The idea above would only work properly with two freewheels, one of them clicking in the opposite direction to the other. I'd assume also that this would require a customised hub. There would also presumably be an issue with getting even chain tension.
Sheldon Brown did something similar involving a Stermy Archer hub and a couple of fixed sprockets giving him three fixed gears. Seem to remember a note at the top of the article saying "if you have to ask questions about any of this, don't attempt it".
The idea above would only work properly with two freewheels, one of them clicking in the opposite direction to the other. I'd assume also that this would require a customised hub. There would also presumably be an issue with getting even chain tension.
Sheldon Brown did something similar involving a Stermy Archer hub and a couple of fixed sprockets giving him three fixed gears. Seem to remember a note at the top of the article saying "if you have to ask questions about any of this, don't attempt it".