When I converted my Cannondale road bike into an e-bike I didn’t fully appreciate the value of a light e-bike. While I understand why you would want a lighter traditional bike, I didn’t think that it applied to electric bikes. Right? The motor and battery do all the work so weight really doesn’t matter, does it?
Not really. It’s a catch 22. With an electric motor, as power increases e.g. 750 watt motor, there is a corresponding increase in the weight and power needs of the motor. Further compounding the problem, as the power needs increase the size and weight of the battery increases which also increases the power needs.
So it is more of a balancing act to find the optimal power for your needs. In my case, I find that my Class 1 e-bike with Bosch Active Line 350 watt electric bike with its 500 watt hour battery gives me all the power I need and more range than my Class 3 Bafang 750 watt motor with a 840 watt hour battery. Perhaps the biggest factor contributing to better range with a smaller motor and battery is my speed. Since speed becomes the biggest factor in range and the class 1 bicycle stops assistance at 20mph a lot of power is saved. See “What E-bike Class is Right For You? Part 3: Range” for a more detailed explanation of the relationship between speed and range.
So when it comes to e-bikes bigger is not necessarily better! Another consideration with heavier e-bikes is your bike carrier/racks. Many bike carriers/racks are not designed to handle the additional weight of your e-bike. Remember, you have a lot on money riding on that bike carrier.