Like others have stated, it all depends on the crankset and chainring combination. If you are running Sram cranks with a threaded BB and need some extra clearance, you could go with a WolfTooth GXP ring for a BB30 crank. It has 0 offset so it will sit a little further out. Putting a drive side spacer on a GXP crankset doesn't accomplish anything in terms of spacing.