The Problem Solvers Seatpost Shim is what you need when your seatpost is a little too small-diameter to fit tightly into your frame. It's made of light, durable aluminum and has a lip on the top so it won't slide down inside the frame during installation.
|1.4mm shim, 27.2 seatpost to 28.6 frame||708752009882||ST0214||210000010988|
|2.6mm shim, 27.2 seatpost to 29.8 frame||708752011496||ST0226||210000003378|
|4.6mm shim, 27.2 seatpost to 31.8 frame||708752012882||ST0246||210000004086|