Fsa power drive bottom bracket bb 8420replacement bottom bracket for power drive splined cranksets the stiff forged hollow chromoly spindle is supported by a pair of sealed industrial cartridge bearings additional weather protection comes from double snap seals features forged hollow scm4130 chromo spindle industrial 6002krs cartridge sealed bearings with oversized diameter 316in balls cold forged aluminium cups double snap seals for water and dirt protection weight 325gbuyfsa compon