Killer, your right about the 100 years. but the shaft system is still very problematic, a lot harder to work on compared to a chain drive What I like about the Lloyd's was its a hollow shaft with gears on each side and a bearing housed in each end. This made it light with less drag. I'd be more interested in seeing a design that hooked up to the pedal crank on the left side, thus driving the right side shaft. Everything would have to be beefed up. I could see the roller teeth shearing off at high speed or torque applications. Its a different kind of metal on metal grinding compared to a chain sprocket. Still the application is doable if someone had the time, money and skill. I just might have to dig out the old bike next time I make a trip home. If the pedal shaft could be extended then I could slap a G4 pulley(100/80T) on the left side and put the clutch bell drum assembly in line to run a belt between the two. The problems would be free wheeling the pedals, and modifying a bike to fit the shaft/gear housing on the right side. Kind of hard to picture it without the actual drive in my lap. I'm only going by my memory and the pictures I dug up. You would have to lengthen the pedal shaft anyway for a 4-stroke. Way too much manufacturing/money for me to bite at this moment.