Thomson h/bar clamp plate cracking – anyone else!?

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  • Thomson h/bar clamp plate cracking – anyone else!?
  • foxyrider
    Member

    Not here – think you might be overtightening them as the do have a specic max torque on the stem itself!

    woodsman
    Member

    I seem to have split the handle bar clamp plate on both my Thomson stems. I guess I must have been overtightening them, I didn't think I was overdoing it to be honest. I've got replacements on order btw. I know I should own a torque wrench and set them at 5.5Nm before anyone states the obvious.

    So, a common occurance?

    Premier Icon oxym0r0n
    Subscriber

    nope – not after years of cranking one on an SS either…

    Premier Icon singlespeedstu
    Subscriber

    Yep I've had one crack.

    They warrantied it for me.

    catfood
    Member

    I had one crack, but they only cost a few quid.

    I've had Thomsons on almost every bike I've had over the last 8 years or so and I've never even heard of it happening! Must be some serious over tightening going on!

    Premier Icon Radioman
    Subscriber

    no cracks after many years of Thomson ownership… I think their stems & posts are the best…

    woodsman
    Member

    Interesting – just borrowed a torque wrench and I was surprisingly close to the 5.5Nm recommended, if anything a fraction under…..the mind boggles, but as already said at under eight quid I won't be losing any sleep over it. More of a safety concern.

    woodsman
    Member

    Only the three of us…..checked a mates yesterday, and unbeknown to him his had a crack too!

    Think they are great products, just not as fit and forget as we may imagine, plus CRC must stock those little bits for a reason……….

    cynic-al
    Member

    Thomson in "less than perfect" shocker!!!

    Teh fanboys will be sweeping this under the carpet!!!

    over-hyped, over-priced .. nice kit but people have this idea that they are indestructible.. evidently not.

    tinsy
    Member

    Maybe you are not clamping it evenly a bit at a time on each bolt?

    Nothing is indestructable and your right they sell the bits for a reason…

    What they are very good at is keeping a very nice finish for a long time.

    PeterPoddy
    Member

    What they are very good at is keeping a very nice finish for a long time.

    Yeah, form over function is the way to go, eh?
    😉

    cynic-al
    Member

    Thomson fanboys outed!

    foxyrider
    Member

    Bigots rule OK 😉

    Premier Icon BigDummy
    Subscriber

    How big are the bolt heads, out of interest?

    I've just bought a Nuke Proof (£55), and was surprised that the bolts are 4mm allen key I think. That really makes you think about whether you should be swinging on them to do them up. 🙂

    tinsy
    Member

    Yeah, form over function is the way to go, eh?

    Nah not form OVER function but form WITH function.

    The Elite stem has the function, form and even safety built in, with the steerer clamp bolts not in the knee/nut zone… They should have used the same method on the X4.

    edit… woodsman, where is the plate cracked? Any pictures?

    (Mr MC posting) are you torquing them up in the right order? For any application where multiple bolts hold components flat youre supposed to work opposites, so if you numbered the bolts clockwise you'd tighten 1, then 3, then 2 then 4.

    First came across this re-fitting a cylinder head to an engine but it holds for all such situations.

    Personally never heard of ANY stem plate breaking.

    twohats
    Member

    I cracked one on my X4, correctly torqued up no less too.

    Got a new one under warranty.

    woodsman
    Member

    I'm quite used to the cylinder head torque sequence so, no that's not to blame. I'll post up a pic soon, once I've hosted it etc. Cracked in the middle, lateral, same on my other bike, also crack in the steerer clamp too (microscopic) same as a mates. Think I've been riding with it like that for ages. Only reason checked, was that I jumped a couple of flights of concrete steps after a eve ride, and something didn't feel quite right after – not as hardcore as it sounds, honest!

    clubber
    Member

    As above, you need to make sure that they're all torqued up correctly but arguably more important is to ensure that the face plate has even gaps between the face plate and the stem (ie left and right) on both top/bottom. It's very easy to torque the bolts properly but to have the face plate permanently twisted by not having even gaps – this will likely cause cracking eventually.

    woodsman
    Member

    Yeees, thanks but stating the obvious there clubber.

    tinsy
    Member

    Ferk, its not even come from and edge at all, looks to have started in the middle, rekon Thompson would be interested to get that one back, and I would imagine/hope give you a free replacement.

    To me, it looks like a flaw in the metal itself…

    clubber
    Member

    Yes it is but you'd be surprised how many expensive stems I see with uneven gaps (and by uneven I mean something like 0.5mm+ so not massively out of line.

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