SkyDog75

You'd both be correct if we were talking about threadless forks, where the stem clamps to the outside of the fork's steerer tube. But Chris is talking about a threaded fork and quill stem, where the stem goes inside the fork's steerer tube. A 1" stem will absolutely insert into a 1 1/8" fork and you can safely shim it for a proper fit.

The trick will be to find the right shim. There are 1" to 1 1/8" shims out there, but most of the ones currently available are designed for threadless stems. They're not long enough to engage the length of the quill and the wedge. Shims made for quill stems are longer, plus they have a lip at the top edge so the shim rests in place and doesn't fall into the steerer tube while you insert/adjust/tighten the stem. At a glance, I couldn't find any shims available on their own, but I did find them included with some stems or threaded/threadless adapters like this one.