Originally Posted by
dddd
I've seen a crown race split, so whenever I encounter a seemingly tight fit onto the fork crown seating area before it has moved close to the crown, I go back and simply use sandpaper on the OD of the crown race seating.
If replacing cages with loose balls to make a used headset run smoother, never "remove one" ball from a filled headset cup or the balls will have the degree of freedom to find their way into the dents in the highest-load zone of the races.True full-compliment is the way too go but of course test the assembly for smooth rotation as soon as the top cup or cone is snugged down. The same goes for any ball bearing assembly except for freewheels and perhaps freehub bodies.
Interesting point about using "full compliment" of loose balls, I always stuck with the time-honored (old wives tales for old mechanics?) method of "fill and remove 1 ball"...I may have to re-think now. I also have installed a lot of standard crown races and being lazy I don't always measure FIRST (and I own micrometers but ALWAYS use a digital caliper on bikes), so if I find I'm trying to ram a 26.4 crown race on a 27.0 crown race seat (or more likely a 27.1) I am forced to stop cause it's always apparent that it WILL NOT GO. That's not close to a press-fit tolerance and the amount of pounding to force-fit that mis-match would probably damage the fork if I persisted in trying. I don't try.