GN125 / BD125 4-Speed Gearbox Assembly
Brand new replacement 4-speed gearbox assembly suitable for selected GN125 / BD125-style 125cc manual clutch engines, commonly used in pit bikes and similar applications.
The gearbox is supplied as a complete two-shaft gear assembly, including the input and output shafts with gears installed.
Ideal for replacing a worn, damaged or faulty gearbox.
Key Features
- Brand new replacement gearbox
- Suitable for selected GN125 and BD125 manual clutch engines
- 4-speed gearbox
- Complete input and output shaft assemblies
- Supplied with gears fitted
- Suitable for many 125cc pit bike engine applications
- UK stock
- Fast UK dispatch
Specifications
Output Shaft
- Overall shaft length: 119.5mm
- Output section diameter: 17mm
- Bearing end diameter: 12mm
-
Gear tooth counts:
- 23 teeth
- 20 teeth
- 16 teeth
- 11 teeth
Input Shaft
- Overall shaft length: 116.5mm
- Spline diameter: 17mm
- Bearing section diameter: 12mm
-
Gear tooth counts:
- 36 teeth
- 31 teeth
- 27 teeth
- 24 teeth
Package Includes
1 x Complete 4-Speed Gearbox Assembly
Includes both input and output gear shafts as pictured.
Compatibility
Designed for selected GN125 / BD125-style 125cc manual clutch engines.
There are several variations of Chinese pit bike engines and gearboxes, so please compare the shaft dimensions, spline sizes and gear tooth counts with your original gearbox before ordering.
Do not rely on engine capacity alone when checking compatibility.
If you are unsure whether this part will fit your engine, please contact us before ordering.
UK Stock & Delivery
Stocked and dispatched from the UK.
Fast UK delivery available.