The thomson masterpiece seatback seatpost is thomsons ultimate seatpost it combines incredibly light weight with the characteristic strength and function of a thomson masterpiece seatposts weigh approximately 40 grams less than an elite seatpost of the same size while maintaining high strength and durability thomson accomplishes this weight reduction by machining the seatpost all over including the oval inner diameter theyre able to hold closer tolerances by machining than by extrusion a