Fsa megaexo mtb bottom bracket bb 9050megaexo bottom bracket for use mtb nbd megaexocranksets features oversize cartridge bearings forged alloy and cnc machined external cups alloy center sleeve w double o ring seals sizes english threading 6873mm width bc 1 37in x 24t weight 110gbuyfsa componentsfrom chain reaction cycles the worlds largest online bike store