Reduce drive side bottom bracket to fit Bafang BBS01

[newager]

I am in the process of fitting a Bafang BBS01 to a Mondraker Foxy with a 73mm bottom bracket. I have read on forums that some peole have removed around 5mm from the drive side of the bottom bracket to help with chain alignment. Has anyone done this and does it weaken or place an extra or unequal strain on the frame. I am cautious as the frame is a 27.5" replacement for a 26" original that had a weakness in the seat tube and broke! Thanks.

 

[Fordulike]

If it were me, I wouldn't compromise that area by cutting bits off, I would fit a bespoke chainring, such as the Lekkie Bling Ring

42T and larger sizes wrap around the final drive housing to improve chainline.

Brighton ebikes is a reputable place to buy one in the UK:

https://www.brightonebikes.co.uk/store/c11/Lekkie®_Bling_Rings.html

 

[newager]

If it were me, I wouldn't compromise that area by cutting bits off, I would fit a bespoke chainring, such as the Lekkie Bling Ring

42T and larger sizes wrap around the final drive housing to improve chainline.

Brighton ebikes is a reputable place to buy one in the UK:

https://www.brightonebikes.co.uk/store/c11/Lekkie®_Bling_Rings.html

Thanks for the reply, having thought about it I would have to remove some of the welding that keeps the down tube on the bottom bracket. So you were right to suggest not compromising that area.

I have fitted a 32 tooth chainring on a Precialps sprocket to which I have added a spacer so the chain just clears the motor housing. This means I can get 9 out of ten gears of an 11 - 42 cassette so I removed the 15 sprocket and used it as a spacer. Lekkie does a 40 tooth chainring but that is still too high for mtb.

 

[Fordulike]

No problem. I think I get away with using a 42T, as I run a 48v BBS02 (tweaked slightly), so the extra torque really helps pull in any gear.