Imagining a design for transmission from a left side output motor (China Girls, etc) to a freewheeling sprocket on the left side of the bottom bracket. This would require a bottom bracket with basically two axles - sprockets on both sides connected and freewheeling on a central pedal crank axle. Someone would have to create this of course as it is not available anywhere. Simpler than jack-shafting to the right side though with less friction and fewer parts to keep tuned and adjusted. I wonder if it could be made with any off the shelf parts or would require some real innovation and a machine shop.
Would then have all the advantages of a jack-shaft. I'd like to see a heavier - than - bicycle sprockets and chain on the right side as well to a sturdy rear hub with internal gears. Anyone?
I've done it!
It took an EXTREME!!! amount of brainstorming.
The expense of research & development(R&D), experimentation and parts that don't fit is EXTREMELY!! expensive, in terms of $$, time, determination and mental setbacks.
The end product used ALL off-the-shelf relatively INEXPENSIVE parts. The expensive part was the relentless trial and error of parts that were never made to work together.
Minor machine work and two sprockets needed welding to the shaft.
No welding, fabrication or machining of the frame itself.
I haven’t actually harnessed my 212cc engine to it yet.
It SHOULD work.
The most likely part to fail are the skinny 30mm bottom bracket bearings.
If they DO fail, then considerable fabrication and machining ($$$)will be needed to be solve this.
Either that, or I’d have to go thru expensive R&D to fix it.