I’ve installed a bafang BBSHD 1000W electric motor to my Dahon Vybe. The motor was too powerful for the cheap rear wheel and gears installed by factory (why am I not surprised), which resulted in wear and damage in the rear wheel, cassette teeths and the chain. Therefore I replaced everything with a SRAM inner hub gearing system: i-motion 3, and used Dahons Shimano rear shifter as a chain tensioner. Everything works perfectly now with top speed of 45+ km/h.
This video is mainly made for entertainment purposes l, but I’m happy to answer some questions.