Bravo if you've opted for a Chris King bottom bracket for your mountain bike frame. Now you more than likely need a BB conversion kit to set it all up. No problem. If you are running mountain bike cranks with a tapered 22-24mm spindle, such as certain SRAM, Bontrager, Truvativ, or Zinn cranks, and your bike has a 68mm-wide BB shell, you're going to want Chris King Bottom Bracket Conversion Kit #11. The Kit slips onto the crank's spindle and then into the Chris King ThreadFit 24 Bottom Bracket on your bike. If you have any more questions about which CK conversion kit to use, please let us know and we can help you out.