Model Description


All it takes is one hard, fast rip into a loamy berm to know that the
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.

ELECTRIC START
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.

START STRONG
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!

PERFORMANCE
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.

SELECTABLE MAPS
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
ABSOLUTE CONTROL
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.

ERGONOMICS
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.

MASS CENTRALISATION
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
TRACTION
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.

STABILITY
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.

MAINTAINING MOMENTUM
ENERGY ABSORPTION
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.

GROUND CLEARANCE
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.

CONSISTENCY
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.

Finance Calculator

Model Specification


  • Engine

    Engine Type

    Single cylinder, 2-stroke

    Displacement

    124.8 cc

    Starter

    Electric starter

    Transmission

    6 speed

    Clutch

    Wet multi-disc DS clutch, Brembo hydraulics

    ABS System

    Engine Management System

  • Dimensions

    Bore

    54 mm

    Stroke

    54.5 mm

    Ground Clearance (unloaded)

    359 mm

    Seat Height

    958 mm

    Weight (No Fuel)

    92.4 kg

  • Frame

    Frame

    Central double-cradle-type 25CrMo4 steel

    Chain

    5/8 x 1/4

    Steering Head Angle

    63.9 degrees

    Tank Capacity

    7.2 litres

  • Suspension

    Front Suspension

    WP XACT upside-down fork, 48 mm

    Rear Suspension

    WP XACT shock absorber with linkage

    Suspension Travel Front

    310 mm

    Suspension Travel Rear

    300 mm

  • Performance

    Brake System Front

    Disc brake 260 mm

    Brake System Rear

    Disc brake 220 mm

    Power

    Torque

  • Brakes

    Front Brake Disc Diameter

    Rear Brake Disc Diameter

Contact Us

Unit 6, Alphinbrook Court
Exeter, Devon.
EX2 8QR. United Kingdom

Tel: 01392 479 400

A little about Us

SP Motorcycles based in Exeter, Devon, we are proud of our no nonsense attitude to getting you the service you need. Whether it be help with buying your first bike or advice on how to get some extra power.

Finance available to UK residents of 18 or over and is subject to status. Indemnities may be required. Finance provided by Close Brothers Motor Finance. Close Brothers Motor Finance is a trading style of Close Brothers Limited (“CBL”), a subsidiary of Close Brothers Group plc. CBL is registered in England and Wales with company number 195626 and registered office at 10 Crown Place, London EC2A 4FT. Close Brothers Limited is authorised by the Prudential Regulation Authority and regulated by the Financial Conduct Authority and Prudential Regulation Authority. Firm reference number 124750.