Originally Posted by Bianchi84

There is a thin nut that seems made specifically for that hanger. Look at the underside of the hanger - there is probably an angled indentation designed to accept the nut. It has to be lined-up right to fit over it. You might have an incorrect nut. The setup should be: headset race is installed, portion of steerer tube protruding. Maybe you'll need a spacer on top of it, maybe not. Thin Lock-nut goes on top of that. Adjust headset with nut "angles" set to accept hanger to sit straight. Still steerer tube protruding just enough to accept hanger. Shove on hanger. Put ferrule in hanger. Tighten pinch bolt. I guess you could let the hanger be installed sitting on top of an incorrectly sized nut, but the recessed nut, I think helps keep the collar from rotating.