Originally Posted by Andrew R Stewart

These cartridge bearinged headsets generally wanr the cartridge riding on the beveled face and not the bearing's ID or OD. Otherwise why add cost and grind that bevel. The ID and OD should be sliding fits over the crown seat and within the head tube (or cups) ends.

The split seat ring is often what is locating the upper bearing's top side. The split ring can "float" along the steerer to allow for preload adjustment and the split will let it keep the bearing coaxial to the steerer as it compresses around the steerer. Is there another conical ring with a split in it in the packaging? Andy