Motocross Bikes
2020KTM 50 SX
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The 2020 KTM 50 SX is a youth motocross bike for young children starting to race. Its liquid-cooled 49cc two-stroke single drives through a single-speed automatic clutch and chain, and a kit can restrict its power for beginners. A 684 mm seat, 41.5 kg dry weight and 2.3-litre tank are sized for small riders.
- Capacity
- 49.0 ccm
- Engine
- Single, two-stroke
- Gearbox
- 1-speed
- Dry weight
- 41.5 kg
- Seat height
- 684 mm
- Power
- 5.4 HP (4.0 kW)
Other years
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
How it rides
Editorial estimate from the spec sheet - not lab tested- Best for
- It exists purely to teach a child the fundamentals of balance, throttle control, and off-road riding in a safe, low-powered package.
- Built for
- It behaves like a purpose-built miniature dirt bike, docile and forgiving with an automatic single-speed gearbox that removes clutch and shifting complexity so a child can focus on riding.
- Not ideal for
- It is not suitable for adults, taller teens, road use, touring, or anyone seeking real speed or highway 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
- 49.0 ccm
- Power
- 5.4 HP (4.0 kW)
- Engine type
- Single, two-stroke
- Power/weight ratio
- 0.1301 HP/kg (dry)
- Bore x stroke
- 39.5 x 40.0 mm
- Compression
- 12.5:1
- Cooling system
- Liquid
- Fuel system
- Carburettor
- Starting
- Kick
- Ignition
- Seletra 2p D36
- Lubrication system
- Mixture oil lubrication
Transmission
- Gearbox
- 1-speed
- Transmission type
- Manual
- Final drive
- Chain
- Clutch
- Centrifugal clutch
Dimensions & weight
- Wheelbase
- 1032 mm
- Seat height
- 684 mm
- Dry weight
- 41.5 kg
- Fuel capacity
- 2.30 litres
- Ground clearance
- 252 mm
Chassis & suspension
- Frame
- Central-tube frame with double-cradle
- Front suspension
- WP upside-down Ø 35 mm
- Rear suspension
- WP shock absorber
- Front wheel travel
- 205 mm
- Rear wheel travel
- 185 mm
- Rake (fork angle)
- 24.0°
- Trail
- 90 mm
Brakes & wheels
- Front brakes
- Single disc. Four-piston calipers.
- Front brakes diameter
- 160 mm
- Rear brakes
- Single disc. Two-piston calipers.
- Rear brakes diameter
- 160 mm
- Front tyre
- 60/100-12
- Rear tyre
- 2.75-10
Other
- Color options
- Orange/white/black
- Comments
- The engine power can be restricted to 5.5 hp with a kit.
Specs last verified against published sources: .
Compiled from manufacturer documentation and user contributions, corrected on an ongoing basis. Spotted something wrong? Tell us.
What changed, year to year
Differences highlighted| Specification | 2006 | 2011 | 2017 | 2020 | 2022 | 2027 |
|---|---|---|---|---|---|---|
| Capacity | 49 cc | 49 cc | 49 cc | 49 cc | 49 cc | 50 cc |
| Dry weight | 39 kg | 40 kg | 42 kg | 42 kg | 42 kg | 44 kg |
| Seat height | 650 mm | 684 mm | 684 mm | 684 mm | 665 mm | 653 mm |
| Fuel capacity | 1.8 L | 2.3 L | 2.3 L | 2.3 L | 2.3 L | 2.3 L |
Illustrative - generated automatically by diffing the year records already on file, not a manufacturer-published changelog.
Rider Reviews
Common questions
What is the engine size of the KTM 50 SX?
The 2020 KTM 50 SX has a Capacity of 49.0 ccm (2.99 cubic inches).
What engine power does the KTM 50 SX have?
The 2020 KTM 50 SX has a Power of 5.4 HP (4.0 kW).
How many gears does the KTM 50 SX have?
The 2020 KTM 50 SX has a Gearbox of 1-speed.
How much does the KTM 50 SX weigh?
The 2020 KTM 50 SX has a Dry weight of 41.5 kg (91.5 pounds).
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