A while back there was a discussion about what is the strongest IGH, and there were several links to gasser bikes that used a Nexus 3-speed as a jackshaft. I recall AussieJester mentioned that he broke one of these, but he had the electric motor driving the right-side sprocket as a one-speed.That being said, he was using a lot of power that was applied suddenly (more power than I would use).
I think a Nexus-3 is a great candidate to be a 3-speed jackshaft that drives the left side. If the final chain-drive from the Nexus to the rear axle has a 2:1 ratio, then I believe the torque applied to each IGH gear-tooth will be halved.The Nexus will be spinning twice the RPMs of the rear wheel, but I believe that will be acceptable. "if I ever get around to doing this"...I plan to add some type of snubbing to the throttle to ramp up the power rather than dumping it suddenly.
Daily use for me would find the Nexus used as a 2-speed (starting out in 2nd which is direct-drive, and very strong, 3rd is a 33% overdrive). First gear would be reserved for especially steep hills. If second gear is ratio'd to provide 20-MPH, then first should be around 15-MPH and 3rd would be approximately 26-MPH...48V plus limiting amps with a cycleanalyst to match the data a temp probe provides.
Even with a mid-drive used as a single-speed, changing the gear ratios for a hilly trip is as simple and cheap as a sprocket swap.
