Help with bottom bracket for bbshd

[Nealh]

Eclipse have a few to choose from if in stock.
Woosh or Jimmy at BGA/Insat.

 

[wheeliepete]

Spacers don't come with the motor kit, Luna in USA do a spacer kit. You can use BB spacers, but I don't recommend using them as they are not a good fit and you have quite a large gap to fill. Try and find a retired engineer with a lathe, I find they are usually happy to help for not a huge cost.

 

[Paul chef]

Spacers don't come with the motor kit, Luna in USA do a spacer kit. You can use BB spacers, but I don't recommend using them as they are not a good fit and you have quite a large gap to fill. Try and find a retired engineer with a lathe, I find they are usually happy to help for not a huge cost.

Any idea of the dimensions, I'd like to get a few different ones done locally, ready for when my kit arrives

 

[wheeliepete]

1. ex. diameter of BB+1mm external and 34mm internal. Diameter of Bafang BB is 33.5mm.
2. You need to make up your BB to 100mm, so 16mm thick spacers will do the job. 16+16+68=100. This will keep the drive central, the downside is with the bafang chain wheel, it will push your chainline out and you may find lower gears difficult/impossible to use. A Bling Ring chainwheel will help with this as it has a 20mm offset and will push your chainline inward to somewhere near original. Or you can offset the drive with different thickness spacers. I would hold off making spacers until you have the drive unit when you will be able to see what works best. Who said mid drives were easy eh?

This may give you an idea of what you want to achieve. 120mm drive on 100mm BB with 10mm spacers each side.

 

[Paul chef]

Thanks for that wheeliepete, I’ll have to try and find a retired engineer to help me out, my brothers a retired toolmaker and would have been ideal but he’s living in Spain now
My other dilemma now is that a down tube battery looks like it won’t fit inside my triangle so think I’ll have to look at a rear rack