Hub motor suddenly feels like a rubbing tyre..

paulstung

100 W
Joined
Jul 18, 2016
Messages
124
Afternoon all. I was just ridden home from work and out of nowhere I felt a rubbing just like an off centre wheel , and causing a terrible vibration through the whole bike, but after checking it was fine, so any ideas guys??
 
When you said it was fine, what did you check?

It could be a bad baring, a loose magnet, a loose axle, a misaligned brake rotor, it could be a lot of things.

Can you give us more detail of what you checked?

:D :bolt:
 
Hi there mate, I've checked rotor / brake caliper, wheel alignment, freehub, and axle, the bearings and phase wires, are next on my list.

Is there any way of checking for a bad bearing without removing the wheel and or motor side covers, ie wheel wobble or something similar?


Update, axle and bearings checked and both are fine, and also the phase wires.

I'm stuck for an answer..
 
If your motor has hall sensors, check the connector to make sure it is fully seated.
 
It's running sensorless thanks to an ever helpful motorist deciding whether to pull out of a junction or not.and thinking yes I will pull out right as I'm in front of her car, sorry I should have made that clear.

Opened and checked everything put it all back together and if was working perfectly. Right until I was about 3 miles away from home, the jerking started and then it stopped. It won't even move when self learning. Well it dies but a jerk forward and then a jerk back. I'm completely list to what it could be..

It can't be controller related because it's doing the same without one connected, so I'm leaning towards maybe winding/ phase wire issue, because to me it feels like there's resistance in the wheel spinning almost like when you hold 2 phase wires together and it doesn't spin..?? But any help is greatly appreciated.
Thank you everyone for the help so far.
 
Most likely the phase wires are shorted together at the axle exit from wire damage due to the original problem taht took out your sensor cable.

You may not be able to see this damage, because it could be as simple as a nick in the wires from the actual axle hole edge...but moving the cable may temporarily remove or create the short.

you can find out whihc phses it is by manuyally shorting each pair of phses. the ones that don't make the probelm worse are the ones that are shorted.


it could also be windings shorted to the stator laminations, which can be intermittent but often recurs under vibration/bumps.
 
That's pretty much what I decided that it probably was. Unfortunately I can't get either of the cover plates of to add new wires, they only slide of about 3 inches, it's an old motor with almost 25,000 miles so I think that I will put her to rest. Over the last 3 weeks there has been problem after problem.

Luckily I had a 3000w halo motor not being used due to the dropouts on my bike being about 1/8 inch to narrow, but I took it over to a friend and he machined the axle down a touch and extended the threads. So I can at least get to work tomorrow morning, I've got a new kit ordered for Thursday delivery,

Thank you everyone for the help
 
It is not that hard to refurbish a motor as long as the windings havent burnt and the magnets havent cracked or delaminated.
Soldering wire to the phase windings takes a big high wattage soldering iron.
Routing wires through the axle takes a bit of work.
Other then the last 2, its all very simple.
Bearing replacements are easy.

Make sure the wires inside the motor are not touching the cover plates because they will get damage when the motor spins. The stator with its axle is stationary while the magnet ring spins.

https://www.electricbike.com/motor-tech-learn-the-terms-part-1/
 
Have you checked the mosfets in your controller?

:D :bolt:
 
Have you checked the mosfets in your controller?
:kff:

Be lucky if ya find clear visual evidence, but a quick check of the mosfets with a multimeter would suffice. Just hope nothing down or up stream isnt pooched.

https://ebikes.ca/learn/troubleshooting.html
 
Oh yes this motor has been refurbished a couple of times, tbh I'm a little bit sick of bringing her back to life. In all honesty Im thinking that it's time to put her to rest..

As far as the controller I tested what could be and it's fine and working on the adapted spare motor.


After getting the spare motor all connected and fitted onto the bike the problem is still there, the motor spins when it is upside down but as soon as I get it on the wheels it just doesn't want to run it jerks forward a cm or two then jerks back to where it started. I'm thinking that it's probably the controller and not the actual motor?

Any ideas guys? It doesn't really matter to be honest because I've got a new kit being delivered by Saturday and a 80A sabvoton controller coming by the 5 of March, so I'll plod on with the included controller and rely on using the sw900 that I have here to limit the current because I have a 60v battery
 
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