Originally Posted by Shilun
I notice that there are a whole range of spacer widths available for the Granny ring ranging from 2.2mm up to 8.3mm How does one know which width to choose? Is there a formula, or do you just have to eyeball it?
The spacer thickness will vary from maker to maker and model to model. As I mentioned current Shimano road triples don't require any spacers. My new Campy Chorus triple crank also has no spacers and the granny ring bolts flat to the mounting bosses. An old SR crank I have uses 3.8 mm spacers so there is no general rule.
Do the mounting bosses on your FSA crank stick out beyond the middle chainring line a fair bit? If so it may also need no extra spacers.
If you are trying to get good indexing, the spacing has to be right so either the manufacturer makes the mounting bosses the right length or you will have to experiment with washer stacks.
Yes, about ten days ago, but no reply so far.
That's unfortunate. Where are you located and is there a local distributor for FSA that might be more responsive?