Motocross Bikes
2020KTM 125 SX
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The 2020 KTM 125 SX is a lightweight motocross bike engineered for young and amateur riders seeking an accessible entry into competitive racing. Known for its responsive WP suspension package and electric start convenience, this machine delivers nimble handling and reliable performance on amateur racing circuits and training grounds.
- Capacity
- 124.8 ccm
- Engine
- Single, two-stroke
- Gearbox
- 6-speed
- Dry weight
- 87.8 kg
- Seat height
- 950 mm
- Power
- 15.0 HP (10.9 kW)
What’s new for the 2020 KTM 125 SX
vs the 2019| Spec | 2019 | 2020 |
|---|---|---|
| Front suspension | WP-USD, AER 48, Ø 48 mm | WP upside-down Ø 48 mm |
| Rear suspension | WP shock absorber with linkage | WP Monoshock |
| Front brakes | Single disc. Brake calipers on floating bearings | Single disc |
| Rear brakes | Single disc. Brake calipers on floating bearings | Single disc |
Other years
2003
2004
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2008
2009
2010
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2012
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2019
2020
2021
2022
2023
2025
2026
2027
How it rides
Editorial estimate from the spec sheet - not lab tested- Best for
- Built purely for closed-course motocross racing, it excels at jumps, berms, and rapid direction changes on dirt tracks rather than any street use.
- Built for
- Light, explosive, and razor-sharp in handling, it rewards aggressive riding with a peaky two-stroke power band and minimal weight to manage.
- Not ideal for
- It is not suitable for commuting, highway travel, passengers, or riders seeking comfort, storage, or a forgiving low-end power delivery.
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
- 124.8 ccm
- Power
- 15.0 HP (10.9 kW)
- Engine type
- Single, two-stroke
- Power/weight ratio
- 0.1708 HP/kg (dry)
- Bore x stroke
- 54.0 x 54.5 mm
- Cooling system
- Liquid
- Fuel system
- Injection
- Starting
- Electric
- Ignition
- Contactless, controlled, fully electronic ignition system with digital ignition timing adjustment, type Kokusan
- Lubrication system
- Wet sump
Transmission
- Gearbox
- 6-speed
- Transmission type
- Manual
- Final drive
- Chain
- Clutch
- Wet multi-disc clutch, mechanically actuated
Dimensions & weight
- Wheelbase
- 1489 mm
- Seat height
- 950 mm
- Dry weight
- 87.8 kg
- Fuel capacity
- 7.50 litres
- Ground clearance
- 375 mm
Chassis & suspension
- Frame
- Central double-cradle
- Front suspension
- WP upside-down Ø 48 mm
- Rear suspension
- WP Monoshock
- Front wheel travel
- 310 mm
- Rear wheel travel
- 150 mm
- Rake (fork angle)
- 26.1°
- Trail
- 120 mm
Brakes & wheels
- Front brakes
- Single disc
- Front brakes diameter
- 260 mm
- Rear brakes
- Single disc
- Rear brakes diameter
- 220 mm
- Front tyre
- 110-17
- Rear tyre
- 150-17
Other
- Color options
- White, Orange
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 | 2003 | 2009 | 2015 | 2020 | 2027 |
|---|---|---|---|---|---|
| Capacity | 125 cc | 125 cc | 125 cc | 125 cc | 125 cc |
| Dry weight | 94 kg | 91 kg | 91 kg | 88 kg | 92 kg |
| Seat height | 925 mm | 985 mm | 992 mm | 950 mm | 958 mm |
| Fuel capacity | 7.5 L | 8 L | 7.5 L | 7.5 L | 7.2 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 125 SX?
The 2020 KTM 125 SX has a Capacity of 124.8 ccm (7.62 cubic inches).
What engine power does the KTM 125 SX have?
The 2020 KTM 125 SX has a Power of 15.0 HP (10.9 kW).
How many gears does the KTM 125 SX have?
The 2020 KTM 125 SX has a Gearbox of 6-speed.
How much does the KTM 125 SX weigh?
The 2020 KTM 125 SX has a Dry weight of 87.8 kg (193.6 pounds).
Shop this bike
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The 2020 KTM 125 SX is an impressive motorcycle that offers top-notch performance and power. This model is perfect for riders who are looking for a lightweight and agile bike that can handle rough terrains with ease. With its powerful 125cc engine and advanced suspension system, the KTM 125 SX delivers a smooth and thrilling riding experience. Additionally, its sleek design and high-quality construction make it a standout choice for anyone in the market for a reliable and versatile off-road motorcycle.
In conclusion, the 2020 KTM 125 SX is an outstanding option for riders who demand nothing but the best. Its superior performance, lightweight design, and durable construction set it apart from the competition. Whether you're a professional racer or a weekend warrior, the KTM 125 SX is sure to impress with its speed, agility, and overall performance. If you're in the market for a high-quality off-road motorcycle, the 2020 KTM 125 SX is definitely worth consideration.
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