I ordered some Absolute Black sub-compact oval chainrings for my bike and they have chainline that is a 2.5mm further inward than normal. Absolute Black claims they work with Shimano R8000 but I have a clamp-on derailluer and can't get the derailleur to go in far enough so I get chain rub in the 3 smallest small-small gears.

They told me I need to install BB spacers. :-/ I'm not too happy because these were advertised as working with my components, but if I can buy a $5.00 spacer and it works well enough, I guess I'll do it.

So the questions are:

1. Are there thin(ish) spacers that work with a shimano BB60 BB? An pointers? I googled and found dozens of options but can't figure out what is compatible with what.

2. Is there a reason to avoid using them?

3. I'm thinking I want to use the same on both sides to keep it symmetric..

Thanks!