I find the best way is to sit on the top tube (a la Froome), apply the front brake and then rock the bike backwards and forwards. If there's any play in the headset you'll soon feel it.
@Brommers started
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I find the best way is to sit on the top tube (a la Froome), apply the front brake and then rock the bike backwards and forwards. If there's any play in the headset you'll soon feel it.