Locknuts on a traditional headset - why no reverse thread?

Jim Newmark
Jim Newmark Posts: 151
edited August 2007 in Workshop
Over the years I have had real problems with the headsets of my bikes working loose over time, and having to be adjusted and tightened regularly. And then doused with Loctite. Why don't they have a reverse thread so that this doesn't happen?

Comments

  • aracer
    aracer Posts: 1,649
    Because you would have to size the steerer to the frame rather than having a generic size one you cut down. Also a solution to a problem which doesn't exist IME - do you have a tabbed washer between the cup and the locknut (if not that might explain your problems)? I have multiple threaded headsets and don't have a problem with any of them.
  • Jim Newmark
    Jim Newmark Posts: 151
    Yes, a tabbed or a flat on the lockwasher and corresponding steerer tube SHOULD work, but I don't think every manufacturer does this. Certainly my Bob Jackson with Stronglight headset has neither - just a plain washer and nothing on the steerer tube to correspond to them either. Is that odd? On the face of it it seems unsurprising that it works loose. over time.
    I am not a cycle engineer, but why wouldn't a reverse threaded locknut work better anyway? It would mean more fliexibility for the manufacturers as they wouldn't have to match their steerer tube to the headset they choose, with tabbed or flat lockwasher. I can't see why you should have to size the steerer to the frame in either case.
  • Garybee
    Garybee Posts: 815
    The thread is cut onto the steerer tube. If a left hand thread was used for the locknut the change from right hand to left hand would be critical. It would need to be at a specific point which could change if you changed the headset.
    Hypocrisy is only a bad thing in other people.
  • aracer
    aracer Posts: 1,649
    In any case, I think the time for your suggestion has passed!
  • rustychisel
    rustychisel Posts: 3,444
    You would need two different threads cut onto a comparatively thin steerer tube at a criticallly sized point, thus creating an engineering solution to a non-mechanical (ie installation) problem.
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  • Jim Newmark
    Jim Newmark Posts: 151
    Sorry, forget this stupid suggestion. I somehow thought that a reverse threaded nut would lock a conventional threaded nut on a conventional threaded steering tube by simply twisting it the reverse way. Of course that wouldn't work and I am glad that there are no visuals of my reddening face. No more on this please!

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