KTM 125 SX

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 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 2025 KTM 125 SX. Thanks to a 12,8V 2 Ah lithium ion battery is placed under the rider's seat, a high-quality stator & pickup and super robust design, the only thing you'll be kicking - is ass.

EASY SUSPENSION ADJUSTMENT
As always, the suspension boasts an easy tool-free setup at both ends, ensuring you chase down the podium in total control. On the rear, a hand-adjustable dual compression control allows riders to adjust high- and low-speed settings in a matter of seconds. The forks on the front end are also easily adjusted thanks to hand-adjustable clickers on the bottom of the fork shoe and top cap.

EFI + POWER VALVE
With EFI comes great rideability. Along with the electronic fuel injection and a power valve on 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 torque the 2025 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 2025 KTM 125 SX features a map select switch allowing the racer to switch between 2 engine maps. The White Map - or Map 1 - provides a linear, predictable power delivery ideally suited to attack hard-packed dirt with a leaner air-fuel mixture. Alternatively, the Green Map - Mapping 2 - is tuned for loose, thick sandy conditions with a richer mix.

WP XACT FORK
Let's get the technical parts out of the way first; the 48 mm WP XACT AER forks fitted to the 2025 KTM SX and SX-F line-up features a capsulated air spring and pressurized oil chamber for progressive and consistent damping, while oil and air bypasses reduce pressure peaks. In combination with the mid-valve damping system, all this provides exceptional feedback and rider comfort. The fork also boasts new settings, which not only compliment the updated frame and rear linkage, but ensures stellar p

WP XACT SHOCK
Keeping things in check at the rear, the WP XACT rear shock has also undergone some changes for 2025 using settings directly from the KTM Factory Racing Teams The improved frame and shock geometry mean more ground clearance at the linkage, making it less susceptible to bottoming out. While we're on the topic, smaller diameter linkage bolts save weight, while new linkage seals refine rear shock response and advanced damping characteristics.

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.

ABSOLUTE CONTROL
Get ready for a full-on berm assault. The 2025 KTM SX and SX-F machines have received major frame updates directly from Factory Racing efforts. For starters, the frame area around the rear shock mount has been updated and made more streamlined, with new engine mounts and cut-outs for improved chassis flex. The front area of the frame is also updated. with a different wall thickness than the previous model year, with renewed engine mounts. This adds up to a 300g weight saving and improved flex fo

2023 SX Range

Explore this vehicle in more detail with our handy video guide. We’ll talk you through its main features, show you some of the highlights of the bike and explain why it could be the right fit for you.

The information in this video was correct at the time of filming. We have made every effort to ensure this video is an accurate representation of the bike above. However, please contact the branch for full details.