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  1. #1
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    Anyone have a broken carbon frame they want to let go of?

    Hi, I come from the marine industry and have a solid amount of composite boatbuilding experience as well as friends who work in both NDT and a composites lab for a major manufacturer of non-leisure CF components. I am distressed that the cycling industry has taken the position of "replace and destroy" rather than repair with carbon frames (by and large - many excellent shops like Appleman, Calfee, Spyder, Ruckus do just the opposite). I am looking for some frames in any state of damage that have been replaced and are no longer needed on which to experiment. I don't plan on attempting to return any of these to service, but rather to x-ray them, repair them and then stress the repairs to see what breaks first. Just want to figure out what's really going on and see if there's an alternative the wood chipper. Lotta black magic being tossed around that doesn't seem to add up. I'm sure for companies like Trek, Spesh, Salsa it's more of a liability question than anything else of course and getting the damaged frame off the road or trail is more important than potentially saving a couple hundred bucks. I just have a bunch of cloth and resin and access to a carbon lab so let's play.

  2. #2
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    Yup, I'm sure liability is the main reason no one (companies) repairs carbon frames. Actually zI don't think any bike companies repairs metal frames either. That's left to third party hired by the end user. Maybe custom builders will. I only have one frame that I would be sad if it cracked and would be worth saving. All my others would be a retire and replace.
    I thought back to friends and aquantances and recall some metal frames being repaired, but was smaller companies.

  3. #3
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    It seems to me that the repair of such frames is not worth it, because the place where the frame was broken remains weak and can cause many problems in the future. For this I think it's better to change to a new one!

  4. #4
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    False. Like, super, super false. What would make you think that the repair would "remain weak"? The repair could very easily be made considerably stronger than the original layup at a cost of a few grams weight. The danger in doing so would be passing the stress along to a different area of the frame without the repair flexing (absorbing any of the stress) and breaking the frame somewhere else. It's not unusual for a repair shop to warranty the carbon repair for the life of the bike.

  5. #5
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    Quote Originally Posted by Hops143 View Post
    False. Like, super, super false. What would make you think that the repair would "remain weak"? The repair could very easily be made considerably stronger than the original layup at a cost of a few grams weight. The danger in doing so would be passing the stress along to a different area of the frame without the repair flexing (absorbing any of the stress) and breaking the frame somewhere else. It's not unusual for a repair shop to warranty the carbon repair for the life of the bike.
    You are correct. I know a frame repair guy with a past similar to yours. He tested his frame repairs with a reputable MFG and they found his repairs to be stronger than the original frame, at the cost of a few grams.

    There are some big shops that are well known that may have improved their processes, but in the past have done real hack jobs.

    It is a detail oriented process that cannot be rushed or have corners cut if you intend to repair it to original strength.

    Sent from my Moto G (5) Plus using Tapatalk

  6. #6
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    Good points tfinator. I started this thread because I sent a $3,000 fat bike frame from a very highly respected builder to my colleague to x-ray and to give me his opinion and I was blown away - his comment was that it looked like a five year old made it. Unfairly overstated, no doubt, but illustrates the fact that carbon bikes are still in the infancy stage in the grand scheme of things and are probably set to get better over the next few years at a logarithmic rate. I'm just astonished that so many of these frames are so very repairable and yet are written off and tossed out.

  7. #7
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    Quote Originally Posted by Hops143 View Post
    Good points tfinator. I started this thread because I sent a $3,000 fat bike frame from a very highly respected builder to my colleague to x-ray and to give me his opinion and I was blown away - his comment was that it looked like a five year old made it. Unfairly overstated, no doubt, but illustrates the fact that carbon bikes are still in the infancy stage in the grand scheme of things and are probably set to get better over the next few years at a logarithmic rate. I'm just astonished that so many of these frames are so very repairable and yet are written off and tossed out.
    Dude, like anything that is made by humans quality can be a huge variance. And being that carbon production is a hugely labor intensive there are many places for shoddy work. And as far as replace vs repair, its no different than any other industry. And on that matter it again comes down to who repaired it and how seriously they took it just like during the manufacturing of the frame itself. Bottom line, its the people involved that determine the result.

    If you do more x-ray testing, try one of the chinese frames. I'd be very curious to see their consistency with their open mold designs.

  8. #8
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    Here is your new best friend...

    A carbon repair guy from aerospace,, lots of great articles...

    Tech Articles

  9. #9
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    Quote Originally Posted by Hops143 View Post
    Good points tfinator. I started this thread because I sent a $3,000 fat bike frame from a very highly respected builder to my colleague to x-ray and to give me his opinion and I was blown away - his comment was that it looked like a five year old made it. Unfairly overstated, no doubt, but illustrates the fact that carbon bikes are still in the infancy stage in the grand scheme of things and are probably set to get better over the next few years at a logarithmic rate. I'm just astonished that so many of these frames are so very repairable and yet are written off and tossed out.
    yes.. this, a milion times this..

    there are a lot of crappy carbon frames out there.... Trek's OCLV frames are awesome for a reason....



    This guy has some you-tube videos of cutting open Enve rims with voids the size of peanuts in them..

    Tech Articles

  10. #10
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    Quote Originally Posted by JamesPM View Post
    This guy has some you-tube videos of cutting open Enve rims with voids the size of peanuts in them..

    Tech Articles
    And they charge an arm and a leg for the luxury of them voids.

  11. #11
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    Quote Originally Posted by Hops143 View Post
    Good points tfinator. I started this thread because I sent a $3,000 fat bike frame from a very highly respected builder to my colleague to x-ray and to give me his opinion and I was blown away - his comment was that it looked like a five year old made it. Unfairly overstated, no doubt, but illustrates the fact that carbon bikes are still in the infancy stage in the grand scheme of things and are probably set to get better over the next few years at a logarithmic rate. I'm just astonished that so many of these frames are so very repairable and yet are written off and tossed out.
    Not that many are written off or tossed out that offer easy repairs. There are now a ton of repair shops that do it. If so many were being written off, those wouldn't exist.

    Certain types of crashes (high speed, high force involving cars) can internally mangle a carbon layup such that no repair is possible.

    Cracks at the bb, headset, and some other places are much much harder to repair. So a lot of repair guys won't do it, or just charge a lot and make it cost prohibitive.

    As another poster said, the quality depends on the company. IME Ibis frames are (or were) bomb proof. Mine had 7 repairs done in it's life time... And it ain't dead yet.

    Also, you should quote people in your replies otherwise they may never see what you say.

    Sent from my Moto G (5) Plus using Tapatalk

  12. #12
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    I've got three broken carbon frames, but I may get them fixed!

    Carbon reapair is absolutely viable, and no shortage of good companies to do just that.

  13. #13
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    Carbon repair is pretty common, and pretty easy. The factories build these things paper thin, it's not hard to make a strong repair, even using basic/diy methods.

    It takes talent to make a seamless repair! But that's not really the strongest way to go.

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