125 SX – 2023
2023 KTM 125 SX is a serious contender in the 125 cc race. Not only has
the ‘Ring-ting-ting’ been given a fuel-injected revival, but the entire
motorcycle also benefits from class-leading developments at every end.
Boasting accolades such as being the leader in 2-stroke motocross
innovation in the modern era, the 2023 KTM 125 SX simply slays the rest
of the 125 cc class. All you need do is prod the starter, blip the
throttle and let rip.
BEFORE THE GATE
EASY SUSPENSION ADJUSTMENT
Get dialed in! The 2023 KTM SX range boasts totally tool-free suspension setup at both ends. Thanks to an all-new shock absorber design featuring hand-adjustable dual compression control, it allows riders to adjust high- and low-speed settings in a matter of seconds. On the front end, the forks are also easily adjusted thanks to a single air pressure preload valve, as well as through easy access click adjusters for compression and rebound. We’ll even throw the air pump in as standard.
ELECTRONIC FUEL INJECTION
Pre-mix gets a remix across the 2-stroke KTM SX range, with Electronic Fuel Injection setting the standard. Now there’s no more fiddly jetting setup pre-race, And thanks to the all-new Keihin EFI and reed valve case design, you can be guaranteed of laying down optimal power at any altitude, all of the time.
Picture this; You’re 7 laps into an absolute ripper of a race. You miss your line and end up stalling in a deep rut. But you don’t sweat it. All you do is press the starter button and you blast off again to take the final flag. This is the reality on the 2023 KTM 125 SX. Thanks to a 12,8V 2 Ah lithium ion battery is placed under the rider’s seat, a new high-quality stator & pickup and super robust design, the only thing you’ll be kicking – is ass.
EFI + POWER VALVE
With EFI comes great rideability. Along with the electronic fuel injection, a new power valve has also been fitted to the KTM 125 SX, allowing for more usable power throughout the rev range. Smoother power means better traction. Better traction means holeshot heaven!
Designed to churn out more torque than any 125 cc 2-stroke engine to ever come before it, the 2023 KTM 125 SX is set to continue its dominance in its class with unrelenting forward momentum. With an overall engine weight of only 17.86 kg and impressive horsepower figures, this lightweight powerplant retains its typical high-revving character, while laying down the grunt where it matters most.
Once again slicing into the 125 cc class with the leading edge of technology, the 2023 KTM 125 SX features a map select switch allowing the racer to switch between 2 engine maps.
CALM UNDER FIRE
No matter how gnarly the track is, you’ll stay in complete control thanks to an all-new frame design that has not only been engineered for longitudinal rigidity but also repositions rotating mass closer to the center of gravity. A new shock mounting also provides improved anti-squat behavior to better traction out of corners, while the footpeg mounting position has moved inwards for less risk of hooking up in deep ruts or when scrubbing jumps.
The 2023 KTM SX and SX-F range feature an entirely new and improved rider triangle, providing improved knee contact – especially when standing on the pegs – with improved gripping surfaces all around. New plastics work to expel mud buildup in wet, muddy conditions, with a new, flatter seat profile and high grip seat cover providing exceptional rider movement and control. The polyamide reinforced aluminum subframe further enhances rider feel and feedback.
With a major emphasis placed on mass centralisation, the 2023 KTM 125 SX engine is designed to centralise rotating mass for optimal operation with the chassis. This results in a lighter, more agile handling feel, which together with more torque and smoother power delivery, make it the most competitive 125 cc motocrosser yet.
HIT THE BIG STUFF
Ready to rip your arms out of the sockets? Together with the benefits of mass centralization and overall reduced weight, the anti-squat behavior of the chassis is significantly improved by changing the backbone of the steel frame concept. In layman’s terms, the 2023 KTM 125 SX gets its power down perfectly when tearing out of corners.
WP XACT FORK
48mm air type WP XACT front fork with a split damping function provides all the confidence you need to attack the track. New hydrostops in the fork legs improve bottoming-out resistance and account for less rebound when attacking big jumps, bumps, and thumps. Redesigned fork protection rings also increase protection against dirt, making them as reliable as they are awesome.
The 2023 KTM 125 SX is rock-solid at any speed thanks to a repositioned and forged steering head connection and CNC milled triple clamps. Made from high-grade aluminum, these feature optimally tuned steering stem stiffness, perfect alignment of the fork tubes, and precise geometry of the fork clamps to ensure highly responsive and smooth fork action – not to mention unwavering stability when charging across ruts and onto the podium.
Besides the expertly crafted, hydro-formed, laser-cut, and robot-welded frame being engineered to provide exceptional rider feedback and straight-line stability, it consists of specifically calculated parameters of longitudinal and torsional flex. This means the frame acts as a “shock absorber” of sorts, making for a less harsh ride, resulting in less rider fatigue over many hard laps.
No one enjoys a bad hook-up. Luckily, the all-new frame and shock absorber geometry on the 2023 KTM 125 SX improve ground clearance of the linkage, with all-new topology optimized die-cast footpegs that are less susceptible to hooking on deep ruts, and take-offs when scrubbing.
A new WP XACT shock absorber provides unmatched consistency lap after lap, thanks to low-friction SKF linkage seals and advanced damping characteristics for unsurpassed traction and energy absorption.
Single cylinder, 2-stroke
Wet multi-disc DS clutch, Brembo hydraulics
Engine Management System
Ground Clearance (unloaded)
Weight (No Fuel)
Central double-cradle-type 25CrMo4 steel
5/8 x 1/4
Steering Head Angle
WP XACT upside-down fork, 48 mm
WP XACT shock absorber with linkage
Suspension Travel Front
Suspension Travel Rear
Brake System Front
Disc brake 260 mm
Brake System Rear
Disc brake 220 mm
Front Brake Disc Diameter
Rear Brake Disc Diameter
5 based on votes
125 SX - 2023
Available in Stock