The chris king bottom bracket conversion set has a 73mm threaded shell the chris king bb conversion kit 13 fits 73mm threaded bb shell 24mmgt22mm mountain cranksets required to work with the chris king threadfit 24 bottom bracket common cranks sram mtn bontrager mtn truvativ mtn zinn mtn adapts a 24mm spindle size to a 22mm spindle when you use the chris king threaded 24mm bottom bracket