My '09 ultra is making a squeaky chirping noise from the rear wheel. It only does it after the bike runs for a few miles, then it gets progressively louder, is is my belt or a bearing?

 

It is my understanding that the squeak is coming from the rubber isolate for the slip-ons.

 

Spray some WD in the rear rubber muffler mounts and see if it stops? If it does replace them it's a no brainer. If it doesn't stop check you belt.

 

It only does it when the bike is moving. It's clearly an issue with the wheel.

 

Check the belt is tightened correctly. A too tight belt will make it squeak. Also inspect the pully for wear.

I had same issue and replaced the pulley and cured the squeak. You can moisten the belt with soapy water and then run for a few miles to see if the squeak goes away, when it dries the squeak will come back, but at least you will know it's a belt isuue

 

It could be the rubber muffler isolators. Some grease or lube spray and ride it again will rule that out. The other thing it can be is the rear wheel bearings. But I see you have a 2009 like me. If the belt and rear pulley are original and have a good amount of miles it could be they need to be replaced. Especially if it only makes noise when you let off the throttle. My belt wasn't damaged and had all the teeth but they weren't exactly round any more. The front and back of the teeth were flattened. And the rear sprocket is only aluminum and mine was obviously worn. The front sprocket is steel and doesn't really wear. Now it is silent.

 

I took a look at the pulley and it is all chewed up. I'm thinking this could be the issue.