“Yup two chains on teh bottom one, presumably just two sets of rings and a flip-flop hub”
Aren’t flip flop hubs fixed on one side though? Off-road fixed could be somewhat difficult
Also, if you put a driveside crank on the driveside, you’ll need a driveside pedal too (would need to rebuild a non-driveside pedal with a driveside axle for an SPD to work, or a forward weight bias type flat pedal (like a proper MTB one). Once you’d done that, the pedal would unscrew with pedalling anyway?
Unless its a crank arm intended for a tandem, with the pedal threads the correct way round to use on the non-driveside
“does the A bob like hell when pedalling? “
Should that be:
does the A bob like hell when pedalling singlespeed?