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	How much should it move? On my bass, it moves about the thickness of a credit card. You want it to at least move a little bit. If it doesn't move at all, then you need to loosen the truss rod. How much is too much? The quickest way to tell if the right amount of relief is in your neck is to lower the strings.		If after lowering the strings, the notes buzz only above the 12th fret, then there's too much bow in the neck. You'll need to tighten the truss rod. If after you lower the strings, the notes only buzz in the 1st 5 frets then your neck is too straight. You'll need to loosen the truss rod. If after you lower the strings, the notes buzz all up and down the neck, the neck's fine. Your strings are just too low.