Gear ratio effect on stopping/skidding

mashton I think that it is possible to have a different gear for forwards and backwards on a fixed wheel.

If you make a fixed by having two chains and two freewheels, each one fixed in a different direction, one on either side. By careful adjustment of chain length, you could get a much larger sprocket on the 'backward' freewheel than on the forward one.

Can anyone see a reason why that wouldn't work?

http://sheldonbrown.com/bichain-fixed-free.html