Sounds like my rear d is grinding. Can I open it and clean it and regrease?
Me to my riding buddy, "Want to ride this afternoon?"
Him, "I can't. I have to chop this guys foot off at 2".
Have you replaced your chain recently? Make sure the chain is routed properly through the pulley wheels.
No, but I will check it out. You can feel a slight vibration in the rear d and dampen it by touching it. Makes me think it is something internal, but i'm no mechanic.
Could be a blown bearing in one of the pulleys.. Unhitch your chain, or remove the pulleys around it, and give them a spin in your hand.
It's unlikely, but given the symptoms, a possibility.