I just finished my 1983 Trek 600 restoration. The headset adjusts with a catch. As tight as I make the top nut, the actual headset cup at the top can still be backed off. In other words the top locknut does not seem to be tightening against the cup nut. I think the problem could be that the groove washer is binding. Anyone ever have an issue like this?
Garth Libre in Miami Fl USA