Carbone steerer damaged ?

TeamLaVaylie
TeamLaVaylie Posts: 5
edited April 2017 in Workshop
Hi,

After my first test ride and a check of my bike, headset am so on, I noticed this mark about 1cm on the top of the steerer tube, at the stem level.
Is that damaged or safe to keep riding with that ?
I wonder if the carbon quality is not involved in that change and suspect the stem pressure might have caused it.
I am thinking to go to the LBS to make sure it is safe. No marks or cracks further below.

https://www.flickr.com/photos/149539448 ... res/68J37A

Thanks for your advice.

John

Comments

  • sigorman85
    sigorman85 Posts: 2,536
    That sir is a cracked steering tube back to the shop it goes and the answer is I haven't tightened anything on the bike and if I did I would use the correct torque settings or bring it to the shop to do ...
    When i die I just hope the wife doesn't sell my stuff for what I told her I paid for it other wise someone will be getting a mega deal!!!


    De rosa superking 888 di2
  • noodleman
    noodleman Posts: 852
    Looks a bit like a manufacturing defect. Taking the stem off is a strange thing to do after a test ride though :?
    argon 18 e116 2013 Vision Metron 80
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  • jermas
    jermas Posts: 484
    edited April 2017
    Definitely cracked- don't ride! Did the steerer have a bung installed? If not, that probably caused the problem.
  • Thanks for your replies and advices, guys.
    I did the built-in by myself, but as far as I know, did respect the procedure and used a torque wrench.
    Wanted to add some grease to the bearings headset after the first ride, that’s why I had a look at it.
  • imposter2.0
    imposter2.0 Posts: 12,028
    You wanted to grease the headset after your first ride on a brand new bike? What bike is it as a matter of interest?
  • Can I ask...what torque setting you used?? and what fork is it??
    If you went the correct stem setting of 5-7nm that should NEVER happen..unless it is inferior carbon...Chinese frame etc...not saying it is, or that they are all bad...but that should not happen at correct settings etc
  • jermas
    jermas Posts: 484
    If you went the correct stem setting of 5-7nm that should NEVER happen
    Unless a bung wasn't fitted.
  • cougie
    cougie Posts: 22,512
    My money is on installation error there.
  • Used 4nm on my torque wrench for the stem tightening
    Super six evo no spacer above the stem as per cannondale manual
  • imposter2.0
    imposter2.0 Posts: 12,028
    Used 4nm on my torque wrench for the stem tightening
    Super six evo no spacer above the stem as per cannondale manual

    Was the bung inside the steerer when it cracked? If it was installed, I can't really see how it could have happened.
  • yes. the bung was inside
    the lbs told me today that by putting epoxy and the stem lower it should be fine but the fork will be sent for checking to the maker
  • mamba80
    mamba80 Posts: 5,032
    Used 4nm on my torque wrench for the stem tightening
    Super six evo no spacer above the stem as per cannondale manual

    any bike i ve built or owned has always had the stem fully clamped on the steerer and that requires a 5mm spacer above, means that the stem clamps fully onto the part of the steerer in-line with the bung.

    Anyone like to guess what Canondale will say?????
  • Then possibly the 'bung' was in the wrong position? if you dropped the stem it would be too high ( it should be at the same depth in the carbon steerer as the stem clamping bolts)
    The bung stops crush loads from the stem when this is tightened
  • keef66
    keef66 Posts: 13,123
    mamba80 wrote:
    Used 4nm on my torque wrench for the stem tightening
    Super six evo no spacer above the stem as per cannondale manual

    any bike i ve built or owned has always had the stem fully clamped on the steerer and that requires a 5mm spacer above, means that the stem clamps fully onto the part of the steerer in-line with the bung.

    Anyone like to guess what Canondale will say?????

    When I assembled my Scott CR1-SL their advice was no spacers above the stem. The suppled bung sits slightly proud of the top of the steerer so it would be pretty difficult to produce the kind of damage you've got.

    Other manufacturers use a bung that can be fitted lower down in the steerer, and then specify a spacer above the stem to prevent the steerer tube being clamped right at the top where it's unsupported and weakest.
  • jgsi
    jgsi Posts: 5,062
    Key thing is - do not over tighten those stem bolts.
  • jermas
    jermas Posts: 484
    Did you torque the stem bolts in increments? It's possible the damage occurred by tightening the top bolt fully, then the bottom fully -rather than in stages between the two.
  • svetty
    svetty Posts: 1,904
    Does look like over-tightening of top stem clamp bolt - suggesting either installation error or manufacturing defect - which I would suggest is possible but unlikely. The marks on the inside of the tube do suggest that the bung was correctly inserted as far as I can see........
    Assuming no warranty replacement your best bet is to shorten the steerer by cutting below the crack, then using a stem inverted to 'add back' the lost height. And make sure the bung is correctly placed when refitting the stem using a calibrated torque wrench.
    FFS! Harden up and grow a pair :D
  • on-yer-bike
    on-yer-bike Posts: 2,974
    Is there any reason other than aesthetics to not put spacers above the stem? It means you are only left with downward adjustment and non if you've slammed your slammed
    Pegoretti
    Colnago
    Cervelo
    Campagnolo
  • trailflow
    trailflow Posts: 1,311
    edited April 2017
    yes. the bung was inside
    the lbs told me today that by putting epoxy and the stem lower it should be fine but the fork will be sent for checking to the maker

    f**k*ng epoxy LOL ? What a bunch of jokesters. What if it wasn't fine though? and the steerer snaps clean off while your descending at 30+ mph and you loose all ability to steer and crash. And that results in your death (god forbid). Im sure they will take full responsibility of recommending you to 'risk' it because they thought so. They cant possibly know it will be fine by just looking at it. They're guess is a good as yours, anybody elses. The steerer is the most safety critical part on the bike. It's not something you just take a chance on. Especially when there is a clear crack like there is here. The damage to the carbon could extend further down inside thats not visible to the outside. Bike shops/mechanics are not safety specialists or composite engineers (but some seem to think they are). So please dont take their advice here. It's bogus.

    No way will Cannondale give the OK to ride that. It's terminal. I hope they just fast line the return process and replace it out of good will to get you on the road and riding.

    It's an unfortunate thing to happen with a brand new bike. Whether it was user mistake or a manufacturing mistake only you can know. But it can be replaced. Your life cannot. For the love of god. Do not ride that steerer. :o

    On to the installation of the stem. The only thing thats bugs me about using torque wrenches is, they may not be calibrated correctly. So i choose not to use them. And countless other people choose not to use them too. In all honesty bike bolts do not need to be done up very tight at all. They just need nipping up,not clamping down to the maximum so to speak. Ask a different bike shop to show you how to do it if in doubt. And with stem/handlebar bolts. Incrementally in very small movements and alternating as suggested above is the best way to do it, to even spread the load force. Then periodically check each and re-tighten each bolt a smidgen if they have loosened at all from riding.
  • onionmk
    onionmk Posts: 101
    Don't ride it! Get in touch with the manufacturer ASAP and hope to get it replaced. It might cost you, in which case you'll need to decide whether it's worth it ( considering the cost of the bike). I'd rather that than a broken collar bone or worse.
  • on-yer-bike
    on-yer-bike Posts: 2,974
    If the bung has made that impression in the tube then it must have been done up pretty tight.
    Pegoretti
    Colnago
    Cervelo
    Campagnolo
  • Lookyhere
    Lookyhere Posts: 987
    trailflow wrote:
    yes. the bung was inside
    the lbs told me today that by putting epoxy and the stem lower it should be fine but the fork will be sent for checking to the maker

    f**k*ng epoxy LOL ? What a bunch of jokesters. What if it wasn't fine though? and the steerer snaps clean off while your descending at 30+ mph and you loose all ability to steer and crash. And that results in your death (god forbid). Im sure they will take full responsibility of recommending you to 'risk' it because they thought so. They cant possibly know it will be fine by just looking at it. They're guess is a good as yours, anybody elses. The steerer is the most safety critical part on the bike. It's not something you just take a chance on. Especially when there is a clear crack like there is here. The damage to the carbon could extend further down inside thats not visible to the outside. Bike shops/mechanics are not safety specialists or composite engineers (but some seem to think they are). So please dont take their advice here. It's bogus.

    No way will Cannondale give the OK to ride that. It's terminal. I hope they just fast line the return process and replace it out of good will to get you on the road and riding.

    It's an unfortunate thing to happen with a brand new bike. Whether it was user mistake or a manufacturing mistake only you can know. But it can be replaced. Your life cannot. For the love of god. Do not ride that steerer. :o

    On to the installation of the stem. The only thing thats bugs me about using torque wrenches is, they may not be calibrated correctly. So i choose not to use them. And countless other people choose not to use them too. In all honesty bike bolts do not need to be done up very tight at all. They just need nipping up,not clamping down to the maximum so to speak. Ask a different bike shop to show you how to do it if in doubt. And with stem/handlebar bolts. Incrementally in very small movements and alternating as suggested above is the best way to do it, to even spread the load force. Then periodically check each and re-tighten each bolt a smidgen if they have loosened at all from riding.

    Yes say £400 (perhaps a week or two wages) for a new painted fork V severe gravel rash, broken wrist, collar/shoulder bone, facial fractures and dental bill?

    plus wrecked helmet, bike and wheels.

    No brainer really.

    fwiw i had exactly the same dilemma with a 2nd hand 585, very very faint crush marks on steerer, LOOK sold me a new fork, its never worth it.
  • Monty Dog
    Monty Dog Posts: 20,614
    Crush-damage by the look of it and it's highly improbable than Cannondale would say it's safe to ride. Doubt there's any case for warranty, but they might do a deal on a crash-replacement?
    Make mine an Italian, with Campagnolo on the side..
  • Rightarmbad
    Rightarmbad Posts: 216
    Who greases new headsets on bikes?
    Every good shop takes it apart and puts it back together again using grease and carbon paste where required.
    That stem was too high on the steerer, there is no way it was within the normal overhang for a steerer.
    Somebody has put an extra spacer under the stem that should not have been there. You needed the next frame size up or an upward facing stem installation.
    No decent shop would have set that up like that and if they did it is their responsibility to fix it.
    The markings for bolt torques are maximums not recomended.
    Use friction paste and do up to required amount to stop it moving and make sure stem gap is consistent, not tapered.
  • keef66
    keef66 Posts: 13,123
    Is there any reason other than aesthetics to not put spacers above the stem? It means you are only left with downward adjustment and non if you've slammed your slammed

    It's less about aesthetics and more about safety (and in the USA, fear of litigation)

    With a bung that sits flush with or slightly proud of the top of the steerer like mine, fitting spacers above the stem could mean that the lower part of the stem is clamping the steerer below the part supported by the bung, potentially crushing it or failing to clamp it securely. Neither of those is a good thing...

    The alternative would be to replace such a bung with one you can install at any depth in the steerer, and ensure you place it exactly where it's required to support the steerer against the stem clamp.

    Mind you, having tried to crush the offcut from my carbon steerer I can say the stuff is pretty robust. I think you'd really have to try hard to do what the pic suggests happened unless the thing had some kind of defect to start with, or the torque wrench was faulty.