Bottom Bracket Specs for Tongsheng and Bafang Mid-Drive Motors
by Brent Robinson on Oct 06, 2023
This table shows the bottom bracket specifications for fitting Tongsheng TSDZ2 and Bafang Mid-Drive motors to a bike. It lists the type, inner diameter, width, and clearance needed for each motor to ensure a correct fit.
| Requirement | Tongsheng TSDZ2 | Bafang Mid-Drive |
|---|---|---|
| Type | JIS-BSA threaded, sealed cartridge, square tapered, English or British | JIS-BSA threaded, sealed cartridge, square tapered, English or British |
| Inner diameter | Approximately 33.5-35mm | Approximately 33.5-35mm |
| Width | 68mm, 73mm, 83mm, 92mm, 100mm, 110mm, 120mm | 68mm, 73mm, 83mm, 100mm |
| Clearance | 76mm minimum from the center of the bottom bracket to the chain stay | 12mm minimum between the motor housing and the spindle |
| Compatibility | Carbon frames with BB shell casings thicker than 12mm may not be compatible | Carbon frames with BB shell casings thicker than 12mm may not be compatible |
Notes:
- If your bike has a Press Fit bottom bracket, you will need an adapter to make it compatible with Tongsheng and Bafang mid-drive motors.
- The bottom bracket width must be the same as the motor width, or wider by up to 20mm for Tongsheng TSDZ2 motors.
- It is important to check the clearance between the motor and the chain stay before installing the motor.
Please consult your bike's manual or contact a qualified bike mechanic for assistance if you are unsure about any of the bottom bracket requirements.
