Motocross Bikes
1999KTM SX 125
33 fields on record
The 1999 KTM SX 125 is a lightweight two-stroke enduro bike designed for amateur and intermediate off-road riders seeking agile handling and responsive performance. Its compact 91kg frame and 125cc single-cylinder engine deliver excellent maneuverability on technical terrain, making it ideal for motocross and trail riding. The bike is best known for KTM's reliable engineering and accessible entry point into competitive off-road riding.
- Capacity
- 125.0 ccm
- Engine
- Single, two-stroke
- Gearbox
- 6-speed
- Dry weight
- 91.0 kg
- Seat height
- 925 mm
- Power
- 15.0 HP (11.0 kW)
How it rides
Editorial estimate from the spec sheet - not lab tested- Best for
- Built as a lightweight motocross-style enduro machine for trail riding, motocross tracks, and technical off-road terrain rather than road use.
- Built for
- A raw, high-revving two-stroke that rewards aggressive, momentum-based riding with sharp handling and explosive acceleration on tap.
- Not ideal for
- Not a good fit for riders wanting a comfortable commuter, a passenger-friendly bike, or long-distance road touring capability.
Scores are derived from the spec sheet using the same model across every bike, so they compare like for like.
Will it fit you?
Worked out in your browser - nothing is sent to usEngine
- Capacity
- 125.0 ccm
- Power
- 15.0 HP (11.0 kW)
- Engine type
- Single, two-stroke
- Power/weight ratio
- 0.1648 HP/kg (dry)
- Bore x stroke
- 54.0 x 54.5 mm
- Cooling system
- Liquid
- Fuel system
- Carburettor
- Starting
- Kick
- Ignition
- Kokusan digital 2K-1
- Lubrication system
- Mixture oil lubrication 1:40
- Torque
- Not on record - add it
Transmission
- Gearbox
- 6-speed
- Transmission type
- Manual
- Final drive
- Chain
- Clutch
- Wet multi-disc clutch, operated hydraulically
Dimensions & weight
- Wheelbase
- 1461 mm
- Seat height
- 925 mm
- Dry weight
- 91.0 kg
- Fuel capacity
- 7.50 litres
- Ground clearance
- 390 mm
Chassis & suspension
- Frame
- Chromium molybdenum
- Front suspension
- WP-USD 48/26 MA/PA
- Rear suspension
- WP-PDS-DA shock absorber
- Front wheel travel
- 300 mm
- Rear wheel travel
- 335 mm
- Rake (fork angle)
- 24.0°
- Trail
- 63 mm
Brakes & wheels
- Front brakes
- Single disc
- Front brakes diameter
- 260 mm
- Rear brakes
- Single disc
- Rear brakes diameter
- 220 mm
- Front tyre
- 80/100-21
- Rear tyre
- 100/90-19
Specs last verified against published sources: .
Compiled from manufacturer documentation and user contributions, corrected on an ongoing basis. Spotted something wrong? Tell us.
Rider Reviews
Common questions
What is the engine size of the KTM SX 125?
The 1999 KTM SX 125 has a Capacity of 125.0 ccm (7.63 cubic inches).
What engine power does the KTM SX 125 have?
The 1999 KTM SX 125 has a Power of 15.0 HP (11.0 kW).
How many gears does the KTM SX 125 have?
The 1999 KTM SX 125 has a Gearbox of 6-speed.
How much does the KTM SX 125 weigh?
The 1999 KTM SX 125 has a Dry weight of 91.0 kg (200.6 pounds).
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