There is no other explanation.
I am trying to install the fork on the frame. Put the crown race on it.
It goes down the tube fine until the final inch or so. The tube gets a little thicker, by millimeters, almost negligible but enough to make it difficult.
If I try and force the crown race onto it, the crown race will actually be a little too big for cups, due to expansion.
What so I do? This is a modern 1 1/8 fork. Do I put a spacer there? Get a different headset? Shave some material off of the fork (looks very difficult)?