Here is my Chopper Mk3 that I converted some 10 years ago. I used one of the pricey “E-Bike Kits” as there were not a lot of alternatives at that time. I think it was this kit:
https://www.ebikekit.com/products/e-bikekit-heavy-duty-front-lithium-48v
It still works beautifully and even when I...