New Style Motor Help

[Christenson58]

Hello All, I have a friend that asked me to help him with his Rad Rover. Does anyone have any leads on where I can get info on this motor? It's off a 2-3 year old Rad City 5 Plus. It's got a bad Hall Sensor and this motor is not like the older motors. Wiring on this one comes out the brake Side instead of Drive side, so doesn't come apart like the older ones. Trying to take it further apart at this point and it sounds like the large metal plate is hitting ring gear, but I think it will actually clear it. It won't tap/hammer out like the older motors and I'm thinking I may need to use a 3-prong puller to push it through, as the magnetic hub maybe pressed in under ring gear... but I don't know for sure.

The motor runs good when I reset the battery and punch throttle with wheel off the ground, but will flash a code 24 and stop working after first stop.
So, I want to get it apart without damaging anything to try and replace hall sensor, but for not knowing the setup behind this plate and using a puller now on the Drive side, would be me driving blind at this point. Problem is I can't find anything on it on the Web. Sorry for the crappy pictures, I should have taken better ones, but I thought I was going to just be replacing the motor, so I put it back together and back on the bike to make it still ride-able. TIA

[Christenson58]

Just finished editing the video where I diagnosed the condition: https://youtu.be/09R8ForKmsM?si=z6vYmmPnWXeC1FQ_

[JimInPT]

Sorry, I'm no good to you with your specific problem, but I wanted you to know how much I appreciate seeing others willing to tear down greasy mechanical things on the kitchen countertop.  I usually draw the line at the bedspread, though.

[Radding Along]

You first mentioned that it was a Rover and then said it was a City 5. Which model is it?

Parts for those motors are semi propriety. It may be hard, if not impossible to find the parts. And if you do, the quality may not be great.

Those bikes are selling for around $2,000. Why not just purchase a new rear wheel for around $500? It would be well worth it!

[Christenson58]

"Sorry, I'm no good to you with your specific problem, but I wanted you to know how much I appreciate seeing others willing to tear down greasy mechanical things on the kitchen countertop.  I usually draw the line at the bedspread, though."


Yes! It's great to be single! =)

[Christenson58]

"You first mentioned that it was a Rover and then said it was a City 5. Which model is it?

Parts for those motors are semi propriety. It may be hard, if not impossible to find the parts. And if you do, the quality may not be great.

Those bikes are selling for around $2,000. Why not just purchase a new rear wheel for around $500? It would be well worth it!"

I call all their bikes Rad Rovers, but it's a City 5. Yes a new motor/rim $600, but this wheel failed with under 1000 miles, so buying a new one for 1/3 of the price of the whole bike, with no guarantee that the new one will be better than the original one, doesn't instill  a lot of confidence in another $600 investment. Especially when there seems to be controller issues with these models also.

If I can get the new style motor apart without damaging it, I may be able to solder in a new Hall sensor very cheaply. Again, this design is different than earlier motors and working blind.

Also, for $600 I would prefer to throw a whole new kit at it, making it stronger and less proprietary, but it's not a true 175mm dropout and with a rigid aluminum frame, stretching it to fit a true 175mm is not an option. So, that's why I'm here seeing if I can scrounge up any helpful info. - Thanks!

[Radding Along]

I have never heard of one of those motors failing. I?m sure it has happened, but it?s a very rare occurrence.

Are you sure it?s not a controller issue? A bad controller can do exactly what you are describing.

If you can find another City 5+ bike in your area, mate it with your bike to see what happens. Put the bikes side by side and plug their motor power wire coming off their controller to your motor. If it powers your motor just fine, then you know you have a bad controller.

[Christenson58]

"
I have never heard of one of those motors failing. I?m sure it has happened, but it?s a very rare occurrence.

Are you sure it?s not a controller issue? A bad controller can do exactly what you are describing.

If you can find another City 5+ bike in your area, mate it with your bike to see what happens. Put the bikes side by side and plug their motor power wire coming off their controller to your motor. If it powers your motor just fine, then you know you have a bad controller."

I contacted Rad Service Techs and gave them a link to the video, they said to replace the motor/wheel, so now it's my friend's decision on what he wants to do. If he says he's willing to buy a new motor from them, I'll try taking the motor apart without breaking anything (like I said new design) if I get it apart in one piece I'll try soldering new Hall sensors, then throw the wheel on my truing stand next to the bike and see what happens... Thanks!

[JoeSoMD]

The Bafang M155 motor on my 5+ failed about a year ago on me - after 3800 miles - I use it each day to commute a little over 30 miles round trip to work each nice weather day.  It was a hall effect sensor.  I have not been able to find a replacement motor assembly because I believe, like others have written, that the motor is proprietary to Rad even though it is built by Bafang.  The design of this motor assembly is unlike most others, the motor side of the assembly is on the left (brake) side and opposite the chain side.  You can tell because that's the side where the motor cable comes out of the axle.  The importance of this difference is that the motor cover is on the chain side and not the motor side.  To remove the motor you have to remove the planetary ring, which is shrunk fit into the motor housing.  I'm a decent diy mechanic, and a professional lives across the street; we did not have a three jaw puller between us that would work.  So we built a custom puller but could not get the ring to budge.  We believe the only way to get it off is to heat the housing so it expands and then, in conjunction, use the custom puller.  But we worried what the heat would do to the housing and spoke butts.  So I've unlaced the spokes from the motor housing hub and next step is to apply heat to just the hub.  I'm in no rush though because I bought a replacement from Rad for $600.  Even if I can get that planetary ring out I now have to re-lace the spokes into the rim and re-true the wheel.  I would also have to chill, in dry ice, the planetary ring and try to accurately set it in the motor hub - not a trivial task. Or maybe I can just heat the hub up again to expand it. For me this has been a 4 hour job so far, and to re-lace the wheel and true it will be another 6 or so hours.  I do like tinkering, but it's better for me to go to my job and earn the money to pay Rad for a replacement wheel assembly rather than using my precious off time to replace a $3 hall effect sensor.  My big takeaways are:  never buy an e-bike with a proprietary motor and never buy an e-bike with a motor that is not removable through the hub cover - unless you are willing to accept that the motor can't be replaced.

[Christenson58]

JoeSoMD - Thanks for the reply - Exactly what I ran into - Ordered Wheel - Video I made showing the difference - https://youtu.be/43cZR2jKUOE?si=k_UBb96WrLZQV-HF