Noisy motor with ku65 controller.

[Alan Quay]

One of my bikes (well the Mrs bike to be precise) has an 8fun 24v, 250watt sensorless motor from a hilltopper kit by Clean Republic.

I am running it from at 36v with the original controller (15amps peak). It's quite a nice little controller, but looks a little fragile, so I bought a KU65 to replace it. The KU65 works just as well, but causes the motor to make a lot of noise. At about 12mph the noise is at its worst, with an extra nipple turning resonance going on.

Needless to say, the other half is not happy with this, and will only ride it after dark with this controller.

Any ideas other than get a new wife?

 

[Deleted member 4366]

The more power, the noisier with those motors. If you can imagine the electrical pulses coming at it tapping it round. The taps are now 50% bigger. Having said that, the timing of the pulses, which varies from controller to controller, can also make a difference. It's always worse running sensorless too.

Other than a different controller, you could try reducing the current a bit by adding a few crimps to the shunt.

 

[KirstinS]

I found my 8fun 36v motor runs noisier on a ku65 at 36v than the stock controller

However the ku65 does run faster at around 17/18mph hot off the charger( when unrestricted) and has a higher amp rating so maybe that's a part of it

I then run the setup at 48v most of the time and have done close to 10,000 miles on it

It make a hell of a racket these days
!

 

[Alan Quay]

Thanks all.

It must be a timing thing, as both controllers are (at least were) running at the same volts/current. The noise is only a problem with the KU65.