Headset help please!

backo
backo Posts: 167
edited August 2013 in Workshop
Quite baffled by the play in my headset and why i cant fix it

Have stripped the headset/fork cleaned and regreased. When i pre load the headset by tightening the bolt on the headset cap, there isnt any play whatsover.... Perfect. As soon as i tighten the stem bolts to finish off the job with a torque wrench the headset becomes loose again?!?!?!

How can tightening the stem bolts produce play in the headset?

Baffled

Have repeated the procedure a few times now and still the same result.

Comments

  • majormantra
    majormantra Posts: 2,094
    It can't.

    Is it an expander plug (fork bung) or starnut? If the former it may be pulling out of the steerer.
  • backo
    backo Posts: 167
    Its not the bung version . Its the star nut

    Really bizarre
  • turnerjohn
    turnerjohn Posts: 1,069
    headsets take a while to bed back in once taken apart (even more so with a load of grease in them), torque it down, turn the bars to and fro a few times and get it seated then torue the preload bolt up again...should notice movement. Check it again after a ride as it may need torquing down again...once settled it will remain tight
  • maddog 2
    maddog 2 Posts: 8,114
    sounds like the stem itself is not flush/square down on the headset. When the stem is tightened it's moving up very slightly, creating play. I'd check the steerer tube itself to see if there is any damage, and possibly fit a very narrow spacer underneath (1 or 2mm) so that the stem isn't contacting the steerer in exactly the same position as previously.
    Facts are meaningless, you can use facts to prove anything that's remotely true! - Homer
  • backo
    backo Posts: 167
    Thanks for advice, will try them out

    not sure why I would suddenly need a spacer though...the bike is 7 years old and nothing has changed in terms of spacers, stem etc... the current headset is about 6 months old. I cant see why anything would change in terms of adding spacers but will give it a whirl.

    Strange how despite the pre-loading which is removing any play. how tightening the stem can create space to allow movement....only thing I can think off is maybe a fault in the bearings themselves.

    Going to strip down, re-inspect and try the advice from here...fingers crossed I don't have buy another headset
  • crankycrank
    crankycrank Posts: 1,830
    Also make sure the stem clamp bolts are just snug enough to create a slight resistance on the steerer. If your stem is loose enough to wiggle on the steerer tube while you set the preload the stem can be slightly off from being square against the preload cap. When you tighten it up it can leave a very slight gap.
  • backo
    backo Posts: 167
    maddog 2 wrote:
    sounds like the stem itself is not flush/square down on the headset. When the stem is tightened it's moving up very slightly, creating play. I'd check the steerer tube itself to see if there is any damage, and possibly fit a very narrow spacer underneath (1 or 2mm) so that the stem isn't contacting the steerer in exactly the same position as previously.


    many thanks for your help, stuck a 2mm spacer on top of stem and below headset cap and it has worked a treat.

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