So I have a weird problem. I'm putting a 1 1/8" stem on a threadless 1" fork using a shim. I have no problem setting the preload but I can't tighten the top bolt of the stem because the top cap literally fits inside the stem. The shim is about 5mm shorter than the stem, so I'm preloading against the shim instead of the stem. Do I just need to get a 1 1/8" top cap, or is there a longer shim I should be using?