[Forge36]

Bikes typically have a weight rating. Mine has 150lbs of cargo capacity (is a cargo bike).

[analog31]

I don't know if this figures into the engineering formulas, but an e-bike needs to be stronger due to the higher speeds and power levels. On a human powered bike, if you're hauling 150 pounds, you're probably going pretty slow.

My friends who have e-bikes go through a lot more "consumable" parts such as chains, tires, brakes, cogs, and bearings.