Strange but true: you should adjust the headset after fitting and tightening the stem (assuming it's quill) in the fork header, as tightening the quill can affect the adjustment of the headset.
@DickBarton started
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Strange but true: you should adjust the headset after fitting and tightening the stem (assuming it's quill) in the fork header, as tightening the quill can affect the adjustment of the headset.