Using a 68mm BBS02 in a 100mm bottom bracket?

[ballpoint]

I'm planning on building a bike with a Qulbix 76 frame and QS205 motor. I'm currently using a bbs02 on a mountain bike and I'd like to temporarily put it on the 76 frame while I save up for a new motor, battery, and controller, since those things are gonna cost me a couple of paychecks. My bbs02 is sized for 68mm bottom brackets, and the 76 frame comes with a 100mm bottom bracket. How would I go about fitting the motor securely in there? Is there a purpose built adapter I can buy?

 

[amberwolf]

What are the mechanical differences between a 100mm BBS02 (if they make one) and a 68mm version?

Those are what you'd have to emulate to do such a conversion.

Based on this page

California Ebike Easy Install Fat Bike Modification Kit for BBS02

California Ebike introduces our NEW press in Fat Bike Modification kits for Bafang BBS01/02. Designed and assembled in California This kits do not require the threading tools and special tooling that our original kit required. All one needs to do is disassemble the BBS01/02 as before, (see...

california-ebike.com

you'd need a whole new crankshaft and some other parts; I suspect using that kit is your best option.

California Ebike introduces our NEW press in Fat Bike Modification kits for Bafang BBS01/02. Designed and assembled in California


This kits do not require the threading tools and special tooling that our original kit required. All one needs to do is disassemble the BBS01/02 as before, (see video) and install the the new components as shown. For a more permanent install, you may want to use structural epoxy when assembling the extension tube or TIG weld the extension tube to the Bafang axle tube once it is pressed into place. We feel this kit will make converting your Bafang mid drive to fit a FAT Bike much easier and definitely more cost effective.


This extension is not compatible with BBSHD motors.

 

[tomjasz]

We sold a bunch of the kits. The BBS02 is not the right motor for a Quilbix 100MM bottom bracket. Treat it kindly. The BBSHD is a much better choice for that frame. Personally I'd save up and put a Lighteningrods kit on it! Lightning Rods

 

[2old]

The kit above has been around for a while and I haven't heard anything negative (although it would be a little under powered). Plus you could either use it on a fat bike or sell it when you procure the new parts.

 

[ballpoint]

What are the mechanical differences between a 100mm BBS02 (if they make one) and a 68mm version?

Those are what you'd have to emulate to do such a conversion.

Based on this page

California Ebike Easy Install Fat Bike Modification Kit for BBS02

California Ebike introduces our NEW press in Fat Bike Modification kits for Bafang BBS01/02. Designed and assembled in California This kits do not require the threading tools and special tooling that our original kit required. All one needs to do is disassemble the BBS01/02 as before, (see...

california-ebike.com

you'd need a whole new crankshaft and some other parts; I suspect using that kit is your best option.
View attachment 347545

This kit looks like it would work great, thanks.