Some company makes a spacer especially for this purpose. Can't recall who but it solves this exact problem. There's another special single freewheel that solves the same problem to.
Like this. There are others to:
https://www.amazon.com/Cyclingdeal-C.../dp/B006WRW45O
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Last edited by drlogik; 11-19-16 at 08:44 PM.