You need to specify your requirements first, commute or recreation, distance traveled, elevation gain, wind, weight, etc. There are several pretty good bikes for various disciplines now, Stromer for commuting, too many to list for off road. I built a 35 pound BBS02 bike (3.5 pound 52V, 6 ah battery) that rides fine with no assist and I use Level 1 (of 5) the other half of the time. What I'd like is a mid-motor half the weight of the BBS02. GNG seems to be developing one and I can envision a 26 - 28 pound dirt bike.