Originally Posted by
RubeRad
I can't find it right now, but I remember reading once (I think Sheldon Brown?) about a 2x2 "fixed" drivetrain carefully designed to have the same wrap,
Rivendell used to have a bike like this - the Quickbeam - it had track ends, a flip-flop hub, and a two-ring crank. I don't think it ever got very popular but I saw Grant himself riding it once on Mount Diablo - he got to the top of the climb and got off and changed to the downhill gears by flipping the wheel and manual redistribution of the chain.
Anyway - as for a tool, I recommend a piece of wire clothes hanger bent into an appropriate shape.