i have several bikes and they all ride differently when riding "hands free" (HF). some are difficult but not due to headset adjustment or damage. i'm not talking about wobble here, just the amount of sensitivity to weight induced steering input. worst is a '79 Trek 710 touring frame. very sensitive. best is a Gary Fisher '95 Tassahara. completely stable. i imagine it has something to do with rake and trail. tire width IME has an influence too. also found i benefited from a bit of refining in my HF riding technique.
in one case, things improved greatly when the tires "squared off" after a few hundred miles.
Last edited by hueyhoolihan; 11-29-13 at 11:19 PM.