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Torque for headset cap?

Ian.BIan.B Posts: 732
edited June 2010 in Workshop
I have had a lot of play in my aheadset (on a carbon steerer) after having dismantled and re-fitted it, and have tightened it very gradually until the play was eliminated - but I got up to 22Nm on the headset nut before I got to that point. That seems rather a lot - my bike maintenance manual suggests it only needs tightening fairly lightly and suggests about 3Nm! The wheel still turns very freely left and right and there is still a space between the cap and the top of the steerer. Should I be concerned about having overtightened it?

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  • muchallsmuchalls Posts: 87
    Insufficient spacers? If the cap is tightening against the fork steerer rather than the spacers this might happen ( I know, you do say there is space between the cap & steerer) but at 22Nm I think the expanding bit in the steerer would slip- may be worth checking it is not slowly rising up inside the steerer.
  • nicklousenicklouse Posts: 81,520 Lives Here
    there is no torque setting for pre-loading bearings. sounds like something is bottoming out somewhere.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
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  • muchallsmuchalls Posts: 87
    Quite. Just enough to remove the free play. If you had applied a preload of 22Nm to the bearings I don't think they would be running smoothly :D
  • Ian.BIan.B Posts: 732
    Thanks for your comments.

    @ muchalls, a good thought about the expansion bit slipping. I'll take a look. There are enough spacers, when the top is done up (to 22Nm) I can still see, through the gap between the stem bolts, that the steerer itself is still 1-2mm clear of the top cap, and can fit a screwdriver tip in the space. But maybe the expansion bit has slipped up in the middle above the steerer column itself.

    The front wheel does still swing very freely from side to side, with no hint of stiffness, so I think the bearings are running smoothly and not overtensioned.
  • hopper1hopper1 Posts: 4,708
    Ian.B wrote:
    Thanks for your comments.

    @ muchalls, a good thought about the expansion bit slipping. I'll take a look. There are enough spacers, when the top is done up (to 22Nm) I can still see, through the gap between the stem bolts, that the steerer itself is still 1-2mm clear of the top cap, and can fit a screwdriver tip in the space. But maybe the expansion bit has slipped up in the middle above the steerer column itself.
    The front wheel does still swing very freely from side to side, with no hint of stiffness, so I think the bearings are running smoothly and not overtensioned.

    If the star nut/expander had slipped up above the steerer column, then you wouldn't have any torque at all, as it would be free.
    I take it that your steerer has been cut so short, as to not have any spacers above the stem?
    If there is a spacer below the stem, take it out and put it on top of the stem, then tighten it all again, just to see if that works...
    Something is obviously amiss, here...
    Start with a budget, finish with a mortgage!
  • balthazarbalthazar Posts: 1,566
    The headset cap bolt is not an attachment "fixing" (it attaches nothing), it is an instrument for finely setting head bearing preload. WIth that in mind, a torque value for it is meaningless, but it is dependent on freely sliding stem and spacers, a solidly located expansion nut, and an appropriately cut steerer tube. If any of these is wrong then the procedure won't work.

    Another complication is that some headsets (my Campag Record one, for instance) use a split conical centralising washer to locate the top race, which aligns the bearings well but has a tendency to bind, making adjustment tricky. It requires a lot of back-and-forward adjustment, I find.
  • White LineWhite Line Posts: 887
    hopper1 wrote:
    If the star nut/expander had slipped up above the steerer column, then you wouldn't have any torque at all, as it would be free.
    Unless the friction was equal to the applied force from the 22Nm. :idea: So, say if you try torquing to 23Nm then it would slip a wee bit more.
  • muchallsmuchalls Posts: 87
    What stem? I ask as my Specialized has an eccentric shim to allow +/- 8-16' rise and I think I found that with 1 spacer short the cap only touched the steerer at one point.
  • Skippy2309Skippy2309 Posts: 426
    have you already tightened your stem to the steerer.... if you have no matter how tight you make the top cap its not going to adjust anything (made the same mistake myself) :P
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  • hopper1hopper1 Posts: 4,708
    Skippy2309 wrote:
    have you already tightened your stem to the steerer.... if you have no matter how tight you make the top cap its not going to adjust anything (made the same mistake myself) :P

    Good point, Skippy... :wink:
    Start with a budget, finish with a mortgage!
  • muchallsmuchalls Posts: 87
    Excellent point :D
  • Ian.BIan.B Posts: 732
    muchalls wrote:
    What stem? I ask as my Specialized has an eccentric shim to allow +/- 8-16' rise and I think I found that with 1 spacer short the cap only touched the steerer at one point.

    Ritchey Pro stem, Ritchey WCS carbon forks and Ritchey headset. This is the headset:
    3225331652_76883fbf9e_b.jpg

    Skippy - yes, the stem bolts were undone when tensioning

    I didn't get a chance to take another look last night - hope to do so this evening
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