This is just a cautionary tale. I started to install my new BBS02 motor on my Cannondale Quick5 street bike. The bottom bracket shell is a fraction of a millimeter smaller in diameter than the motor shaft, so it just won't fit. I am not sure if I could have avoided this problem with more diligent research. Do bike manufacturers provide specs for the size of that bottom bracket hole. Does Bafang provide diameter of shaft info? In any case I guess my Cannondale is too "special" so I will search for a descent second hand mountain bike and try to mount the motor on it.
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Well, my fit was not quite that tight but the motor would not go into the bottom bracket. After I took a Dremel with a shaft and an abrasive head I whittled down all the high spots and it just would slide into the bracket with a little encouragement. Mine originally went in about halfway and just hung up so I do not think it was as tight as your fit. I originally tried a hammer but it would not go in so the Dremel did the trick.
I will try to mount it on my Kuwahara Eclipse mountain bike. It is probably vintage 10 years old, but the only other choice I have. I can't tell from the specs if this is going to fit. Which of these standards applies to the Kuwahara Eclipse? https://bikeraceinfo.com/tech/bottom-brackets.html
It looks like the BBS02 was never going to fit on my Cannondale if I am reading this correctly "Two 6806 bearings (42mm OD, 30mm ID) pressed directly in frame and stop at removable snap rings" at this link: https://wheelsmfg.com/bb30a-tech-info
The BBS02 shaft is 33mm diameter.
did a little reading, there is a lot of different types of bb sizes and standards around the world. apparently around 95% of standard bike frames use 68-73mm bottom bracket. this handy chart may help you. https://wheelsmfg.com/bb-standards
luckily for my hardtail it came with a 68mm bb sealed cartridge english threading motor fit perfect. sorry your cannondale was barely off that sucks. also looking at most ebike motors and the options in jonnys shop the minimum size is 68mm up to 100mm for larger bbs.