At the heart of the 2017 KTM 50 SX cross - motocross motorcycle, KTM pairs a 49 cc (3 cu in) liquid-cooled single cylinder, two-stroke architecture with road-focused gearing. Internal engine geometry specifies a bore and stroke of 39.5 x 40.0 mm (1.6 x 1.6 inches) with a 12.5:1 compression ratio.
On the scales, the 50 SX measures 41.5 kg (91 lbs) dry. Rider ergonomics and chassis geometry center around a 684 mm (26.9 in) seat height — giving shorter riders and urban commuters confident flat-foot reach at traffic stops, combined with a 1,032 mm (40.6 in) wheelbase engineered for quick, flickable steering geometry. The 2.3-liter (0.6 US gal) fuel tank supports practical everyday commuting and weekend road stints.
Within MotoLibrary's KTM archive, this model family spans 19 indexed model years from 2006 to 2025, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.
Standover Height
684 mm (26.9 in)
Engine
Displacement49.0 ccm (2.99 cubic inches)
Engine TypeSingle cylinder, two-stroke
Engine DetailsReed intake.
Compression12.5:1
Bore x Stroke39.5 x 40.0 mm (1.6 x 1.6 inches)
Valves/Cylinder1
Fuel SystemCarburettor. Mikuni TMX
Fuel ControlDouble Overhead Cams/Twin Cam (DOHC)
IgnitionSeletra 2p D36
LubricationMixture oil lubrication
CoolingLiquid
Transmission
Gearbox1-speed
Final DriveChain (final drive)
ClutchCentrifugal clutch
Driveline415, Non-sealed chain
Chain Size420
Chassis
Frame TypeCentral-tube frame with double-cradle
Rake24.0°
Front SuspensionWP upside-down Ø 35 mm
Front Travel205 mm (8.1 inches)
Rear SuspensionWP shock absorber
Rear Travel185 mm (7.3 inches)
Wheelbase1032 mm (40.6 inches)
Ground Clearance252 mm (9.9 inches)
Wheels & Brakes
Front Tyre60/100-12
Rear Tyre2.75-10
Front BrakesSingle disc. Four-piston calipers.
Front Brake Ø160 mm (6.3 inches)
Rear BrakesSingle disc. Two-piston calipers.
Rear Brake Ø160 mm (6.3 inches)
WheelsWire spoked
Dimensions & Weight
Dry Weight41.5 kg (91.5 pounds)
Seat Height684 mm (26.9 inches) If adjustable, lowest setting.
Fuel Capacity2.30 litres (0.61 US gallons)
Oil Capacity0.75 litres (0.79 US quarts) transmission oil
Service & Fluids
Engine Oil2-stroke synthetic motorcycle oil (API TC / JASO FC/FD)
Use this page to compare this motorcycle by its real specifications, not only by model name. Focus on the details that affect fit, comfort, handling, range and ownership.
Seat Height
Check the seat height against your inseam and riding posture before choosing a motorcycle.
Weight
Compare weight carefully because it affects low-speed handling, parking and confidence.
Fuel Capacity
Fuel capacity helps estimate touring range and how often you may need to stop.
Brakes
Brake setup is worth comparing if you ride in traffic, mountains or with a passenger.
Suspension
Suspension details can matter for comfort, road feel and long-distance riding.
Transmission
Transmission and final drive affect maintenance, smoothness and everyday usability.
