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  • Stem slipping – just keep tightening?
  • letmetalktomark
    Full Member

    I have a 50mm Thomson stem that has a 5nm torque recommendation for tightening to the steerer.

    Torquing to this I can still turn the bars under pressure whilst holding the wheel.

    I’ve tried 6nm but still the same. 😕

    Now I have just gotten myself a torque wrench so in the passed I wouldn’t have given it a second thought and just tightened further but …..

    So is something likely to be up or should I just add some more torque 😆

    iainc
    Full Member

    have you degreased the top of the steerer and inside of stem ?

    legend
    Free Member

    That’s kinda normal, is the headset coming loose or the bars moving when riding? Standard post crash (especially mid-race) procedure for straightening bars is to just yank them round.

    I’ve got a similar problem but the headset is coming loose when torqued to the correct spec. I’m reluctant to over-torque though due to a carbon steerer

    stumpy01
    Full Member

    Have you got another stem to try at the same torque?

    As above, stem & steerer mating surfaces de-greased?

    It would depend how much pressure you are having to apply when holding the front wheel to mis-align the stem, as to whether it would be a problem or not….

    If it’s a gentle twist then I’d say it’s not right. If it’s a real heave on the bars while clenching the wheel between your legs as tight as you can, then it’s probably OK.

    scotroutes
    Full Member

    What’s the steerer made of? Some carbon assembly paste might help.

    Rubber_Buccaneer
    Full Member

    I had the stem slipping to allow the headset to come loose with a Renthal Apex stem. I cleaned the steerer and stem then reassembled with a smear of carbon assembly paste (despite everything being aluminium) and have not had any further slippage in the last couple of rides. Still only torqued to 5Nm (using a Teng torque wrench that I trust rather than a torque key)

    letmetalktomark
    Full Member

    Cheers all.

    No grease present but will give it a wipe over to be sure and then perhaps try another stem.

    Steerer is a standard (are you allowed to use that still) alloy one on a Pike.

    philjunior
    Free Member

    You really want to make everything super clean with some IPA. You could also use some carbon grip paste to help things along, but you need to be careful you don’t end up with it getting where it shouldn’t and making things wear away that you don’t want to wear away.

    FWIW I was quite surprised to see my 3T road stem had a specified torque of 13Nm on the stem clamps – I didn’t dare go that tight (I went to 12Nm). That was M6 bolts though, so the force from that would be equivalent to an M5 at about 10Nm (still “a lot” – probably quite close to yielding the M6 bolt even in quite high grade steels.)

    Your steerer should be fine a reasonable amount beyond 5Nm but I would be concerned about the bolts themselves and the stem if that’s what’s specified (it’s not unknown to see cracks on Thomson stems).

    letmetalktomark
    Full Member

    All sorted.

    Wilcos brake cleaner to the rescue.

    All tickety boo now.

Viewing 9 posts - 1 through 9 (of 9 total)

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