There are very few sounds that can't be beaten. The crack of a soda can on a blistering hot day. The ping of the perfectly executed golf shot. And the scream of a 125 cc 2-stroke charging down a long straightaway. The 2025 KTM 125 SX takes its leads directly from the Factory Racing team and puts them to work like nothing else. Like the sound it makes, it cannot be beaten.
The scream of a 125 cc 2-stroke charging down a long straightaway is one of life's true pleasures, and the 2025 KTM 125 SX at Lings KTM delivers that thrill like nothing else. Taking its cues directly from the KTM Factory Racing team, this machine is engineered to be unbeatable in its class.
At the heart of the 2025 KTM 125 SX is a powerful 124.8 cm³, 1-cylinder, 2-stroke engine that weighs a mere 17.86 kg.1 This lightweight powerhouse is designed to churn out relentless torque and impressive horsepower figures, retaining its typical high-revving character while providing grunt where it matters most.2 A major technological leap for the 2-stroke SX range is the Electronic Fuel Injection (EFI).3 This Keihin EFI system, combined with a reed valve case design and electronic power valve, ensures smooth, more usable power throughout the rev range, eliminating fiddly jetting setups.4 An electric starter, powered by a robust 12.8V 2 Ah lithium-ion battery, means instant restarts even in the heat of a race.5 Riders can also choose between two engine maps via a map select switch: Map 1 (White Map) offers a linear, predictable power delivery ideal for hard-packed dirt, while Map 2 (Green Map) is tuned for loose, thick, sandy conditions with a richer mix.
The chassis receives significant updates for 2025, derived directly from Factory Racing efforts.7 The central double-cradle-type 25CrMo4 steel frame features a reworked rear shock mount area and updated engine mounts with cut-outs, resulting in improved chassis flex, better cornering behavior, and a 300g weight saving.8 The WP XACT AER 48mm upside-down forks and WP XACT monoshock with linkage have been re-tuned for 2025, offering improved response and easy, tool-free adjustability for both high and low-speed compression, as well as rebound.9 Lightweight and strong black anodized D.I.D rims are fitted with race-tested Dunlop MX34 tyres, featuring new carcass and rubber compounds for improved damping, absorption, and up to 30% longer performance, along with enhanced traction. Braking is handled by powerful Brembo disc brakes, with a 260mm front and 220mm rear disc for exceptional stopping power.10 Ergonomically, new tank shrouds with bi-compound plastics improve radiator airflow and cooling, while a new fuel tank roll protects against scrubbing and enhances durability.11 An upgraded rear brake pedal adds stiffness and improved feel, completing a machine crafted for ultimate race performance.
