Not at all. If you just want left side drive and have eggbeaters (fixie with track hub, of course), you just whip out the crank puller and change the cranks. It will work.

Here, the trouble is that he wants a chainring on the left and right side, so either a tandem crankset or two right side pedals are needed.



The idea is great, but it wouldn't work with different gear ratios on the two sides. I you put a bigger tooth count freewheel on the left side, it will try to force the left crank turn faster than the right, as it moves more chain per wheel rotation than the smaller, right side freewheel. The very same bike could be ridden backwards without a problem, though. Then the right side would be freewheeling, spinning faster than the left, driving sprocket.

(Am I right about this??? It's really confusing)

Edit: same as the previous poster said.

Edit2: Don't build a bike with a higher ratio on the left side, either. It would go forward without a problem, clicking but something disastrous would happen if you tried to backpedal... Though I have no idea what. Chain breaks? Or am I wrong about it all?

The bike on FGG must have been one with the same ratio on both sides... which begs sombody (Sheldon, do you hear me?) to build a bike with two freewheels that has different sized cogs and rings. For example 16/48 and 18/54. It would look completely alien.