Thomson Masterpiece C The Masterpiece C is an evolution of the industry standard seat post – a Toray fiber and nano epoxy dream come true. The post features our new Ti hardware and our trusty alloy clamp, everything you’d want in a modern carbon post. The quality you trust – now in carbon fiber for the prized bike in your collection. Specification​ Toray fiber and nano epoxy. Ti hardware. Trusty alloy clamp. 7mm x 10mm Rail Clamp. NB: Standard clamp that this post has is suitable for 7x10 rails only. ​