Motocross Bikes
2020Thumpstar MX 50 JR
23 fields on record
The 2020 Thumpstar MX 50 JR is an entry-level pit bike designed for young riders and beginners learning fundamental motocross skills. Its lightweight 41.5kg frame, low 603mm seat height, and responsive handling make it ideal for small-framed riders developing confidence on technical terrain. Known for reliable kick-start simplicity and adjustable suspension, it delivers affordable performance for backyard practice and junior competition.
- Capacity
- 49.0 ccm
- Engine
- Single, two-stroke
- Gearbox
- Not on record
Know it? Add it → - Dry weight
- 41.5 kg
- Seat height
- 603 mm
- Power
- 5.4 HP (4.0 kW)
How it rides
Editorial estimate from the spec sheet - not lab tested- Best for
- Built for casual backyard and light trail riding, letting young riders practice throttle control, balance, and braking on a small two-stroke cross-style machine.
- Built for
- The small-bore two-stroke engine, centrifugal clutch, and adjustable off-road suspension give it a playful, forgiving, easy-to-manage nature suited to skill-building rather than outright performance.
- Not ideal for
- This bike is not suitable for adult riders, highway use, touring, or anyone seeking real speed or long-distance comfort.
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
- Fuel system
- Carburettor
- Starting
- Kick
Transmission
- Clutch
- Centrifugal
Dimensions & weight
- Wheelbase
- 1032 mm
- Seat height
- 603 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
- Fastace Adjustable Forks
- Rear suspension
- Fastace Adjustable Shock
- Front wheel travel
- 205 mm
- Rear wheel travel
- 185 mm
Brakes & wheels
- Front brakes
- Single disc. Dual piston hydraulic disc
- Front brakes diameter
- 190 mm
- Rear brakes
- Single disc. Single Piston
Other
- Color options
- Green/Black
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 Thumpstar MX 50 JR?
The 2020 Thumpstar MX 50 JR has a Capacity of 49.0 ccm (2.99 cubic inches).
What engine power does the Thumpstar MX 50 JR have?
The 2020 Thumpstar MX 50 JR has a Power of 5.4 HP (4.0 kW).
How much does the Thumpstar MX 50 JR weigh?
The 2020 Thumpstar MX 50 JR has a Dry weight of 41.5 kg (91.5 pounds).
Shop this bike
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The 2020 Thumpstar MX 50 JR is a fantastic choice for young riders looking to get into off-road riding. This smaller-sized motorcycle is designed with beginners in mind, featuring a manageable 50cc engine and a lightweight frame. The MX 50 JR offers a smooth and easy ride, making it perfect for gaining confidence and learning the fundamentals of dirt biking. With its durable construction and reliable performance, this Thumpstar model is sure to provide endless hours of fun for young riders.
In addition to its practical design, the 2020 Thumpstar MX 50 JR has a sleek and stylish look that kids will love. The vibrant graphics and bold color options make this bike stand out on the trails. With its user-friendly features and eye-catching appearance, the MX 50 JR is an excellent choice for parents seeking a safe and enjoyable motorcycle for their kids. Overall, the 2020 Thumpstar MX 50 JR is a top-notch option for young riders who are just starting out in the world of off-road riding.
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