The 125 SX has long since established itself as the undisputed top dog above all in junior race series and as a springboard to the professional leagues. Powered by a high-performance 2-stroke engine with exhaust control system and 6-speed transmission, the 125 SX has been further improved for the 2015 model year, ensuring it will maintain its popularity with young champions in future.
Standard Features May Include:
The engine on the 125 SX 2015 has been upgraded with an optimised ignition curve in order to achieve more effective combustion for better power development and optimum rideability.
LINKAGE / SHOCK ABSORBER
The revamped damping system for MY 2015 features a new linkage with optimised geometry. The flatter progression with a higher initial rate ensures greater stability and lowers the rear end. In addition, the new design saves another 40 grams of weight. The fully adjustable WP 5018 shock absorber has been completely retuned to suit the new linkage.
The fully adjustable upside-down fork from WP Suspension has been perfectly tuned to the new rear wheel damping system and the new 22 mm front axle (formerly 26 mm) for MY 2015. The new axle provides a better feel for the front wheel and also saves a further 40 grams. The new fork stubs now feature an offset of 33 mm instead of 35 mm, which together with increased trail deliver greater ride stability. Furthermore, they accommodate newly developed, 50 gram lighter fork protectors.
High-tech brakes from Brembo have always been standard equipment on KTM offroad bikes and, together with the lightweight wave brake discs, they are the measure of all things in terms of brake technology. As the best brakes in the motocross class, they remain unchanged for MY 2015.
The wheels fitted for MY 2015 feature black coated, high-end Excel rims with lightweight, CNC-machined hubs and spokes with lightweight aluminium nipples, allowing highest levels of stability to be achieved, while keeping weight to a minimum. New Dunlop Geomax MX 52 tyres were developed in collaboration with the KTM USA factory team and offer perfect traction with top performance. The new rear sprockets save 50 grams in unsprung mass.
2015 KTM 125 SX Base
Model Name125 SX
Generic Type (Primary)Off-Road
Engine Type1-cylinder 2-stroke engine, water-cooled, with reed intake and exhaust control
Displacement124.8 cm³ (7.616 cu in)
Bore54 mm (2.13 in)
Stroke54.5 mm (2.146 in)
Gearbox6-gear, claw shifted
Reduction Ratio, Primary23:73
Reduction Ratio, Secondary13:50
ClutchWet multi-disc clutch / Brembo hydraulics
IgnitionContactless, controlled, fully electronic ignition system with digital ignition timing adjustment, type Kokusan
Frame TypeCentral tube frame made of chrome molybdenum steel tubing
ForkWP Suspension Up Side Down 4860 MXMA 4CS
Shock AbsorberWP Suspension 5018 BAVP DCC
Front Suspension300 mm (11.81 in)
Rear Suspension317 mm (12.48 in)
Brake System TypeDisc brakes, brake calipers on floating bearings
Brake Disc Diameter, Front260 mm (10.24 in)
Brake Disc Diameter, Rear220 mm (8.66 in)
Sprocket Chain520 X-ring
Wheelbase1,480±10 mm (58.27±0.39 in)
Ground Clearance395 mm (15.55 in)
Seat Height, Unladen992 mm (39.06 in)
Fuel Capacity7.5 l Unleaded premium fuel (98 octane), mixed with 2-stroke engine oil (1:40)