I've taken this up with Selle SMP. I don't really understand their reply. I'm attaching a photo of my seat clamp. Is this not a standard clamp?

Their reply is, "The clamp is not like the SMP seat post recommendation because the clamp is an arc instead of being straight."

There is a diagram of the required clamp at http://www.albabici.com/selle/tech-i...smp-saddle.htm under "Seat post recommendations" halfway down the page. #3 says, "the clamps must be the same shape as the outside surface of the saddle frame, so that there is good coupling with a large contact surface (fig. 3)"

I honestly can't see the problem with my clamp. It has fit every other seat I've put on it. Selle SMP also suggets sanding or tape, but I don't get why this should be necessary.