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Carbon frame damage

Discussion in 'Bicycle Mechanics' started by Riceman, May 19, 2008.

  1. Riceman

    Riceman Warming-Up

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    Hi all.
    I haven’t posted on here for a while. Looking for some advice where to get my bike checked. I have a specialized Tarmac SL. While out riding at the weekend I noticed my gears were not changing smoothly so when I got home I put the bike on a bike stand and proceeded to spin the rear wheel up while I adjusted the gears, Well the worst thing happened, the bike slipped off the stand and the stand went through the rear spokes and wedge past the rear drop out taking some of the clear coat and paint off the frame.
    My Question is: Does anyone know where I can take the frame to be checked or repaired I live In Fukuoka. I took my bike to my local bike shop who called Specialized, but they said specialized will not check it and the shop said it should be ok. Should be ok is not really good enough as I don’t want to fail on me while going down a hill. Any help would be most appreciated.
     
  2. Edogawakikkoman

    Edogawakikkoman Maximum Pace

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    Chips on my carbon frame are repaired with nail polish. Luckily my frame is red.
    Fibreglass may be an option for larger areas. (surfboard repair kits).
    Ask around at cyclingforums and see what other people say too.

    A friend of mine doesn't want to by carbon because he says it's not strong however I disagree. Carbon may chip but if it bends it bends back into shape. If Aluminium bends it bends.... My carbon frame has had 2 huge crashes and is still holding its shape. I'm sure it would have been scrap metal by now if it were an aluminium frame.

    Hope you find the best solution to repair your baby. It must have made you cry when you did it...

    :nosweat:
     
  3. Freeride39

    Freeride39 Peloton Leader

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    No bad at all

    It seems like what happened to your carbon frame is just cosmetic. I wouldn't panic, I think it's going to take a lot more than just falling off a stand with a chip to take it out of service. I see if you crashed and the frame took a hard thrashing, but other than that, sounds cosmetic. I notice a lot of people out there love putting carbon frames down, stating that they aren't strong enough (everybody's inner professional).....LOL. Good enough for the Tour de France, good enough for me. If what you just explained is enough for a full frame MRI, I guess all carbon frame bikes need to be recalled.....LOL. Don't worry about it, believe me the engineers have put the material through more rigorous stress than a frame stand drop! Plus I am pretty sure the paint doesn't add much to structural integrity, but damn it can hurt some pride for your ride.....LOL. Ride on brotha:rolleyes:
     
  4. Ash

    Ash Warming-Up

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    Can you also put nail polish on aluminium?

    Ash
     
  5. Polymer Head

    Polymer Head Warming-Up

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    The solvents used in nail polish are commonly isopropyl alcohol (rubbing alcohol) and acetone (very strong odour and excellent at dissolving many plastics and paint). It's no surprise to find acetone as a nail polish remover (the labels are so hard to read).

    Since 'aluminium' usually exists with a coating of aluminium oxide, the chemical resistance of this oxide layer extends to alcohol and acetone but not to the paint on the 'aluminium' frame. I'll stick my neck out and say you can put nail polish on 'aluminium.'

    There are many grades of aluminium alloy depending on composition, heat treatment and hardening processes used. Hence, 'aluminium.'

    As a note, the higher the grade of aluminium alloy the less chemical resistance it has due to the other elements present eg. copper, silicon, magnesium, manganese. Since, I assume, nail polish will only be applied to very small areas, the solvent will most likely evaporate rapidly, especially aided with a hair dryer - try not to ignite the solvent.
     
  6. WhiteGiant

    WhiteGiant Maximum Pace

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    Resident Chemist...?

    Hello Polymer Head,
    I didn't actually know that!
    I enjoyed chemistry very much in senior-high-school, and I always thought of "acetone" based chemicals to be quite rough on plastics - including carbon.
    I never imagined they would also be hard on "alloys".
    I'm aware of the different mixtures of metals in most alloys (some for rigidity; some for lightness, etc.)
    Are there any (metals) that are particularly susceptible to acetone?
    This is a serious question!
    My bike IS aluminium, by the way.
    Travis
     
  7. Polymer Head

    Polymer Head Warming-Up

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    Travis

    After rereading my post, you're right, it is not as clear as I thought. Sorry about that.

    Nail varnish/polish will not harm your aluminium alloy frame as the oxide layer is able to resist acetone, alcohol, methanol. As for any alloys which are susceptible to acetone, I don't know any. The hairdryer reference was for those cautious ones (have come across academic papers on metals and acetone and recently corrected a paper on activated carbon and acetone, erm... lets' get back on track).

    The confusion appears to come from the last paragraph. Copper is added as an alloying element (some series) but the alloys are processed to prevent corrosion e.g. Duralumin, more specifically Alloy 2014 (a development of) is coated with pure aluminium or aluminium with 1% zinc, Alloy 7075 undergoes a complicated heat-treatment process to minimise stress-corrosion cracking. This means, nail polish should not harm an expensive aluminium bicycle frame, knowing the above.

    To allay or increase your doubts. What qualifies me to say all this? Not much really, especially as my knowledge of metals is rudimentary. I'm a Polymer Engineer that, amongst other things, studied the interaction of perfluoropolymers with certain grades of aluminium used in the harsh processes of the semiconductor industry. They are renowned for very clean processes to prevent wafer contamination - from all sources. In the lab, I wash and clean series 5xxx and 6xxx alloy jigs with acetone and methanol. Some were also soaked for 24 hours in acetone. After inspection with the naked eye, no apparent corrosion was observed (no pitting whatsoever, though they were never put under an optical microscope or a scanning electron microscope).

    Considering the knowledge we know so far, the small areas involved, that the solvent will evaporate quickly and based upon my experience of handling aluminium and acetone, I am confident in saying that nail polish will not harm your aluminium frame.
     

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