Re: A new shift concept for the engineers....
Like the patent guy said, "everything has already been invented". Attached are pics of my first attempt at gearing a motorized bike. I too felt this was going to be a simple solution but it turned out not to be the case. Going with a derailleur on the left or right causes problems with a fixed rear sprocket and the want to bump start. But maybe you all can find better solutions to the problem than I was able to come up with.