KTM 125 SX 2020

Produktinfo

KICKSTART YOUR RACING CAREER

The KTM 125 SX is the most compact and lightweight of the full-size bikes and delivers a confidence-inspiring ride like no other. A lightweight chassis teams up with the most competitive 125cc 2-stroke engine in its class, delivering superior agility and power to fulfil the demands of any young adrenaline seeker. This 2-stroke screamer is the ultimate entry point into the pro ranks and a sure-fire way to add to the trophy collection.

Motor og eksos

Motor og Eksos

KTM 2-strokes have been tearing up MX tracks for decades and are undoubtedly the fastest on the track today. Thanks to years of ongoing development, these engines are the benchmark in performance and technology, with the perfect combination of power, weight and control. For 2020, small, but important refinements have been made, resulting in improved power delivery and reliability and through its melodic high-RPM screams, KTM125 SX continues to deliver thrilling high-performance harmonics.

TRANSMISSION

The KTM 125 SX is fitted with a robust 6-speed transmission. The gear ratios, which featured improvements and reinforcements, were carried over from the predecessor. The gearbox features a new drive shaft which uses a screw for pinion fixation and diaphragm spring instead of a circlip, ensuring safer pinion fixation. Another highlight of the 125 […]

IGNITION

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

EXHAUST

When it comes to power delivery and performance, the exhaust developed specifically for this bike plays a key role and packs a punch that is hard to beat. In addition, its special shape provides slimmer ergonomics while still operating safely within the noise limits for racing.

ENGINE

The KTM 125 SX engine is undoubtedly once again the most competitive and powerful engine in its class. With an outstanding power-to-weight ratio, low cost and overall simplicity, it is clear that 2-strokes will continue to have a successful future at KTM. The compact and durable 17.2 kg engine was developed using the latest KTM […]

CYLINDER

At the heart of the 125 cc engine is a cylinder with a 54 mm bore. It features an improved power valve unit with a sophisticated mechanism designed for the lateral support exhaust ports. The exhaust port layout increases engine performance, while the upper contour of the exhaust port has been machined to ensure more […]

CRANKCASES AND ENGINE COVERS

The lightweight engine cases are manufactured using a high pressure die-cast production process, keeping wall thickness to a minimum while retaining strength and durability. The design allows for a high crankshaft position which is located near to the center of gravity, resulting in optimal mass centralization and easier rideability. The engine body is extremely compact, […]

COOLING

Maintaining the optimal engine temperature is crucial to ensuring consistent horsepower throughout the ride. The KTM 125 SX features radiators which are mounted 12 mm lower than the predecessors. This lowers the center of gravity and matches the design of the new shrouds perfectly in order to achieve perfect ergonomics. By using CFD technology (computational […]

CARBURETOR

The KTM 125 SX is fitted with a MIKUNI TMX 38 mm flat slide carburetor featuring settings that were adapted to suit the new airbox developed in 2019. For 2020, reworked reeds for intake reed block provide further improvements in function, sealing and reliability, ensuring the whole system is always providing smooth, controllable power throughout […]

Chassi

Chassi

To cater for the highly energized riding style of a 125cc 2-stroke rider, KTM developed a chassis that delivers on their demanding expectations. The lightweight, high-tech steel frame is designed to respond instantly to rider input and provide accurate rider feedback. The flex characteristics help the bike to soak up those big hits while also delivering excellent agility and high-speed stability. For 2020, the suspension features improved damping characteristics. The reworked settings offer a slightly softer, more comfortable feel that, together with the frame, allows the rider to be 100% in charge of the ride.

WHEELS

KTM uses lightweight, CNC-machined hubs and high-end Excel rims on all SX models, guaranteeing maximum stability and minimum weight. The aluminum spoke nipples feature a design that conveniently reduces the frequency with which the spokes need to be tightened. The wheels are fitted with the latest DUNLOP GEOMAX MX 3S tires, delivering maximum grip and […]

TRIPLE CLAMP

All KTM SX models feature top quality, CNC-machined triple clamps which have become a KTM trademark. The triple clamp has a precisely calculated stiffness and offset (22 mm offset for all models) to match the flex characteristics of the frame and fork. The result is a front end that all works in perfect harmony, contributing […]

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 […]

REAR SUSPENSION

All KTM SX models feature 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 […]

FUEL TANK

All models in the KTM SX range are fitted with lightweight polyethylene fuel tanks. The shape of the fuel tank allows for slim ergonomics without compromise to the 7 liter fuel capacity. The filler cap has an inside thread that makes for easy and reliable closure.

FRONT SUSPENSION

All full-size KTM SX models are 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 […]

FRAME

The frame and subframe on the KTM 125 SX caters for the aggressive riding styles associated with 125 cc racing. The frame itself is professionally crafted from hydroformed chromium molybdenum steel tubes that are robot welded, ensuring the highest levels of consistent quality. The stiffness has been precisely tailored for the most dynamic handling, and […]

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.

AIRBOX

The airbox on the KTM 125 SX 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 […]

Ergonomi og komfort

Ergonomi og komfort

Momentum is crucial when laying down fast laps on a 125cc. The ability to shift your weight quickly and easily to move in harmony with the motorcycle is key to maximizing flow. KTM focused extensively on the optimal ergonomics for high-level performance, ensuring a riding position that offers the best control and, with the option of several handlebar positions, can be adjusted to suit every rider and condition. The way a rider interacts with the bodywork, seat, footpegs and handlebars achieves balance and control. For this reason, no compromises were made in these important areas and only the best quality products and designs were used. Sitting on the 2020 KTM 125 SX gives the rider a definite sense of control and this is immediately confirmed the moment he hits the track.

SEAT

All KTM SX models feature a seat that perfectly matches the range’s dynamic performance-oriented ergonomics. The seat cover features silicone strips that provide better feel and grip for the rider. The seat is conveniently fixed to the bike using one long, lateral screw, making it safe and easy to handle.

HANDLEBAR

All full-size KTM SX models are equipped with the same 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 […]

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 KTM 2018 EXC models, which are 6 mm higher than the SX versions.

Bodywork og dekaler

Bodywork og dekaler

125 cc riders are renowned for riding with the most aggressive body language. Young, determined athletes riding with exaggerated style, pushing themselves and their machines to the limit. This was a critical consideration when developing the bodywork of the KTM 125 SX and was factored into the entire SX range. By using input from KTM factory riders, KTM R&D as well as Kiska Design, the bodywork of the KTM 125 SX achieves complete harmony between rider and bike. The main goal was to provide the perfect contact points for the rider, allowing him to move as freely as his spirit demands, with the control to match his intentions. The bodywork is full of intelligent design elements, like the I-beam structure on the front and rear fenders, which guarantee maximum stability with the lowest possible weight.

DECALS

The 2019 SX models feature the latest in-mold graphics, matching the new bodywork perfectly. They have a fast and aggressive style that screams READY TO RACE, leaving no doubt as to the bikes’ high-performance intentions.

Programvare og elektronikk

Programvare og elektronikk

Absolute performance purity is the name of the game when it comes to the KTM 125 SX. Undiluted 2-stroke simplicity with an hour meter to keep a check on how long you’ve been shredding and an optional rev counter to assist with perfect setup.

Tekniske detaljer

TECH DETAILS

Engine
Design
1-cylinder, 2-stroke engine
Displacement
124.8 cm³
Bore
54 mm
Stroke
54.5 mm
Starter
Kickstarter
Transmission
6-speed
Clutch
Multi-plate clutch, Brembo hydraulics
EMS
Kokusan
Chassis
Frame design
Central double-cradle-type 25CrMo4 steel
Front suspension
WP XACT-USD, Ø 48 mm
Rear suspension
WP XACT Monoshock with linkage
Suspension travel (front)
310 mm
Suspension travel (rear)
300 mm
Front brake
Disc brake
Rear brake
Disc brake
Front brake disc diameter
260 mm
Rear brake disc diameter
220 mm
Chain
5/8 x 1/4″
Steering head angle
63.9 °