I had the same thing happen. The inside ring on the pulley is just tack welded on. I'm not sure what caused yours or mine to fail but have been told I probably caught a small rock just right in between it and the belt and it popped it off. It was covered under warranty. They replaced the pulley and also replaced the wheel that was damaged by the ring bouncing off it for who knows how long??? No one to blame or worry about. Just one of those weird things.

 

I had to deal with the same thing 4 or 5 years, back but with my hearing by the time I discovered it I didn't have but a quarter of an inch of belt left. The funny part is, that quarter of an inch belt carried me thirty miles to my indy. I just chalked it up to "well crap happens."

 

i've seen this happen before and have seen guys just weld the ring back on. i don't know why harley doesn't put more weld on that ring. this is nothing new to their rear pulleys and they know it has been a problem.