Originally Posted by DiabloScott
Cinelli made (still make I think) quill stems for 26.0 mm. They're not marked any differently though so unless you get one in the box it'll be pretty hard to tell if it's a 26.4 or a 26.0.
i have what appears to be the same thing as a cinelli 1a with a 26.0 clamp diameter marked "1e." this may or may not be related to the different clamp diameter.