Re: A new shift concept for the engineers....
If I wanted to eliminate the dual chain system and drive from the right side, and I may, I'd look at running through the crank hub. Many automatic car trans have shaft within shaft drives. A engine power hollow shaft running around the crank. On one end of the two you'd have to use a freewheel or oneway bearing. The only drawback is getting most of your gear reduction done on the engine drive side. A hollow tube shaft is nearly as strong as a solid one. Most of the engineering would be in the building building the shaft, and going through lots of bearing catalogs. It would present a problem of how fast you'd need to pedal to get anywhere, but I'm 68, have a Cellphone, if my motorized bicycle has a problem, and two nice MTBs if I feel like pedalling around the neighbor hood.