Bafang Mid-drive motors are designed to fit in a bike's bottom bracket shell. In order to see if your bike will be compatible with a Bafang mid-drive motor, you will need to find out the type and size of your bike's bottom bracket.

What is the bike's bottom bracket shell? 

A bike's bottom bracket is the frame tube where the cranks are installed:

What type of bottom brackets do our Bafang motors fit?

The Bafang mid-drive motors fit bikes with standard JIS-BSA bottom bracket (also known as standard threaded, sealed cartridge, square tapered, English or British). These bottom brackets have inner diameters of approximately ~33.5-34mm. 

⚠️ Bikes with Press Fit bottom brackets (PF30, PF92, BB30, BB86, BB92, BB95, BB121, etc.) have wider diameters and do not work with the mid-drive motors as is. You would need to find an adapter (that reduces the bottom bracket inner diameter to ~34mm, also known as a BSA threaded adapter) that works with your specific bike in order to install these motors on a bike with a Press Fit bottom bracket. Unfortunately, we do not currently offer Press Fit adapters. However, you can search for them online or at a local bike shop.

What width size bottom brackets do our Bafang motors work with? 

Our BBS02 750W mid-drive motors fit bikes with 68-73mm wide bottom brackets

Our BBSHD 1000W mid-drive motors come in two sizes and fit bikes with: (1) 68-73mm bottom brackets and (2) 74-100mm wide bottom brackets

How do I measure the width of my bike's bottom bracket? 

Measure your bike frame's bottom bracket shell only and not any of your crank hardware as shown in the photo below:

How do I find out what size and type my bottom bracket is?

You can search online for details about your bike's bottom bracket. Many manufacturers list the size and type of bottom bracket that come with specific bikes on their website listings. You can also contact the bike manufacturer directly.

❗️We always recommend measuring your bike's bottom bracket to confirm the size on your end.

RECAP 👍: 

We currently offer the BBS02 750W motors in one bottom bracket size for 68-73mm wide bottom brackets with an inside diameter of ~33.6-34mm

We currently offer the BBSHD 1000W motors in two bottom bracket sizes:

  1. 68-73mm wide bottom brackets with an inside diameter of ~33.6-34mm
  2. 74-100mm wide bottom brackets with an inside diameter of ~33.6-34mm

Our motors fit bikes with standard JIS-BSA bottom bracket (also known as standard threaded, sealed cartridge, square tapered, English or British).

If your bike has a Press Fit bottom bracket, then you will need an adapter to reduce the size of the bottom bracket inner diameter to ~34mm to make it compatible with these motors. 

After searching online and measuring your bike's bottom bracket, if you are still unsure of whether our motor kits will fit with your bike, please email us the year, make and model of your bike at [email protected] for us to take a look. Please note, we only have access to the information that we can find online, we don't have the benefit of having your specific bike right in front of us! 🚵🏽

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