Shimano Deore DX Headset keeps loosening itself

gt-arrowhead

Hey, I am posting this on behalf of my brother. He runs a Deore DX Headset and i found that it was loose when i squeezed the front brakes while stationary and rocked the bike back and forth. You could feel the play from the fork and the frame slightly. I tightened the upper bearing race down and tightened the lock nut on top of it. It was fine. After a 5-10 minute ride i came back to find that the headset had somehow loosened itself again! I have tightened it down many times but still the problem persists. i have no clue how this is happening and i didnt have enough time to open the headset up to try and find out what the problem was since my brother needed his bike.

Does anyone know what could be causing this loosening?
Here is the picture of the headset.

nicklouse

is the tabbed washer present?

read the info on threaded headsets on Parktools.

gt-arrowhead

I believe everything is there. My brother has never taken the fork off or undone the headset himself so it should be there. The parktools website doesnt really give much info on the threaded headset. Not for keeping it tight anyway

The Rookie

Between the lower adjuster and the upper locknut should be a washer, this will have a small tab sticking out the inside that runs in a vertical groove on the forks steerer, if it's not there or the tab has sheared off, you are wasting your time trying to fix it until you fit one.

gt-arrowhead

The Beginner wrote:

Between the lower adjuster and the upper locknut should be a washer, this will have a small tab sticking out the inside that runs in a vertical groove on the forks steerer, if it's not there or the tab has sheared off, you are wasting your time trying to fix it until you fit one.

Ahh. I know what you mean. My best guess would be that it might have been sheered off then. Next time i get a hold of my brothers bike ill have a look and put in a spare if its broken/missing. Thanks again beginner