Strong judder under load in front wheel (brushless motor)

[Donakdyk]

Hello. I am new to the forum and have problem with my new e-bike. I hope someone can help me... When the motor (250 w AicoTech motor) is under load it makes a very strong noise and the front wheel vibrates like in this video. I tried the bike with a new motor but I have exactly the same problem. All the connections seem to be ok. Any idea?

 

[Deleted member 4366]

You have a connection fault on the motor wires. Follow the wires from where they exit the motor. There may be a connector about a foot from the motor. Check that there's no water in it, and then make sure that it's pushed fully home (right to the guide line). Then continue following the wires to the controller, where there will be more connectors. If you have bullet/barrel connectors, squeeze down the barrels and reconnect. Don't use more than half throttle when it's running like that otherwise you'll be looking for a new controller.

Some more details about your bike would help.

 

[Donakdyk]

Hello, thanks so much for your quick answer! This is a cruiser bike with an Aico 36volt 250 watt front hub motor and controller (http://www.aico.com.tw/index/product/motor_controller.html) . All the connexions look ok. Could this be a loose connexion IN the controller?

 

[Deleted member 4366]

It's a bad connection somewhere. We had one recently with the wire broken where it comes out of the motor. The wires can often get cut or damaged there. Controllers don't normally give problems, but anything is possible.

Is this a new installation or did it run OK before the problem?

 

[Donakdyk]

This is a new installation.

 

[Deleted member 4366]

I might be a false positive in your phase sequence then. Does the motor have hall sensors? If so follow this plan:
http://www.lsdzs.net/Technical_detail/newsId=33.html