2016 KTM 125 SX


Highlights The engine of the 125 SX has been known to be the most powerful and most competitive engine of the class. But it was time to give a new push to the segment and set a clear statement, that the two-stroke technology is going to have a successful future due to its outstanding power-to-weight ratio, low cost and simplicity. The newly developed 125cc engine for 2016 features a completely new architecture with the latest KTM engineering know-how and the most advanced technology in the class. The result is that it produces better power all over the rev range while being more compact and 4.4 pounds lighter.

Combine the all-new engine with the new state-of-the-art chassis that is shared with the 4-Stroke SX-F line, and you have a better handling 125 SX that will set a new benchmark in the class.


  • New 125 SX engine is more compact, is 4.4 pounds lighter and has more power for class dominance
  • New cylinder with revised ports and newly designed power valve unit with a sophisticated mechanism for the lateral exhaust ports gives a massive performance increase over the entire range
  • A new piston is optimized for maximum reliability with the new cylinder layout
  • Lighter crankshaft is optimally balanced for minimum vibrations
  • All-new die-cast engine cases raise the crankshaft and clutch shaft, centralizing mass and improving handling
  • New 6-Speed transmission provides the same gear ratios as before but is lighter and narrower
  • New “No Dirt” shift lever prevents dirt from fouling the lever joint to ensure proper shifting in any condition
  • New exhaust pipe has been tuned for the 125SX specifically to get maximum power output from the new engine

  • New lighter Chromoly steel frame provides higher torsional rigidity with less longitudinal stiffness resulting in improved handling and energy absorption
  • New smaller, lighter subframe design made with new aluminum profiles
  • New lighter swingarm features a revised internal structure to match the new frame characteristics
  • New lighter “ No Dirt” footpeg design that provides a larger surface area and features a “scraper” to reduce dirt build-up in the hinge
  • New CNC machined upper triple clamp featuring a rubber damping system for the new Neken handlebar and ODI lock-on grips
  • The advanced WP 4CS (Four Chamber System) Fork has been specifically designed for Motocross and features revised damping settings optimized for the new chassis
  • New generation WP shock has been developed in conjunction with the new frame and swingarm architecture including a new linkage/pullrod system
  • Super lightweight Galfer Wave rotors, CNC machined hubs, high-end Excel rims fitted with Dunlop GEOMAX MX32 tires are standard equipment
  • New airbox and airfilter design offers maximum protection for the engine while ensuring maximum airflow and providing quick “no tools” airfilter changes
  • New ergonomics and bodywork centralize mass, improve handling and rider comfort

Engine Type: Single Cylinder, 2-Stroke
Displacement: 124.8 cc
Bore / Stroke: 54.0 / 54.5 mm
Starter: Kickstarter
Transmission: 6 Gears
Fuel System: Keihin PWK 38S AG Carburetor
Lubrication: Premix 40:1
Primary Ratio: 23:73
Final Drive: 13:50
Cooling: Liquid Cooling
Clutch: Wet Multi-Disc Clutch, Brembo Hydraulics
Ignition: Kokusan
Frame: Central Double-Cradle Type 25CrMo4 Steel
Subframe: Aluminum
Handlebar: Neken, Aluminum Ø 28/22mm
Front Suspension: WP Suspension USD 4860 MXMA 4CS
Rear Suspension: WP Monoshock 5018 BAVP DCC with Linkage
Suspension Travel Front/Rear: 300 mm/11.81 in; 300 mm/11.81 in
Front/Rear Brakes: Disc Brake 260 mm/10.24 in; 220 mm/8.66 in
Front/Rear Rims: 1.60x 21, 2.15 x 19 Excel
Front/Rear Tires: 80/100-21”; 100/90-19” Dunlop MX32
Chain: 5/8 x 1/4 in
Silencer: Aluminum
Steering Head Angle: 26.1º
Triple Clamp Offset: 22 mm
Wheelbase: 1,485mm ± 10 mm / 58.5 ± 0.4 in
Ground Clearance: 375mm / 14.8 in
Seat Height: 960 mm / 37.8 in
Tank Capacity, Approx: 7.2L / 1.9 ga
Weight (without fuel), Approx: 89.2 kg / 196.7 lbs

First Look: 2016 U.S. KTM SX Models

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