Baseplate or crown race call it what you want. Chris King calls it a baseplate. These things last forever when in use, just like the rest of a Chris King Headset. In fact, King headsets are often moved from one bike to the next. This is generally where the need for this 1 18in Stainless Steel Baseplate arises. Of course, they sometimes get lost in the shuffle or forgotten and sold on an old fork. They can also be damaged by improperly removing them from the old fork. In any case, this is exactly what you'll need to mate a fork with a 1 18in straight steerer to a Chris King 1 18in NoThreadset.