Originally Posted by goldener
why does it matter? isn't a 25.4 diamter a 25.4 diameter regardles if its on the flat or on a bulge?
no, as sammyboy said, it's narrower in the grip section:
7/8" or 22.2mm for MTB (and cruiser) handlebars
15/16" or 23.8mm for drop bars
brake levers are sized accordingly