Originally Posted by
DrkAngel
From 10mph, assist will double speed to 20mph (10mph).
From 20mph, the same amount of pedal assist will increase speed 5mph.
From 30mph, the same amount of pedal assist will increase speed 2.5mph.
From 40mph, the same amount of pedal assist will increase speed <2mph.
However at 50mph, the same amount of pedal assist will increase speed ... barely ... 1mph!
The problem is that human power and motor power are NOT necessarily linearly additive. With direct-drive motors, as you try to add speed with human power, you have to overcome both the normal additional drag on the bike AND the additional magnetic drag in the motor due to eddy currents and back EMF. Your speed increase numbers from 255W human input are wildly optimistic.