My own bike design just arrived and I’ve now set up a few electric single speeds (see assembly video). The one on the left of the picture has a 350W gearless motor and uses the 10Ah battery in the rear carrier rack; the one to the right uses the water bottle style battery and has a 200W geared mini-motor. Riding the one with the small mini-motor seemed to me to be a bit under-powered. It was ok, but I like to have a higher speed and on this bike I felt that with the mini-motor topping out at about 25km/hr it was a bit weak for my liking.
However, when I increased the motor power to 350W, which uses a larger gearless motor, I was super impressed! Though it was heavier (especially with the larger capacity battery), the power was greater and it was very well balanced to the single speed gearing of the bike, not too strong so that I don’t pedal somewhat but also not so weak that I struggle. I managed to ride 45km on a single charge with this bike before the battery dropped out, it is a very efficient bike so it allows a great range. I believe the increased range to other bikes is because with the single speed I use the motor a little less on average. If I have a fast bike with gears, then I will ride full throttle everywhere in top gear and will use the battery capacity quite quickly. With the single speed, on flat ground I tend to just give myself power bursts every now and then or sometimes ride with the throttle at about half to three quarters full. I find that I ride a little slower than usual with an average speed on flat ground at about 30km/hr but I thoroughly enjoy even this slightly decreased pace to usual. On my 45km test ride, I covered reasonably flat ground but did encounter a few decent hills; I never found I had to even get out of the saddle on these large hills and was comfortable riding at a happy power input, albeit at a decreased speed.
I believe this to be one of Australia’s top electric bikes available. For my personal use, I believe that a 200W – 350W gearless motor with the water bottle style battery would be the correct balance, considering a likely range of approximately 30km with this battery option. The larger motors have a higher top-speed and more torque up hills but do decrease the great range available with the mini-motor.