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.
|2.0mm shim, 27.2 seatpost to 29.2 frame||708752009899||ST0220||210000024429|
|3.6mm shim, 27.2 seatpost to 30.8 frame||708752012899||ST0236||210000038060|
|1.8mm shim, 25.4 seatpost to 27.2 frame||708752024380||ST0518||210000034144|