KTM 125 SX 2027

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 option allows riders to adjust high- and low-speed settings in a matter of seconds. The forks on the front end are also easily modified thanks to hand-adjustable clickers on the bottom of the fork shoe and top cap.

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.

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 don’t sweat it. All you do is press the starter button and you blast off again to take the flag. This is the reality on the KTM SX models. Thanks to a 12,8V 2 Ah lithium ion battery placed under the rider’s seat, a high-quality starter and pickup and super robust design, the only thing you’ll be kicking – is ass.

The KTM SX and SX-F range is engineered and designed to provide riders with easy-to-access service parts, as well as suspension adjustability. This permits faster trackside and off-season maintenance, as well as simplifying motocross for novice riders without pit crews.

Give your KTM 125 SX a more bite with a 125 Factory Performance Kit. Comprising of upgraded engine parts, a Factory expansion chamber, and special engine mapping, it provides a 2.5 hp increase while saving 15% of weight over the standard exhaust parts.

With EFI comes great rideability. Along with the electronic fuel injection is an electronic 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!

Designed to churn out torque, the KTM 125 SX is set to continue its dominance in its class with unrelenting forward momentum. The overall engine weight is only 17.86 kg and carries 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 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.

Get ready for a full-on berm assault. The KTM SX and SX-F machines feature revised frame updates developed with input from KTM Factory Racing. For starters, the area around the rear shock mount is streamlined, with optimized engine mounts and cut-outs for improved chassis flex. The front area of the frame features optimized wall thickness with updated engine mounts.

Tank shrouds using bi-compound plastics channel air towards the radiators more efficiently, while a concise fuel tank roll makes for a tighter, more secure fitment, reducing the chance of frame scrubbing and dramatically improving durability. All this works alongside the specially developed rider triangle to provide unmatched knee contact and gripping surfaces – especially when standing on the pegs.

Let’s get the technical parts out of the way first; the 48 mm WP XACT AER forks fitted to the 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 has settings which not only compliment the frame and rear linkage, but ensures stellar performance at all levels. Speaking of settings, these are easily adjusted via a single air pressure pre-load valve, as well as easy-access click adjusters for compression and rebound. Additionally, the WP air pump needed to adjust the fork’s air pressure is provided as standard in the buy-pack.

Keeping things in check at the rear, the WP XACT rear shock uses settings directly from the KTM Factory Racing Teams. The frame and shock geometry mean more ground clearance at the linkage, making it less susceptible to bottoming out. Small diameter linkage bolts save weight, while optimal linkage seals refine rear shock response and advanced damping characteristics.

The KTM Motocross range has a special rear brake pedal adding additional stiffness, bending resistance and braking feel to the overall package. At the other end, a forged steering head connection and CNC-milled triple clamps, make for the perfect alignment of the fork tubes. This precise geometry of the fork clamps ensures highly responsive and smooth fork action – not to mention unwavering stability when charging across ruts and onto the podium.

Getting power hooked into the dirt is a tough job. However, hours of research and testing have led the KTM Motocross range to the Dunlop GEOMAX MX34. Providing unmatched stability and control at the highest level, the rubber features a rigid carcass and compound that improves damping and absorption, maintaining performance up to 30% longer than previous models. Progressive Cornering Block Technology also improves grip in the berms, while the rear pattern has a tall and wide center block for desirable traction and control everywhere else. Lastly, this unique block arrangement works to dispel mud buildup, ensuring traction in even the muddiest of track conditions.

Count on a durable chain guide and chain guard and minimize the chances of hooking on external objects – especially in extremely muddy terrain while reducing dirt build-up around the swingarm and rear sprocket. The modified fixing points and routing of the wiring harness result in less prone to wear and damage.

Besides the expertly crafted, hydro-formed, laser-cut, and robot-welded frame being engineered to provide exceptional rider feedback and straight-line stability, the chassis 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. Good thing then that the shock absorber geometry on the KTM SX and SX-F machines gives decent ground clearance for the linkage, with the topology-optimized die-cast footpegs being less susceptible to hooking on deep ruts, and take-offs when scrubbing.

This motorcycle comes with a Premium Manufacturer’s Warranty. Riders enjoy up to 1 year of coverage and experience the thrill of offroad riding with added peace of mind. To keep the warranty valid, always follow the guidelines outlined in your motorcycle’s Owner’s Manual, including using the bike as intended and completing all scheduled services at an authorized KTM dealer. The standard manufacturer’s warranty conditions, as specified in the delivery certificate, also remain applicable. More information and details on how to benefit from this offer can be found on the KTM warranty page. Valid from Model Year 2027 onwards for all offroad motorcycles as well as the 450 SMR.

The KTM 125 SX continues to set the benchmark in the highly competitive 125 cc class. Lightweight, agile, and built with a true READY TO RACE attitude, it delivers the performance required to fight for championships at the highest level. Ricardo Bauer proved exactly that in 2026, claiming both the FIM Junior Motocross World Championship and the EMX125 European Championship at just 15 years of age.