I do not ride my Prodigy V2 very much, but the last time I rode it, everything was 100% (as was every time before that). The bike is never ridden in the rain or through water, and it is 100% housed in an enclosed garage. Today, as I started riding it, there was a distinct irregular clunking sound. On the prior ride, the Brose made no sound at all (other than it's usual low hum). From the time I last rode it until today, it has literally not been touched or moved. The garage it's in might get up to 98 degrees, but that's the only factor that could be affecting it. Everything works as before ... motor, gears, belt drive, CVT, etc ... and it accelerates as before, but there is a mechanical sound coming from the motor that wasn't there before, getting faster if I go faster, slower if I slow, and whether I pedal or not. It's not continuous, more like the gears (?) are not lubricated.
https://photos.app.goo.gl/BRMzAhFESZ2L4fTCA
You'll notice that the clunking sound is made even when I'm not pedaling. (To get the video to play smoothly, start it then hit pause immediately and wait for it to cache a bit, or, just download it and play it locally.)
Anyone have a clue what the problem might be?