I'm done with the paint and I started putting the bike together. The first thing I wanted was to put the headset on so I can assemble the forks to the frame.
And I ran into a problem. The fork crown race wouldn't fit. It was too small for the forks.
I was about to get a big hammer out but I decided to see how much of an interference fit there was. I was expecting something but not what I had.
.030" ballpark.. or NFW will I get the race on
I got my dial caliper out and measured the fork and it was 1.065" and I measured the ID of the race and it was 1.034"
WTH...F F F F.....This fork is a cheapie of Ebay so I measured another fork I have, a good Japanese Tange, and it was 1.066".
My headset is a Shimano 600.
So I put my mallets away and start digging into why I got parts that are not compatible.
And I find there are several standards of bicycle parts. There is an ISO, French, Italian, English and Japanese standards. The ISO is the most common today but 50 years ago it seems each country built bikes for their own domestic market and they were not compatible with another countries parts.
I'll make a long story short... I have two forks made to the Japanese standard and the headset (made by a Japanese company) is made to the ISO standard.
My choices were to get a new fork, or headset, or crown race.. or mill one of my parts to make it fit the other. Of the two it was easier to chuck the fork into the lathe and cut the crown seat down to the recommended .1-.2mm interference fit and thats what I did.
I would like to thank the late Sheldon Brown for giving me part of the puzzle
https://sheldonbrown.com/cribsheet-headsets.html
No fingers were harmed with the fork legs swinging around this morning.