Motocross Bikes

2025KTM 50 SX

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The 2025 KTM 50 SX is a lightweight minibike designed for young and beginner riders entering the sport of motocross. Powered by a 49cc two-stroke engine with automatic transmission, it delivers sharp acceleration and easy handling on dirt tracks. Known for its aggressive styling and responsive WP suspension, the 50 SX excels as an entry-level cross machine that builds fundamental riding skills.

Capacity: 49.9 ccm
Engine: Single, two-stroke
Gearbox: 1-speed
Dry weight: 43.5 kg
Seat height: 653 mm
Power: 5.4 HP (4.0 kW)

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What’s new for the 2025 KTM 50 SX

vs the 2024

Spec	2024	2025
Rear suspension	XACT WP PDS mono shock	XACT WP mono shock

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

Off-road & trail80%

Cornering60%

City riding5%

Daily riding5%

Touring5%

Two-up0%

Track55%

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?

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Your height

Inseam (optional)

Units

At 653mm, a rider of 68.9" with a 31" (estimated) inseam will reach the ground with both feet flat on the 2025 KTM 50 SX, with a cramped knee angle of around 55 degrees and an upright riding position.

Assumes about 30mm of suspension sag once seated. This is an approximation from category-typical geometry, not a measurement of this bike or of you - sit on one before you buy.

More bikes at 750 mm or under — Short Kings →

Find bikes that fit your height →

Full specifications

Engine

Capacity: 49.9 ccm
Power: 5.4 HP (4.0 kW)
Engine type: Single, two-stroke
Power/weight ratio: 0.1241 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 EMS
Lubrication system: Mixture oil lubrication

Transmission

Gearbox: 1-speed
Transmission type: Automatic
Final drive: Chain
Clutch: Centrifugal

Dimensions & weight

Wheelbase: 1026 mm
Seat height: 653 mm
Dry weight: 43.5 kg
Fuel capacity: 2.30 litres
Ground clearance: 233 mm

Chassis & suspension

Frame: Chrome-molybdenum steel central-tube
Front suspension: XACT 35 WP Upside-Down fork, Ø 35 mm
Rear suspension: XACT WP mono shock
Front wheel travel: 200 mm
Rear wheel travel: 190 mm
Rake (fork angle): 24.0°
Trail: 90 mm

Brakes & wheels

Front brakes: Single disc
Front brakes diameter: 160 mm
Rear brakes: Single disc
Rear brakes diameter: 160 mm
Front tyre: 60/100-12
Rear tyre: 2.75-10

Other

Color options: White/orange/black/purple
Comments: Intended for children 4-10 years old.

Specs last verified against published sources: October 2026.

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	2022	2025	2027
Capacity	49 cc	49 cc	49 cc	49 cc	50 cc	50 cc
Dry weight	39 kg	40 kg	42 kg	42 kg	44 kg	44 kg
Seat height	650 mm	684 mm	684 mm	665 mm	653 mm	653 mm
Fuel capacity	1.8 L	2.3 L	2.3 L	2.3 L	2.3 L	2.3 L