Mr Pig said:People keep talking about the high-low adjustments on the dérailleurs and I don't know why. If the limit screws were set correctly when the thing was installed it's unlikely you'll need to move them again. All you need to do is adjust the cable so that the chain sits straight on the gears.
Failing that the cassette is worn though it usually kicks rather than being noisy.
youngoldbloke said:Check the chain has been threaded through the jockey wheels and cage correctly, and is not riding on/outside the folded guide on the cage. (It has been known!)