BAFANG BBS01B DON'T FIT SPECIALIZED MTB COMP HT 2012 29"

[georg0307]

Hello, I wanted to ask you for help. I bought the BAFANG BBS01B 36V 250W kit with Hailong 17.4Ah battery, to mount it on a SPECIALIZED STUMPJUMPER COMP HT 29 "from 2012. The problem is the size of the bottom bracket, the cylinder of the MTB is of length 73.5 mm and the internal diameter is 45.5 mm smooth, without thread. While the BAFANG one is 65 mm + 17 mm threaded, the diameter is 33.5 mm. Can you advise me how to solve without proceeding with a structural modification of the MTB. Sorry in advance for my terrible english.

 

[peter.c]

The motor needs adaptors to fit in a push fit bottom bracket like this various types on ebay sizes
is it a carbon frame?

 

[Pedaluma]

The motor needs adaptors to fit in a push fit bottom bracket like this various types on ebay sizes
is it a carbon frame?


View attachment 40540

The bafang does not have a secondary motor mount. So these little guys would take 100% of the torque. In my opinion kids at trade school welding shop for school credit or old farmer if you buy some eggs can place an insert in the BB and secure it all of the way through, whilst milling the ends to remove 5mm of width. I needed to mill the BB of my Specialized Chisel. Note the "water bottle" has a wire coming out of it because that is the stealthy battery. No messy wires either. This Specialized is what a 'clean build' looks like.