Carbon frame bubbles??

Discussion in 'Cycling Equipment' started by jojoma, Jun 3, 2018.

  1. jojoma

    jojoma New Member

    Sep 7, 2007
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    I removed the bottle cage on my downtube and noticed a lot of corrosion from sweat, energy drinks, etc. It doesn't wipe off. Have you ever seen something like this. Is it something with the clear coat??


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  2. BrianNystrom

    BrianNystrom Active Member

    Aug 13, 2013
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    The first thing you should do is to contact the frame manufacturer and send them your photo. They're more likely to know whether it's critical or not than we are. You may also be entitled to a replacement frame.

    That said, it does appear to be superficial, though I've never seen anything like that on any carbon component. If the bubbles were following a weave pattern, I'd be concerned that it was stress delamination or infiltration of fluid into the the laminate from the cage bushing holes, but that doesn't seem to be the case here.
  3. Froze

    Froze Well-Known Member

    Jul 13, 2004
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    I think it's the epoxy resin deteriorating probably due to the manufacture doing a poor job around the aluminium rivnuts (known as bosses) with the epoxy. Usually with carbon they use a blind rivnut which expands or flairs once inside the frame to hold it in place and in doing so can perforate the carbon fiber frame, at that point it will act like battery does with galvanic corrosion between the bottle holder and the frame.

    This situation needs to be addressed by your warranty; is it something that will destroy your bike? That depends on how bad it will get, and it won't destroy the frame but it may allow those rivnuts to suddenly give up and you'll no longer be able to carry a water bottle, while some shops will glue the rivnut in place when that happens it's not an acceptable repair, if the bike warranty/bike manufacture fixes the problem, or if they don't fix it, you need to start using a dab of aluminium anti seize grease on the threads every year. These are stupid little things that are important for bike riders of CF bikes to know that the bike dealers don't tell you, I'm not even sure if most bike dealers even know about this stuff! So then it falls back on the manufactures who should be informing their dealers and customers of such issues and how to maintain the bike to prevent this crap.

    For fun you can read about the grease thing here:

    Of course when you tighten those bottle cage screws down make sure you know the exact torque recommendations so you don't rip the rivnut out of the frame, warranty won't take care of that.

    If you have an aluminum seatpost on that carbon frame you need to be removing that seat post once a year to prevent it from corroding onto the carbon fiber frame which will literally destroy your frame if you have to at some point in the future replace the seatpost. On those though you don't use the grease I mentioned, because all that grease I mentioned earlier is contacting the stainless steel threads of the screws with the aluminium threads of the rivnuts, placing grease on AL seatpost on contact with CF seat tube will prevent the post from staying in place and will slip, so for that you need to be using a carbon paste with about a once a year cleaning the post and the inside of the seat tube and reapply the paste. You can read about this more here: Again this is that fail to notify consumers either from the manufacture and or the dealer about these issues and how to maintain to prevent it.