Originally Posted by
Harold74
Purpose made headset wrenches have worked great for me in the past. Crescent wrenches... obviously not, especially on black locknuts.
My headset locknut is mirror-polished aluminum alloy, the surface of which is no doubt considerably more fragile than your black locknut. I used an adjustable (“Crescent”) wrench, using electrical tape on the jaws, to tighten it.