Motor noise at 18mph

[liamc]

Hi all, I was wondering if someone could help .
Everytime I hit 18mph or higher using pedal assist or throttle my rear hub motor Makes a strange loud noise and bike stops assisting .

When wheel is off the ground there is no sound apart from the motor running normally .
Iv checked brake discs etc for non motor issues .
Why is it only at a certain speed it happens? If I was to pedal without motor at that speed, no sound .

 

[lannabi]

I have similar issues on beaufort Bonnie ebike
I have a video about the noise for anybody that can help please

 

[lannabi]

Motor noise

 

[Chargeride]

Sounds like the controller to me.

 

[lannabi]

Sounds like the controller to me.

Can it be the controller, even if the bike motor run smoothly on plate road

 

[Chargeride]

I can only relate to my issue with a hub drive, it was fine at low speed and gentle climbs, but once serious current was being pulled the motor started to sound like it was self destructing, I was convinced the gears had been stripped.

Took it apart, perfect, put on a new controller..solved.