Fsa the pig headset threadless headset with forged chromoly lower cup super oversized lower ball bearings and an aluminium top cap features12mm deep cup 6061 t6 upper cup chromoly crown raceupper stack height 16 4mmlower stack height13 6mmtotal stack height30mmreplacement upper bearing use part no 160 6120lower bearing part no 160 6725crown race use part no crowner no7 buy fsa components from chain reaction cycles the worlds largest online bike store