The ceramic pf46 24mm spindle bottom bracket from hope features machined aluminium cnc cups with replaceable ceramic bearings that are swiss made and double sealed to ensure a much greater life span this is a press fit bb that is designed for use with a 24mm spindle diameter and a 46mm diameter bb the bearings are made by ina and have been designed to run directly on the crankset axle without the use of spacers or shims which also helps ensure longer life and reliability the bearing is prot