Originally Posted by
peugeot mongrel
If you are going to set it up single on the outer ring position you want the ring 3mm closer than it's position as a double, more like 109. If you get the spindle too short on some frames using a double spider the inner offset will hit. Like Bill said you can always use a spacer to help.
Before you go too far, measure all the clearances to teh frame: crankarm to chainstay, chainring closest point to chainstay, chainring bolts to chainstay, anything else that could represent a limiting condition or a source of metal-metal interference. Recognize that you can't move that crank closer than those gaps you measure. Just know the limitations.
But I agree with Danno: put it together, see how it works, measure the clearances and see what the next one to try should be.