Before going farther, shift to high and see how much room there is between the chain and dropout along the back and top where the chain is on the sprocket. If there's about 1-2mm clearance, then there's no need to respace the hub because it isn't the problem.
It's possible that the hanger is bent or twisted. If you have a yardstick try this. Shift to high, put the yardstick against the wheel vertically just behind the cassette. If all is right, the vertical section of the chain will be parallel with the edge of the yardstick. I suspect that it won't be which is why it's brushing the hanger as it leaves the jockey wheel.
Also the yardstick will give you a good frame of reference so if there is any change in the chain angle coming to the sprocket you'll see it. If the chain does "wobble" on the way up, then either the jockey wheel is damaged (or it's hub is worn out) or possibly the chain itself has a few bent or twisted plates. Either way, the good visual reference of the yardstick will help make the problem obvious.
Also if it's touching at the very back of the dropout (9 o'clock) then it's simply a case of a bent dropout, but this is usually obvious to the eye.
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FB
Chain-L site
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Last edited by FBinNY; 04-05-13 at 08:00 PM.