There is usually enough heat distortion to require builders to ream the seat tubes out to 27.2 mm.

Hey Sheldon, this brings up a question I've had in my mind for some time. Could an old Schwinn fork steerer tube be reamed out from the Schwinn-standard 21.15mm to 22.2mm to increase the options for usable stems, or would that be too much material to remove with a hand reamer? Say, for example, an old Tange fork on a Schwinn. The outside diameter of the steerer tube is the same as a "standard" Tange fork from the same time period, in fact everything is apparently the same, it's just that the inside diameter of the steerer is smaller, to give thicker walls, at the expense of a smaller diameter quill on the stem. Any input appreciated-

This should be doable. As long as you don't run the reamer too far into the steerer, to the butted section at the bottom, it should be just fine, but prepare to do a lot of sweating to remove that much material.

Sheldon "Reamer" Brown

Thanks, Sheldon-

Point taken.