With regard to range and motor power:
Bear in mind that, the peak efficiency of a motor is achieved when the output losses are equal to the parasitic losses. A larger motor will have greater parasitic losses and it's peak efficiency state will be at a greater output torque.
Given a maximum speed of 16 mph, you can increase your average speed by going up hills faster with a more powerful motor, without using significantly more energy.
You could have a single speed system (e.g. hub motor) with a motor capable of sustaining you at 16 mph up any gradients you are likely to encounter. Assuming an 80kg rider on a 25kg bike and a maximum gradient of 16%, you'd need a maximum power of around 1300 Watts. To sustain that 16mph on the flat you would only need around 120Watts. So, over 10:1 range of power requirements, for this case........
Miles
Bear in mind that, the peak efficiency of a motor is achieved when the output losses are equal to the parasitic losses. A larger motor will have greater parasitic losses and it's peak efficiency state will be at a greater output torque.
Given a maximum speed of 16 mph, you can increase your average speed by going up hills faster with a more powerful motor, without using significantly more energy.
You could have a single speed system (e.g. hub motor) with a motor capable of sustaining you at 16 mph up any gradients you are likely to encounter. Assuming an 80kg rider on a 25kg bike and a maximum gradient of 16%, you'd need a maximum power of around 1300 Watts. To sustain that 16mph on the flat you would only need around 120Watts. So, over 10:1 range of power requirements, for this case........
Miles
