-
OR turn the bars very lightly and rocking back and forth with no weight on it
Strange, you’d really think it must be something headset related with this.
Does the fork have a star nut in the steerer or is it one of the removable wedge type ones like the Hope head doctor?
Sometimes the removable ones can be a bit shit, if it moves slightly in the steerer, it can prevent the headset from pre-loading correctly.
It's a Geometron, I'd be surprised. I've checked headtube for cracks, checked welds and can't see anything. It only does it on hard fork compressions, OR turn the bars very lightly and rocking back and forth with no weight on it