Originally Posted by
dddd
Glad to hear that the OP got this sorted.
I had a similar situation after meticulously rebuilding the old Shimano 600 headset on a 1981 Bianchi just a few weeks ago. What was odd was that I adjusted the headset with a dummy stem in place to simulate the expansion of the quill in the steerer. I had it perfect and with the locknut good and tight, but after the first ride the headset had a loose adjustment! No, the locknut hadn't loosened at all, but apparently the bearings settled into their grooves a little better(?). Weird is all I can say, but I can say that I've seen these things happen, somehow.
Perhaps the cups or crown race finally settled more fully onto their press fit, even though the old bike was used and I hadn't disturbed the press fits at all during the rebuild process.
On the other hand, In 50 years I have come across a couple of headsets that were poorly machined such that one pair of the properly-assembled cups and cones rubbed slightly because of zero clearance, even with the correct size balls in place.
Oh, and on my own PH501, those headset components were HEAVY in the extreme, which is odd in that the entire bike weighs only a bit over 22lbs iir.
I dont know how much more heavy this stock headset is than any other headset i have used. IT seems pretty simular to just about every other headset i have used. A few grams in either direction isnt noticeable at all. I figured if the headset didnt go back together or if it was worn i would replace but i didnt take the crown race or cups out to measure them. I figured more than likely they were some weirdo french sizing and id just be wasting my time trying to find something else. I am glad these worked out. Like i said...had they not......the whole thing would have came apart and i would have started searching for a replacement. I have had really good luck with Tange Levin headsets. The price is right and they are quality. I just dont know if these are standard sizes in this peugeot. If i had my choice this is what would replace the stock headset.