Changing a hub motor on an e-bike: tricky connection

Question

My e-bike hub motor appears to need a replacement (generates almost no torque when powered and, most importantly, when the wheel is rotated backward, it resists and the motor makes a very loud clicking noise). It also seems that I will have to lace the motor to the rim, but that is not the main issue.

The main problem with this is that I do not understand the connection between the motor and the controller. On my wife's e-bike, the hub motor has a 20 cm cable with a 9-pin connector on its end (HiGo Z910, I believe), which makes the reconnection rather clear. My motor, on the contrast, has a 90 cm cable going inside the frame (the controller and the battery are inside) and ending in some sort of a Molex connector (6 slots, 5 pins), see the photo below.

What motor should I consider for replacement in view of this and what are my options regarding the connection? My thoughts so far:

1. Take a motor with a short cable and a 9-pin connector, then cut the existing cable open and attach the other side of a 9-pin connector (but how?);
2. Find a motor with a long cable and any connector and change the accepting connector on the controller accordingly;
3. Try to fix the existing motor (there are no workshops capable of doing this where I live, and I have no idea how to do this).

What else should I pay attention to when looking for a replacement (apart from the connector, the voltage/power/RPM)?

Answer 1

At this moment in history, for individuals who aren't specialists and don't want to deep dive the topic just for the sake of doing one repair, the answer is get another of the same motor you have. For most of them, all the information you need to do so is on the shell.

Pairing new motor hubs with existing motor controllers to repair bikes is an area of knowledge that hopefully someone on the internet will give us all a comprehensive guide to someday, but I haven't seen it in and there are some ins and outs. It involves figuring out which cables are phase wires, sensor wires of different types, and what plays nice with what or can.

The symptoms you describe make it sound like the likeliest thing is your nylon reduction gears are worn and need to be replaced. Since the motor sounds like it's mostly useless now, one way you could approach this is open the hub, confirm the gears you have are worn and breaking up as they do, and then when you go shopping you'll have a better visual indicator you're getting the right thing.