The EVELO Automatic Transmission senses bicycle speed, as well as your rate of pedaling (cadence) to make gear adjustments for you as you ride. This system also offers Manual shifting as well, so you can switch between Manual and Automatic on the fly as you ride!
Take a look at the link below for a video on how this shifter system operates: https://www.evelo.com/blog/continuously-variable-transmission-cvt-on-evelo-electric-bikes/