hey there. building up an old flandria frame from scavenged parts, I've hit a problem I just can't get around. I installed an old (~mid 70s) threaded 1" Schwinn touring fork, using the headset from a mid 80s women's world sport, which fit just fine. however, when i went to install the generic japanese drop wedge bolt stem from the same bike it wouldn't fit. the stem is 7/8" in diameter, and the fork is 1" (outside diameter--I can't think of a good way to measure the inside diameter). both the stem and the headset fit the fork from the women's world sport, but the stem just doesn't want to go into the older, longer Schwinn fork I've installed on the flandria frame. it feels off by just a few fractions of a mm, tight enough that I don't want to just try hammering it in. could it be that the older fork is made of thicker steel, so the outside diameter and threading is the same, but the inside diameter won't allow a standard 7/8" quill? could it be some incompatibility between the ISO and JIS standards? I've been going off the infos on sheldo's pages below, which seem to say that any 1" Standard (25.4 mm) steerer should accept a 7/8"(22.2 mm) stem--what am I missing? thanks for your help.

http://www.sheldonbrown.com/gloss_st-z.html#stem
http://www.sheldonbrown.com/gloss_ha-i.html#headset