I have a small issue with my threaded headset and for the life of me cannot figure out how to solve it. Would be very thankful for any tips! I built up a classic road bike last year and at the time asked my LBS to install Cane Creek 100 Classic headset. I had no issues with it for a while but recently have noticed that it tends to come loose after every little while, making my bike rattle when braking. I have had threaded headsets before and have always managed to tighten them properly. Yet, in this case I cannot seem to lower the upper lock-nut enough to keep the threaded top-cover in place. There appears to be a small washer between them with a hex screw slot. There are also small threads still visible beneath the lock-nut , but it just does not go lower. At the moment the threaded top-cover has so much room that at the uppermost position there is at least a couple of millimeter of play in it. What's the trick here? Should I find a hex wrentch small enough and try to loosen up the washer? Should I try to find another washer to install in-between? Cheers!