I have a problem with the seatpost on my Masi bike (Gran Corsa Premio). I recently bought a new seat, a Selle San Marco Blaze Pro with Ti Rails. When fitting to the seat clamp, the rails are a couple of mm narrower than the clamp, so I have to push the seat while tightening the single clamp bolt. However, the seat is now slipping back slowly, no matter how tight the clamp bolt is.
Do I need a new seatpost (not sure why the clamp doesn't fit the rails - I thought the width should be standard?!) or can I buy a new clamp for the seatpost. The seatpost is branded Masi, and looks to be carbon or carbon wrapped.
A small piece of rubber cut from an old tube and fitted between the rail and the seat clamp may help. Otherwise...twin bolt seatpost is the way to go. It cured the problem for me.
