Hub Motor Trouble Under Load

[omar0]

Hello.

My 1500W hub motor works fine (spins at full speed) under no load. Once I get seated, it starts stuttering, doesn’t really spin effectively, and I can hear a clicking sound.

How can I diagnose this?

 

[offGridDownUnder]

How can I diagnose this?

Step 1 (always):
Give us more information.

How long have you had it?
What is it's history?
What else is attached to it (what bicycle, what controller, etc.)?
Did it work before? How recently?
Apart from the symptoms you report, what else has changed recently - including collisions, component changes, etc.?
Did you change any settings? Were you trying to get it to behave differently?

 

[omar0]

Step 1 (always):
Give us more information.

How long have you had it?
What is it's history?
What else is attached to it (what bicycle, what controller, etc.)?
Did it work before? How recently?
Apart from the symptoms you report, what else has changed recently - including collisions, component changes, etc.?
Did you change any serttings? Were you trying to get it to behave differently?

Hello! We use it for delivery so it works for long hours. We’ve had it for a few months and it’s done a few thousand kilometers. It’s prebuilt so I’m not sure about the specifics of the controller/motor, but it’s cheap. It’s not a controller issue because we swapped the motor of another moped into it and it worked fine. It was working up until a few days ago.

No collisions, component changes, or setting changes at all

 

[amberwolf]

The most common causes of loaded problems vs unloaded normality are connection faults between motor and controller for either phases or halls or both, damaged wiring between them (usually at the axle exit), and/or overheating (or water damage) causing FET failure in the controller, and/or hall sensor failure inside the motor. Occasionally it's a battery issue where voltage under load drops so far that the controller LVC engages, voltage rises, LVC disengages, voltage drops, and that repeats until load is removed.

You'd have to test each of these to verify which one is causing it.

If the motor fails in another otherwise completely working bike (since this one's controller/battery/etc are working with a different motor), then the problem is almost certainly within the motor, it's cabling, or connector, which narrows down the troubleshooting considerably.