Chris King BB Conversion Kit #21
You've finally made the jump and bought a Chris King Threadfit 30 bottom bracket to upgrade that tired stock BB that your frame arrived with. Now you have a clean, 73mm threaded BB shell staring you down and your 30mm spindle RaceFace crankset just waiting to turn in anger. The last piece of the puzzle is a Chris King BB Conversion Kit #21, which slips onto the crank's spindle and then into the ThreadFit 30 bottom bracket on your bike, allowing everything to work in perfect harmony.