Or you could use a flip flop hub. Use a fixed cog on the fixed side and thread a multispeed freewheel on the freewheel side. As long as you are fab'n this thing, you can stretch a frame for the 150 mm or so needed for this.
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I'm not one for fawning over bicycles, but I do believe that our bikes communicate with us, and what this bike is saying is, "You're an idiot." BikeSnobNYC