Headset play

errorist Posts: 169
edited January 2012 in Workshop
I have a problem whereby when I tighten up the stem bolts onto the steerer tube (to the recommended 5nm) I start to get play in the headset. I know the headset preload bolt is tight enough because when I loosen the stem bolts the play dissappears. However for obvious reasons I am worried about leaving them at a looser torque.

Any suggestions gratefully accepted!


  • I am not sure how you can check for play if the stem is not tightened. Likely is that you cannot check properly, whilst once you can (with tightened bolts) you do experience some play. My advice is to tighten the top nut further, you can't do any damage... if you still have play, then you have a problem with your headset... likely to be badly installed or (less likely) damaged
    left the forum March 2023
  • keef66
    keef66 Posts: 13,123
    Sounds odd. I cannot see how tightening the stem clamp would induce play in the bearings, unless the clamping force is sufficient to deform the steerer.

    Is it a carbon steerer? If so, does it have a solid bung type thing for the top cap nut to screw in to? And is there a spacer above the stem?
  • errorist
    errorist Posts: 169
    Yeah I thought it was pretty odd!

    It is a carbon steerer and the star nut & bung etc all look normal. I have also tried using both a spacer and no spacer above the stem.

    Maybe I am overtightening the bolts. Not sure my shonky old torque wrench is that accurate!
  • sungod
    sungod Posts: 16,852
    if it's cf, then usually there shouldn't be a star nut, but a bung

    if the top of the bung is too close to the top of the steerer it can foul the underside of the top cap so that when you tighten the top bolt it doesn't actually preload the bearings, but if you tried a short spacer above the stem it should rule that out

    if the bung isn't tight, it might be slipping as you do up the top bolt, often the bung has a recess for a large hex key to tighten it in the steerer

    the bung should extend at least the full length of the steerer that is subject to the clamping force of the stem

    5Nm shouldn't be enough to distort the steerer, if you might have over-torqued it a *lot* then i'd have a very good look at the steerer for any sign of damage, it's not a good place for a failure!

    how about...

    if the top of the headset isn't quite level (due to damage, incorrect install, contamination, etc.) it might cause some odd effects, if it meant the stem was at a slight angle when loose then as the stem bolts tighten they'd tend to force the stem's axis closer to the steerer axis, but then the stem would no longer be resting evenly on the headset and it might cause the play you are finding

    had you changed anything when you noticed this?
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