Rubbing greasy dirt where of the steerer against the headset bottom cup.
The sleeve which enlarges the steerer from 25.4 basic dimension to 26.5 for the crown race press fit is much longer than it needs to be, and the cup has been designed to clear only 25.4 on the reasonable assumption that the enlarged portion would be only slightly longer than the crown race. A bit of #judiciousfiling should solve the rubbing.
This worked in the end! Been committing this week with the bike, finally no noise, no rubbing, good setting of the headset! Extremely pleased, thanks for the help!
The sleeve which enlarges the steerer from 25.4 basic dimension to 26.5 for the crown race press fit is much longer than it needs to be, and the cup has been designed to clear only 25.4 on the reasonable assumption that the enlarged portion would be only slightly longer than the crown race. A bit of #judiciousfiling should solve the rubbing.