Originally Posted by FBinNY

Take a look at the photo below so we can all be working from the same playbook.



I suspect that you mean that the fork is stripped where the top race (aka top cup) goes, and you're trying to hold it together using the locknut only. That can work, but there's no way to lock the adjustment.

You do have a few workarounds if there's no other option. One would be to use a Loctite product to keep the locknut from unscrewing. Or you might try putting a hose clamp around the stem, pushed down against the locknut so it can't spin back up and unscrew. Those are just ideas for salvaging a fork that otherwise would go to the scrap man, but the "right" option is to do just that.

Originally Posted by JohnDThompson

Thread damage where the upper threaded cup engages is a result of riding with a poorly adjusted headset. This allows the upper cup to rock on the threads and eventually erode them away. The solution is either a replacement fork, a kludge such as FBinNY suggests, or melting brass into the damaged threads and cutting new threads in the brass. I have done this final method with good success.