ULTIMATE USE SX 27.2mm Seat Post Shim
The USE shim system allows you to fit a seat post into virtually any frame size. Their shims are made to 100mm length and are longer than other shims on the market giving your seat post much better support inside the frame.Shims are available in Aluminum and Thermo Plastic, despite the latter being a lighter solution its material characteristics limit the thickness of the ID - OD measurements. Aluminum is used to achieve the thinnest shims as it is a more robust material.
Rolled Aluminum shim - the very thinnest shims are rolled from sheet metal. 25.4mm shims need to be so thin as they are etched down in acid to the correct tolerance and are too thin to anodise (show as silver).
Machined Aluminum shim - machined to very high tolerances from 6082 T6 Aluminum and then black anodised to protect from corrosion.
Machined Plastic shim - larger size shims are machined to very high tolerances from "filled" engineering thermoplastic UPVC. This keeps the weight down, as the shims get thicker.