Greetings!

I have stripped the threads on my seatpost clamp and went to an lbs to
find a new one (seatpost = 27.2). The clamp sold to me wouldn't fit
around the seatpost due to the machined ridge at the top that prevents
sliding down the seat tube. I probably could have gotten it on the
seat tube (the clamp was slightly out of round and would have required
some wanking) but I couldn't have gotten the seatpost in it.

The frame is columbus foco and seems very thin at the clamp area. Does
anyone know what size clamp would be appropriate (if the tubing were
0.4 mm at that point, I would suspect a ~28.0 mm clamp would be
appropriate).

The ridge on the old clamp appears to have been ground off. Maybe do
that with the clamp that will fit the seattube?

TIA and Happy Thanksgiving!

App