>>1359377>stem clampOlder flat bar bikes use 25.4mm, older road bikes use 26mm. Newer bikes in general use 31.8mm
>handlebarsFlat bars use 22.2, road bars use 23.8
>steerer tubeOld bikes use 1in, newer ones use 1⅛in. This one is probably the only universal standard
>seat postsAt least three sizes common -- Don't remember them.
>axlesOld road bikes used 126mm. 130mm is the new road standard, with 135mm on mountain bikes (I think). Things may get wider as we get more gears
> bottom bracketsBSA is the most common threading which comes in a few widths I think. For old frames you better hope there's specs online or some kind of identifying marks on the BB itself.
