[EDIT]Solved on July 10th : as WilliamT suggested, it was most likely caused by the motor mounting bracket rubbing against the chassis, due to the mounting nut being slightly loose, or the motor having slightly dropped since first install.
At least I reckon. In any case, if you hear the same noise, try tightening the motor assembly to the chassis and giving it another try. If it keeps crackling, try spurting a little WD40 like WilliamT explained, it seems to have worked for him.
Don't go full-conspiracy mode and try to disassemble the motor because you suspect there's a problem with the freewheel like I did
Recently, my Bafang BBS02 started making a crackling noise when pedaling with moderate force, even when the motor is off.
- The crackle always happens at the same spot (right pedal forward, pushing down).
- It doesn't crackle when using only the throttle, which leads me to believe that something is off with the pedal freewheel.
- However, I'm quite the newbie at diagnosing bafangs, and I was hoping some of you veterans could help me with your expert ears in case I'm mistaken.
- I intend on disassembling the motor some time this week to check the freewheel, but any alternative idea on the cause would be quite welcome.
Here's a 50 seconds video I recorded a few days ago to showcase this "crackling".
See 0:12 to 0:30 for the slow crackle demo
See 0:37 to 0:46 for the regular-speed crackle
Additional notes :
- ignore the high-pitch screech, it's my rear brake. I maintained it slightly pressed with a rubber band in order to generate a resisting torque that would emulate normal pedaling with some actual load.
- This motor has done about 1000 km so far, without a hitch.
- I usually run it at 260 W when cruising, with some spurts at 500 W uphill, way below its rated power.
- I don't have brake sensors and there's been a few times where I had to suddenly brake as the motor was running.
- I think it started that one time when I had to brutally brake while launched at 25 km/h. I might have been pedaling at the time, I don't remember.
Thank you for reading, feel free to say whatever comes to mind and have a nice day