Originally Posted by
ridethecliche
Sorry, I should have specified that the headset is a stronglight hinault and it uses roller pins and not 'ball bearings'. It might be the fork inside the frame, I sprayed frame saver in but didn't spray it with water first, though I did put a rag in and move that in there to get gunk out.
I wonder if the 30 year old Delrin material is breaking down, and releasing pigmentation into the bearing area?
Ride, if you are ever so inclined, I'd suggest disassembling again, cleaning the plastics really well with soap and water and a toothbrush, looking at the inner surfaces of the black plastic parts under the biggest available magnifying glass under REALLY good light, and see if you see any evidence of surface erosion or cracking. If so, old Bernard is toast, and you would need to get an A9 to replace it. A9s are pretty cheap at Bicycle Classics.
Road Fan