Sheldon Brown not only accumulated and subsequently shared a broad depth and breadth of knowledge about bikes and cycling, he wrote with such clarity it was striking.

In his memory and with all due respect, then, please note the correct spelling of his name.

re th OP: road bar clamp diameters (new) vary between 25.4mm and 26mm. Then there is the quite common 31.8mm. So there. That should make it clear as mud. No, seriously. Hie thee to your LBS and buy a pair of bars that fit. You'll pay a little more, maybe, but apples and awareness never came free anyway.