If I can figure out this sprocket to ww motor attachment, what it might do is cut out the vibration from the tire thread being transferred to the motor. If that happens, it might prolong the life of the motor. I think a really nice combo would be, is the sprocket (from an old ebike I had, that drove a bicycle chain,) placed on the end of a ww. then use the hub of a coaster wheel as the drive roller. That sounds to me to be about the right ratio of drive wheel diameter to sprocket to shaft diameter. I have built the drive using the rear hub of a coaster wheel before it was with an electric motor.
So if someone can come up with a really good way to attach the sprocket to the drive shaft extension of the WW we might have a really durable setup. I noticed that several of the diy builds use the gravity clutch that shoes and i worked with. I don't remember who was doing it first, I do know we probably stole it from someone else though. I'm thinking that I will probably use that again maybe with a cable and lever lift system to get the motor off the tire for stopping and starting.
My project for today is to build a test stand and motor mount. It's been a long time since I worked on one of these things. To be honest I am considering a friction drive kit from BGF but I want to try these again first. I do not plan to replace any of my Ebike batteries or other parts. If anyone quotes me I will deny saying this but I have been disappointed with some of the things about the ebike.
I think that all and all the motors are more solid than the small motors on gas bikes i have built. Possibly not true if I were to build with a tiller motor. Some of those gasoline horizontal shaft pump type motors are pretty darn good. The electric motor is pretty bullet proof (even thought i have burned up a couple) It is all the other bits and pieces I don't care for in the ebike system. In spite of what some people think I have bought and destroyed close to a dozen controllers. I find them far to easy to damage since I rewire and reconfigure my bikes all the time. The power supplies are a joke to be honest. SLA batteries require a tag along trailer for me to get enough of them on board. The lightweight batteries are prohibitively expensive to my thinking. So I am either going to go back to gasoline or give up power bikes completely. Don't be shocked to see me on a carbon tech bike one day with all my hair shaved off.