4

picture of damaged e-bike hub motor, power cable, and spokes The hub motor wires are cut from near the axle and looks like I can't repair it without completely replacing it. The motor is similar to this one on Ali Express. I failed to open the motor because the screws are so tight and rusted. I am thinking of cutting some part of the rod and join the wires. This seems an easier but not a good solution. Any advices?

Update:

I was able to get my motor working by cutting the cable from near the sensor board, pulling the cable inside the motor through the shaft and rejoining/soldering from where it was originally cut. This shortened my cable few inches and it was barely reachable to the controller. See the picture below. I wanted to know if the cable can be completely replaced with no need for these joins but it's not easy as the cable was the part of the motor coil itself.

enter image description here

12
  • 3
    At the very least, you will need to provide more detail. Hub manufacturer and model and high-quality close-up photos of all relevant parts, including both ends of the damaged cable, to start with. It would also help if you explain what research you've done already; have you contacted the manufacturer to see whether they will sell you replacement parts? Have you attempted disassembly of either the hub motor or the controller? Aug 1 '20 at 18:17
  • What kind of cable is it. Just a twin wire current connection or a multi wired cable delivering power to the motor and feed-back info to the controller?
    – Carel
    Aug 2 '20 at 18:36
  • @PeterDuniho I've updated the question. Please let me know if I can provide more details.
    – akash
    Aug 3 '20 at 5:58
  • 1
    You'll need to rejoin the 8 wires, matching the colour on both sides. This is more electrical work than bicycles.
    – Criggie
    Aug 3 '20 at 8:00
  • 2
    You need to disassemble the motor and replace the cables. Requires some electrical skills. Aug 3 '20 at 12:35
2

I had a similar problem with a motor broken during shipment (luckily the manufacturer sent me a new one). I tried to fix the broken one by replacing the cable, but it's quite hard to do, because the space inside the housing is quite small, and when I tested the motor it worked for a while until the housing, by rubbing the cable, shortened the sensor cable, and broke the sensor board in the motor. I could reasonably run it sensorless, but you need a sensorless controller if this happen. Long story short is not easy at all, I'm quite good in soldering but failed in this regard. And disassembling the motor, at least with my geared unit, is not so easy as well, so if you have nothing to lose you might try it, but be prepared for a long evening of struggling.

2
  • 1
    Hello! I first struggled with opening the motor screws manually, then bought an electric screw driver which helped. I've never done soldering before but somehow managed. Please see the image in my updated question. It's a dirty work but I'm happy it's working now. The motor has a bad design and bad cable protection. I wish it was easy to replace the entire cable really easily. I'm sure there must be such ideal motors somewhere.
    – akash
    Nov 25 '20 at 3:52
  • Well, not a masterpiece, but if it works... I see some cable without protection, I suggest to protect at least with electrical tape or hotglue, better with heatshrink tube, because the case of the motor is conductive and might short circuit everything.
    – Marras93
    Nov 25 '20 at 17:18

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.