The insettm 1 is designed to fit a 1 18 steerer tubed fork and a 49mm internal diameter straight headtube that requires low stack bearing cups supplied with an all new bearing cap design the griplock is a multi piece bearing cap that utilizes a precision controlled split ring that improves steerer tube interface aluminum cups in 10 available colors house our legendary bearings all made in house in our portland oregon facility inset is the unrivaled upgrade for all riding styles check