Folding ebikes that are light weight, and that I currently own, are the Lectric XP Lite (single speed w/rear hub motor and gates carbon blet drive) and the Dahon Unio E20 (mid-drive, great ride quality, torque sensor). Dahon also has the K-One (rear hub motor w/gearing) and the K-Feather (smaller 16" wheels, single speed). I also have the Fiido L3, but that's more of an seated electric scooter, since pedaling it is useless. It's fun to cruise around on and take in the scenery or use for commuting (since it's small and gets about 50 miles per charge - they're claiming 124 miles per charge). It's around 50lbs though, so it's a little heavy, but doable.