Originally Posted by
hueyhoolihan
i agree TheromionicScott...
centering shouldn't be a problem. the two upper races, the one on the adjustable cup and the one that is pressed in, in concert with the bearings should center everything, taking its alignment from the pressed in cup. it would help as mentioned if the reamed cup, formally known as the "adjustable cup"
, was a tight sliding fit with the steerer tube though.
Yes, it's not about centering. The bearing will float to center and ride squarely unless pressed unevenly.
But it is about a fit tighter than you can achieve pressing down the length, which is why crown races are always pressed onto a raised set. Without a truly tight press fit, or a compression ring, the headset will click and creak until you can't take it anymore and go back and do it right.