If your mountain bike came with a straight steerer tube you can use this bearing adapter to put in a tapered steering tube and run a different fork.
Tapered fork to non tapered frame adapter.
How to install a tapered fork into a no tapered head tube using hope pick n mix head set cups music by.
This will work with any bike with a pressed bottom cup that is 1 1 8 although i believe this no longer allows for frame warranty check with bike manufactur.
Your bicycle s headtube must have an inside diameter of 44mm or larger in order to use any tapered steer fork.
Fitted the headset and the adaptor crown race to the fork and works perfect.