I have an OEM 1999 Cannondale RT1000 stoker stem. The seat post clamp uses a shim to fit the 27.2 mm captain's seat post. The surface of that shim is scratched, so I cannot read the OD size of the shim. (See the photo.)
Can anyone tell me the OD size of the shim? I have tried to measure it, but it could be a few common sizes, depending on how hard I squeeze the shim together.