Direto XR motorbike noise. Any suggestion ?

[eyoyofr]

Yesterday evening my direto XR suddenly started making some noise during a workout.
It sounds like a far motorbike. Like some pretty high rate friction somewhere.
Here is a video where you can hear the noise:
https://drive.google.com/file/d/1o3M6II ... sp=sharing
I opened the case and eveything was looking tight and clean. Would you have any suggestion ?
Should I perform a magnet spacing procedure ?
Thanks four your advices

[eyoyofr]

It looks like the tension pulley bearing is very lose and dead.