The chainring adapter (sometimes called spider) offers the following advantages:
- conventional, commercially available standard chainrings can be mounted on
- it is also possible to mount 2 chainrings - on the left and right of the adapter
Thus, not only the chainring sizes available for the bafang motor, but also other chainrings can be used on the Bafang BBS mid drive motors. But you should note the following:
On the one hand, the bold circle (104 or 130 mm) and on the other hand, the number of receptacles (arms) of the spider must be observed. For example: With the following adapter "5-arm 130 BCD" only chainrings with 130 mm bold circle and 5 arms can be mounted:
The bold circle refers to the diameter of the chainring arms. In the video below we have illustrated this clearly. The smaller the bolt circle, the smaller chainrings can be used.
As with any chainring, the chain line should also be considered. The adapter for Bafang BBS01 or BBS02 motors has no offset - but the adapter for BBSHD motor has an offset of 7-8 mm inward. To determine the chain line, we have created the appropriate templates for each motor:
In addition, a pulley can also be mounted on these adapters. Thus the Bafang BBS01/02 and BBSHD mid-drive motors can be used also with belt drive.
Here you can find the video about this topic: