On 10/6/2016 10:23 PM, wrote:

Question: Has anyone ever created a dual side drive bike? Chainrings and cogs and derailleurs on both sides. Have to somehow make the shifter shift derailleurs on both sides in sync.

Yes, like almost every other bicycling "innovation," that's been done
before. Back in the 1890s, when gearing technology was very much in
flux, there were quite a few systems that used multiple chains. Some
had multiple chains on one side of the bike, some on both sides.

Some of these are mentioned, diagrammed and photographed in _The Dancing
Chain_ by Frank Berto. I'm now looking at a photo of such a system on
page 65 of that book.

--
- Frank Krygowski