Any question answered...

Do 1" steerer spacers tend to have the same external diameter as 1 1/8th" spacers, or are there only particular ones that do? I'm pretty sure the ones I have at the moment are, but as I didn't buy the bike new I'm not sure where they came from.

Generally they are smaller, but I suppose a very thick walled 1" spacer could be the same OD as a very thin walled 1⅛" spacer. I've got a 1⅛" tapered FSA spacer here (designed to be the last one under the stem) on which the thin end is the same OS as a 1" Chris King spacer.

Back to this fascinating conversation.

I bought some 1" spacers, and the external diameter is fine, they will sit relatively flush with the top cap, so the aesthetic considerations are sorted.

However, the diameter of the lip of the top cap is wider than the internal diameter of the spacers. By ⅛", obviously.

Should I just file out a bit from the inside of the top spacer so it plops in, or will it be okay just sitting on top and compressing from there?