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.
|2.6mm shim, 27.2 seatpost to 29.8 frame||708752011496||ST0226||210000031031|
|3.2mm shim, 27.2 seatpost to 30.4 frame||708752011526||ST0232||210000004009|
|4.4mm shim, 27.2 seatpost to 31.6 frame||708752012875||ST0244||210000009209|