I have double checked alignment and tension. I've tried different tensions - it changes the resonance a bit but never goes away. When I look at the pulley and feel the inner edges they look and feel poorly finished and rough instead of smooth.

 

I switched out to an Andrews 30T in the front and a 68T from a sportster (I think) in the back. It was a great set up. I just took that off and went chain drive a couple weeks ago. I have both pulleys, belt and spacers just sitting in my garage now. I could be talked into selling them pretty easily if you're interested......

 

Interesting... I initially agreed with Nemo's prognosis. It really sounds like an alignment issue. Is the edge of the belt frayed at all? Maybe a previously rectified alignment issue damaged the belt edge? At one point when I aligned mine I noticed that it moved the belt partially onto a portion of the front pulley that was previously unused. I wonder if something like that happened? You can tell if you look from the rear of the bike up the belt to see if the shiny part of the pulley is where the belt sits. If not, maybe there is some crud in the pulley?

Is it new issue that just presented itself, or has it always been noisy?

I've had the stock pulley and this one from J&P (I forget the brand), but neither of them made unusual noise...

 

No. I have the opportunity for intimate inspection of it while applying silicon grease to the edges after cleaning the belt. That makes the sound totally disappear for about 1K miles or so then it slowly comes back as it wears off. Its not easy to notice but I notice it. We all notice every little noise our Dyna's make don't we?

I haven't checked the front pulley - only have observed the crappy finish and inconsistent inner edge of the rear pulley.

Always done since 100 miles new. Removing the rear wheel, checking bearings and realigning everything I reduced it a bit. But only greasing the edges of the belt makes it disappear until that wears off. I know it is coming form the rear pulley. I can hear it even with the clutch pulled when crossing a bridge when the sound reflects back to me. Riding down the road it is very hard to hear.

I honestly think this stock oem pulley is not of high quality - or maybe well balanced. Maybe has excessive runout. I'd like to replace it with a more precision pulley - and probably a nicer looking one too.