Quick Links
Find Us
Contact Us
Book a Service
Book a Test Ride
KTM
Call Us
Find Us
Call
Menu

Contact

Close
Contact
Tyre Safety Month
Free Winter Health Check
Tyre Tread Depth Gauge
Free Comprehensive Vehicle Health Check Video
Back
You are here:
KTM 125 SX
New Bike Offers
Make an Enquiry
Value My Bike

KTM 125 SX 

The KTM 125 SX is a high-performance two-stroke motocross machine crafted for riders seeking a powerful, lightweight weapon for competitive riding. With full READY-TO-RACE pedigree and fuel-injection technology, it delivers exhilarating performance in a compact, agile package that excites and rewards ambitious racers.​​

 Performance & Power Under the slim plastic is a 124.8 cc liquid-cooled, two-stroke single-cylinder engine with electronic fuel injection via a 39 mm throttle body and an advanced powervalve system. This rev-happy unit is paired with a six-speed gearbox and a wet multi-disc clutch actuated by Brembo hydraulic system, enabling sharp throttle response and seamless gear changes. Electric start and selectable engine maps add modern convenience and versatility. Its ultralight engine (just 17.9 kg) delivers accessible yet raucous two-stroke power, making it superb for refining throttle and clutch skills.
Control & Comfort Built on a chromoly steel central-cradle frame with a lightweight, reinforced polyamide subframe, the 125 SX weighs just over 92 kg wet. Its suspension includes a 48 mm WP XACT AER front fork providing 310 mm of travel and a WP XACT rear shock with 300 mm, all featuring tool-free adjustment for rapid setup. Braking comes from high-spec Brembo discs—260 mm front and 220 mm rear—mounted on a 21-inch front and 19-inch rear wheel setup, offering sharp stopping power and responsive handling.
Versatility & Style Sporting authentic Factory Racing graphics and clean, ergonomic bodywork, the 125 SX mirrors its full-size siblings with bold aesthetic and functional design. Features such as electric start, selectable engine maps (for tuning throttle response to terrain), and modern chassis updates from factory racing enrich usability and performance. Its nimble nature and low overall weight make it equally suited for competitive race settings, advanced training environments, or intense club track use where agility and precision matter most.
SPECIFICATION

PRICE

On The Road Price From £8,699​

ENGINE & TRANSMISSION

​

​Design​1-CYLINDER, 2-STROKE ENGINE
​Displacement124.8 CM³
​Transmission6-SPEED
​Fuel-mixture generation ​KEIHIN EFI, THROTTLE BODY 39 MM
​EMSVITESCO TECHNOLOGIES EMS 
​Clutch primary drive teeth​73
​Primary drive ​23:73
​​Clutch​WET, MULTI-DISC DS CLUTCH, BREMBO HYDRAULICS
Clutch Type DS MULTI-DISC WET CLUTCH
Clutch operation BREMBO HYDRAULICS 
​Engine cylinder ​SINGLE CYLINDER 
​Engine stroke​2-STROKE

CHASSIS

Frame DesignCENTRAL-DOUBLE-CRADLE-TYPE 25CRM04 STEEL
Front Brake DISC BRAKE
Rear Brake ​DISC BRAKE
​Rear subframe design​ALUMINIUM-REINFORCED POLYAMIDE
​Chain520, NON-SEALED
​Front Suspension​WP XACT-USD (AER) 0 48 MM 
Rear SuspensionWP XACT MONOSHOCK WITH LINKAGE 
​Suspension travel (front) 310 MM
​Suspension travel (rear) 
300 MM 
​Front suspension type ​WP XACT 
​Front suspension adjustment ​COMPRESSION (HIGH AND LOW SPEED) REBOUND
​Rear suspension setting COMPRESSION AND REBOUND ADJUSTABLE 

DIMENSIONS & WEIGHTS

​​​

​Seat height 958 MM
​Ground clearance 359 MM
​Tank capacity (approx.)7.2 L

FUEL CONSUMPTION

   ​

STANDARD EQUIPMENT

     

OPTIONAL EQUIPMENT

    

OPTIONAL ACCESSORIES

Title
BOOK A TEST RIDE
Title
CONFIGURE
Title
RESERVE
ACCESSORIES
ACCESSORIES Upgrade your ride with our range of quality motorcycle accessories. From luggage and protection to performance parts, everything is designed to fit perfectly and perform on every journey. Discover More
CLOTHING
CLOTHING Stay safe and stylish with our motorcycle clothing range. Helmets, jackets, gloves, and boots offer comfort, protection, and style for every type of rider. Discover More
VALUE MY BIKE
VALUE MY BIKE Get a fast, free valuation for your motorcycle. Simply enter your details to receive a competitive offer with no obligation to sell. Discover More