BBSHD BB fitment question

[rilot]

Hey all. I've been measuing up my frame ahead of a BBSHD purchase but I'm unsure about my numbers so could do with someone more knowledgeable checking them for me.

BB is a normal square taper 68mm item so we're all good there. What I'm concerned about is the version of BBSHD I need to clear the chain stays.
I've followed this guide: https://www.empoweredcycles.com/blogs/news/101474694-bottom-bracket-standards-and-bafang-mid-drive-motors and ascertained that I need about 10mm of offset from the BB shell to get the required 70mm of clearance to the rear.
Now, that guide says anything over 8mm and I need to go with the 73mm version of the BBSHD (which is nearly impossible to find in the UK). What I'm wondering is can the casing of the secondary reduction gears (which is the bit I'm assuming will foul the chain stay) be adjusted or ground down a little?

 

[tommie]

Not a problem,
i have dealt with this company on a couple of occasions,

https://www.aliexpress.com/store/product/8fun-bafang-48V1000W-electric-bike-kit-for-fat-electric-bike/705369_32484856225.html?spm=2114.12010615.0.0.9d3da095mvTi97

 

[Paul chef]

Hey all. I've been measuing up my frame ahead of a BBSHD purchase but I'm unsure about my numbers so could do with someone more knowledgeable checking them for me.

BB is a normal square taper 68mm item so we're all good there. What I'm concerned about is the version of BBSHD I need to clear the chain stays.
I've followed this guide: https://www.empoweredcycles.com/blogs/news/101474694-bottom-bracket-standards-and-bafang-mid-drive-motors and ascertained that I need about 10mm of offset from the BB shell to get the required 70mm of clearance to the rear.
Now, that guide says anything over 8mm and I need to go with the 73mm version of the BBSHD (which is nearly impossible to find in the UK). What I'm wondering is can the casing of the secondary reduction gears (which is the bit I'm assuming will foul the chain stay) be adjusted or ground down a little?

The bbshd is for 68-73mm B.B. apparently spacers are provided with this kit (there isn’t a 68 and a 73 version ) my cube has a 68mm B.B. but I’ve had to go with a 100mm Version as my chain stays are wide but I need to now get spacers to take up the extra width. Wheeliepete has been very helpful in giving me advice, not sure how to link to my thread on it

 

[rilot]

I think I'm going to go with the 100mm version and shim it. I guess it's better to have one that's too wide than one that's too narrow.

 

[Paul chef]

I’m in the process of trying to find shims wide enough ideally 2x16mm wide would centre the motor but possibly throw out the chain line meaning I would need to shim one side more than the other and/or purchase a bling ring

 

[rilot]

I've pretty much already decided I will want a bling ring so that's no issue.
I was thinking that some size 8 steel tubing (40mm ID) that is cut to the correct thickness might work for shims. Size 7 would be too small @ 32mm I think. I'm sure I can find something that's steel and 35mm ID somewhere.

Edit: Found this: https://www.ebay.co.uk/itm/MILD-STEEL-ERW-ROUND-TUBE-1-METER-LENGTHS-26-DIFFERENT-SIZES-10mm-76-1mm/152397405225?var=451679874509&hash=item237b97dc29:m:mE6cHPDlMJMj8WIyPMgy0hA

They do 38mm OD with 2mm wall thickness which would be 34mm ID.

 

[Steve UKLSRA]

I use cassette spacer rings (Shimano plastic ones are ok, but Mavic do a lovely alloy one) to space out my BBS motors if needed, just the right inner/outer diameters