel is 270mm.
With adjustable compression and rebound, the suspension can be set up precisely for the rider and track in no time.
The 65 SX is fitted front and rear with massive four-piston calipers that grip lightweight Wave brake discs of 198mm front and 160mm rear diameter.
Like the big KTM factory racers, the 65 SX has super lightweight, black anodized, aluminum rims providing the highest strength.
MAXXIS knobby tires provide superb grip in any terrain.

2019 KTM 65 SX SPECIFICATIONS

Engine Type: Single Cylinder, 2-Stroke
Displacement: 64.9 cc
Bore / Stroke: 45.0 / 40.8 mm
Starter: Kickstarter
Transmission: 6 Gears
Fuel System: Mikuni TM 24-505
Lubrication: Premix 60:1
Primary Ratio: 23:75
Final Drive: 14:48
Cooling: Liquid Cooling
Clutch: Wet Multi-Disc Clutch, Formula Hydraulics
Ignition: AET Digital
Frame: Central Tube Frame, Chrome Molybdenum
Subframe: Aluminum
Handlebar: Renthal, Aluminum Ø 22mm
Front Suspension: WP AER 35 USD Ø 35mm
Rear Suspension: WP Monoshock
Suspension Travel Front/Rear: 217 mm / 8.5 in; 270 mm / 10.6 in
Front/Rear Brakes: Disc Brake 198 mm / 220 mm
Front/Rear Rims: 1.60 x 14” / 1.60 x 12”
Front/Rear Tires: 60/100-14” / 80/100-12”
Chain: 1/2 x 1/4 in
Silencer: Aluminum
Steering Head Angle: 25.5º
Triple Clamp Offset: 22 mm
Wheelbase: 1,137 mm ± 10 mm / 44.8 in ± 0.4 in
Ground Clearance: 280 mm / 11 in
Seat Height: 750 mm / 29.5 in
Tank Capacity, Approx: 3.5 L / 0.92 gal
Weight (without fuel), Approx: 52.2 kg / 115.1 lbs

The 50 SX is a true READY TO RACE KTM for young MX riders. It is a genuine dirt bike that, like its bigger siblings, is produced with top-quality components. This makes the 50 SX the first choice as a stepping stone into the world of MX or for the first racing step on the ladder. With the youngster in mind this package has an engine that delivers steady, controllable power, incorporating an automatic clutch that allows the rider to concentrate on the track, not shifting. This year’s model features revolutionary WP AER 35 front forks, fully adjustable rear suspension, a new exhaust, ultra-cool graphics and detail improvements that make going fast fun.

2019 KTM 50 SX Highlights:

New fork guards
New ODI grips
New orange frame and graphics to match the full size SX bikes
WP AER 35 air-sprung fork is easily adjustable for different rider sizes as well as track conditions
Fully adjustable rear suspension to match the performance of the WP AER 35 fork
A 3-shaft engine design keeps the crankshaft close to the bike’s center of gravity for quick handling along with room for an optimized reed valve angle for maximum performance
Bodywork that mimics the full-size SX-F line that gives the 50 SX a slim profile for excellent ergonomics and handling
Front and rear hydraulic brakes by Formula combined with lightweight WAVE discs are powerful with feedback that gives control for any skill level
A centrifugal multi-disc automatic clutch provides manageable acceleration and can be adjusted to the track conditions in minutes without tools
Super lightweight, black anodized aluminum rims are matched to MAXXIS tires for maximum grip

2019 50 SX SPECIFICATIONS

Engine Type: Single Cylinder, 2-Stroke
Displacement: 49 cc
Bore/Stroke: 39.5/40.0 mm
Starter: Kickstarter
Transmission: Rigid 1-Stage Reduction Gear
Fuel System: Dell’Orto PHBG 19 BS
Lubrication: Premix 60:1
Primary Ratio: 33:61 Straight Cut Reduction Gear
Final Drive: 11:40
Cooling: Liquid Cooling
Clutch: Centrifugal Clutch (Adjustable)
Ignition: Selettra 2p D36
Frame: Central Tube Frame, Chrome Molybdenum
Subframe: Steel
Handlebar: Renthal, Aluminum Ø 22mm
Front Suspension: WP AER 35 USD Ø 35mm
Rear Suspension: WP Monoshock
Suspension Travel Front/Rear: 205 mm / 8.07 in; 185 mm / 7.28 in
Front/Rear Brakes: Disc Brake 160 mm / 160 mm
Front/Rear Rims: 1.50 x 12” / 1.60 x 10”
Front/Rear Tires: 60/100 x 12” / 2.75 x 10”
Chain: 1/2 x 3/16 in
Silencer: Aluminum
Steering Head Angle: 24.0º
Triple Clamp Offset: 22 mm
Wheelbase: 1,032mm ± 10 mm / 40.6 ± 0.4 in
Ground Clearance: 252mm / 9.92 in
Seat Height: 684 mm / 26.9 in
Tank Capacity, Approx: 2.3L / 0.61 gal
Weight (without fuel), Approx: 44.8 kg/ 90 lbs