Hope pf46 press fit stainless bottom bracketthe external bottom bracket is available with two different bearing options. All common systems are covered with this upgrade unit, making it ideal for shimano, race face and truvativ extra conversion kit required.the machined aluminium cups hold either full stainless steel cartridge bearings, or ceramic bearings in stainless races. These custom, swiss made bearings are double sealed which gives much greater life span than stock units. They are also replaceable. The bearings are made by ina and have been designed to run directly on the crankset axle, without the use of shims or spacers again increasing life and reliability. We use a non contact, free running labyrinth seal to protect the bearing externally, and the machined aluminium centre tube is sealed internally with o rings. The unit is suitable for 68 73mm shell width's with an 83mm width version and a specific road unit.specificationfits bb92, bb89.5 and bb86.5 framescups pressed in and held in place by a screw in centre tube stopping any movement or play usually found in press fit framesstainless steel or ceramic bearingseasily serviced, replaceable sealed bearings and external labyrinth sealcompatible with any 24mm axle cranksspecific fitting tool made by hope required for fitmentbuy hope pf46 press fit bottom bracket from chain reaction cycles, the world's largest online bike store.