Since my commutes are based on my schedule, and not on the weather, I bought a 1300 w geared hub motor and an 840 wh battery. A 25 mph headwind pre-electricity in 9/18 ran my 3.7 hour trip to 6 hours at 4.3 mph. With that much power, I can make it into 25 mph headwind at 8 mph as normal.
30-35...