So that was the problem was it hard to plug it back it ?
Levo Gen 2 S-Mag motor ERRORS after belt repair
- Thread starter syncro
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Is that fixable ? I think I have the same issue?
Same here. What a f.... design. I tried not to open the mainboard side, but it did during opening of the belt side door...
Now I can remove and open the whole thing again...
Had to solder the female connectors back in place on the ring sensor. Luckily it works again.
Now I can remove and open the whole thing again...
Had to solder the female connectors back in place on the ring sensor. Luckily it works again.
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sendsay
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- Mar 9, 2026
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Good evening! During assembly, one contact broke off the rotation sensor (these contacts are shown in all the photos above). I disassembled the sensor, unsoldered the wire, pulled out the board with the contact, added tin, and soldered the contact back on. I reassembled everything and checked it with a tester. Everything rings, but the error persists after assembly. My question is, could something on the board itself be damaged, such as a broken track or solder joint? Thank you.
The Brose PCB is quite robust and will generally take a lot of abuse. The torque sensor and sensor pick-up ring can fail though. Do you have Walk assistance and no ride assistance, or do you have no assistance at all on either system?
The speedo and odo work through the wheel sensor and nothing to do with the cadence and torque sensor that you have repaired. When you say you have no help, do you mean you have no walk assistance and no motor assistance at all?
If the
If the torque sensor fails, you will get no walk assist and no power assist.
If the PCB is damaged and your repair has not worked, you will also get no walk and no power assist.
It is not possible to fit a new PCB because the one you have is calibrated to the angle magnet on the three phase motor.
If the plastic pick-up coil for the torque sensor fails you will get walk assist but no power assist.
If the torque sensor fails, you will get no walk assist and no power assist.
If the PCB is damaged and your repair has not worked, you will also get no walk and no power assist.
It is not possible to fit a new PCB because the one you have is calibrated to the angle magnet on the three phase motor.
sendsay
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- Mar 9, 2026
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(It is not possible to fit a new PCB because the one you have is calibrated to the angle magnet on the three-phase motor.) This is very bad news, but tomorrow I will try to take it apart and check everything again, but I still have a couple of questions. How do I unfasten the connectors under the cover? And how much resistance should the coil have when it is working? If you know the answer, thank you.
Unfo
unfortunately you will have to be a little more accurate or descriptive with your descriptions. If you mean the wiring plugs under the printed circuit board (PCB) cover? They just clip in to the PCB. I'm not sure what you mean by "coil"? If you mean the electric motors armature (the magnets in the centre of the stator coils) then these will have resistance when the belt cover is removed, because the supporting bearing needs the belt cover in place to be able to do its job, without the belt cover the armature magnets will drag against the stator making it feel rough and difficult to turn.
sendsay
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- Mar 9, 2026
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Thank you for your answers! I've already taken everything apart and checked all the connectors and wires, everything is fine, I soldered two sensor contacts (rotation?) that the antenna connects to, just in case. Within an hour, if the guests don't get in the way, I'll take apart the engine to check the antenna. But please answer me this: what should the resistance be for a normal antenna? I need to know this in order to decide whether it is working properly. Thank you.
I think you will need to
I think you will need to post a photo of what you need. The language translation sounds like you are working on a radio! Take a close-up photo of the part and I will get you the information.
sendsay
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- Mar 9, 2026
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Good evening. I am referring to this component; to me, it is an antenna because the magnetic field rotates, and this antenna picks it up and transmits it to the board. Maybe I'm wrong, but these are the peculiarities of education))) Sorry for misleading you. It's very interesting what language you speak, can I translate directly into your language? I think it's Italian))))
How much Ohms do you have? Either you have a resistance or not, I doubt it would have kind of a short cut.
In my case the torque sensor itself was broken - not the antenna
sendsay
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- Mar 9, 2026
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How can i test it?
I don't know. In my case sometimes the motor doesn't engage when pedaling and sometimes the motor doesn't stop when I stopped pedaling.
Then i installed a new one and it was ok.
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That's happened to me before. Tnx!
This part is the torque sensor pick-up ring. It works by converting a resistance change to a voltage signal. More pedal force = more motor current. The only practical test you can do would be a continuity test, but this will not tell you anything more than the fact that you have a circuit.
If this part fails, you will still get walk assistance when you press the walk assist button on the handlebar remote switch.
If the torque sensor fails, you will loose power and walk assist. Plugging the motor into diagnostics will normally show a torque sensor fault.
By the way, I am English, so no need to write in Italian!
sendsay
New Member
- Mar 9, 2026
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I ordered a torque sensor, I'm sure you're right, your experience proves it!
Is is common that torque sensor fails? I had troubles with uneven assistant. I read somewhere that could be caused by failing cluing of that bearing which is in picture I have changed couple bearings and added extra seals. I haven´t tested bike yet after motor reassembly. This is second time motor fails like this. First motor went to warranty around 5000km.
Torque sensor itself is not a common fault but, eventually all things fail, especially when used outside manufacturer specification (eg. pedal stries, water ingress). In many cases, motor faults after belt replacement are because of improper installation. Normally, you don't have to remove the control board when you only replace the belt.
Information transfer is made by using a transformer (magnetic coupling). This transformer is also used for power transfer from mainboard to internal torque sensor electronics. One stationary coil is the part with 2 pin connector monted on the motor housing and connected to the motor control board, and the rotary coil is on the torque sensor itself (masked with white tape). The torque sensor has an internal PCB (under the blue silicone) and 4 sensing elements oriented 90degrees, glued to the shaft. If one sensing element fail, the motor could work without errors but it will give uneven assistance or other manifestation (wrong sensitivity, excessive overrun, etc.). The PCB itself could also fail but it's not a common thing. Stationary coil would not fail by itself as it's just a copper wire (insulated) wounded around the plastic ring.
No, if the bearing moves, the belt pulley will rub on the inside of the belt cover and makes a metallic scrapping noise. Even if the bearing moves only slightly and the pulley does not rub the belt cover, eventually this will cause the drive belt to fail, but none of this has anything to do with the torque sensor.
Many things can cause run-on but the most common is when the crankshaft becomes stiff to turn, usually when the needle roller bearing that supports it starts to fail.
The stationary coil can and does fail. This is a part we definitely have to replace from time to time. Next time you have a bike with walk assist but no power assist, try changing this part first.
True, but if it fails, it's from external causes, most likely improper installation on prior repair attempts.
No, they can just fail. Out of the thousands of motors we see each year, I can assure you that this part can fail without prior intervention and no noticeable installation issues from the factory. We have never really bothered finding out why, but now I'm curious, I will see if I can find a cause for you.
sendsay
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- Mar 9, 2026
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Good evening. I've assembled the motor, and everything works fine as long as I'm not pedaling while sitting on the bike. When the motor kicks in, I hear a crackling sound. I installed the clutches following a video by a Russian creator, and it seems like I did everything right. I think maybe the grease is too thick. I used PG75 grease on the smaller clutch, and on the larger one, I don’t remember exactly, but it was thicker. Please let me know how to fix this. Thanks.
Translated with DeepL.com (free version)
Translated with DeepL.com (free version)
sendsay
New Member
- Mar 9, 2026
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What an idiot!!! The belt isn't tight!!!!!
Yeah, I think you are right. I took motor apart, changed needle bearing and added extra seals. I have driven few hundred kilometers after that. It seems that torque sensor is not working properly. I use Blevo, so it easy to see biker power. Sensor will give false readings. It is sensing either too much or too less torque. I think it more common to have too much power form motor.
I think it might be good idea change all bearing at same time, because I have to take at least these to bearings away. And maybe belt also. I saved my moneys at wrong place and I should have changed all bearings and the sensor at same time. I had to weld the casing also, because if was cracked.
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