Rear hub motor, worth fixing? 48v 1200w 700c

bbells

10 mW
Joined
May 14, 2016
Messages
20
I parked my ebike the other night after riding. Everything was fine. The next morning the rear hub motor would not do anything. By the process of elimination I determined my rear hub motor is the problem - I connected the hub motor from another bike to my setup and the hub motor on the other bike worked fine. I spun my rear wheel will put out a couple volts when spinning - From any 2 of the 3 wires. There is no increased drag when spinning with the bike powered on versus when it isn't. IMHO, that does not point to a bad hall sensor. But, I could be wrong.
Question: Is it worth tearing open the hub and trying to fix this problem? Or should I just buy another wheel and hub motor? If I tear it apart, any idea on what I should be looking for? Thanks!
 
Sounds like a poor connection between motor and controller, probably on the motor side, possibly at the wire exit from the axle (especially if it's been banged up at all there).

Most likely it's in the hall wires, if you're able to read voltage across the phase wires. (halls have nothing to do with drag on the motor)

Ebikes.ca has a Learn tab with Troubleshooting info on how to test the halls (there are also a lot of posts adn threads about it here, too).
 
Thanks! I was also thinking it might just be the wires as they leave the axle. I will be taking it apart in a few minutes and will post my findings. Hey, I have nothing to lose at this point. Thanks!
 
Thank you Amberwolf! Several wires right on the outside of the axle were broken. I took the wheel off, unscrewed the 8 screws around the hub on the wire side, tapped the axle on the other side (with a nut on it of course), cut all the wires coming into the hub and about 4 inches on the outside of the hub, pulled the bundle of wires out from the hub side of the axle, pushed the fresh wire in, soldered and heat tapped the connections, put it back together and it worked. The hardest part of the project was taking the wheel on and off the bike. In a 1-5 scale I would rate it as 2 for both hardness and technical expertise needed. Relatively easy job.
 
Glad it worked out. :)

This might prevent it from happening next time

http://www.ebikes.ca/shop/electric-bicycle-parts/motor-hardware/u-bracket.html
 
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