The fsa orbit xl2 1 18 headset is something of a classic in the fsa line up the orbit xl ii has forged and machined alloy cups top and bottom giving low weight and a high degree of accuracy a split crown race simplifies fitting and a pair of angular contact cartridge bearing promise long lasting performance fsa orbit xl2 1 18 headset features 118rdquo 36deg x 36deg acb upper bearing oversized industrial lower bearing forged chromoly lower cup 6061t6 upper cup indust