Danger of carbon fiber wheels delaminating

Discussion in 'Road Cycling' started by cyclintom, Nov 29, 2018.

  1. cyclintom

    cyclintom Well-Known Member

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    Indeed, it certainly is stupid to have to point out that you and Brian are saying things that never happened.
     


  2. Froze

    Froze Well-Known Member

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    AND YET YOU HAVEN'T ONCE, NOT ONCE, EVER PROVEN WHEN ASKED WHAT WE SAID THAT YOU SAID WE SAID FROM OUR POSTS! YOU HAVE NEVER ONCE SHOWED ANY POST, OR ANY SENTENCE THAT EITHER BOB, BRIAN OR MYSELF WROTE TO SHOW THE WORLD WHERE WE SAID THE THINGS YOU DREAM UP THAT WE SAID, AND WE HAVE ASKED YOU REPEATEDLY TO DO THAT AND SO FAR NOTHING FROM YOU JUST YOUR STUPID ONGOING MADE UP STORIES.
     
  3. cyclintom

    cyclintom Well-Known Member

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    Didn't you notice directly above when Brian said, "No Tom, YOU were having trouble with pinch flatting when installing tubes and I offered some insights into how to prevent that, and did so in a polite and respectful manner.".

    Evidently he was as polite and respectful as you because he never even posted on that comment line. This is called false memories. This is from getting angry because someone won't agree with you so you misremember what you did. And yet all he had to do was look on the string to discover he'd never even posted. I could have chased your similar comments down but I assumed you were far less likely to allow that sort of thing to happen to you.

    This sort of thing went way too far with Brian saying that because and installation video had a peculiar looking spot in it which was no doubt caused by a gust of wind as he came to a stop proved the power meter useless. Instant power means nothing at all. It is average power over some period of time.

    If you recall I posted the video of that Masters race with appended power readings and he had instantaneous readings above 2,000 watts and every lap in the same area he was going over 1,200 watts. Even CampyBob was saying that the only thing that counts is average power.
     
  4. cyclintom

    cyclintom Well-Known Member

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    New discoveries. I don't know if you remember it with the others making every possible attempt to change this thread from a warning about the dangers of the full carbon TUBELESS rims delaminating with almost no pressure into the Heckle and Jeckle show.

    The first set I had gotten had one wheel that seemed to be fine. But the second wheel when pressurized went WAY out of true and as I released the pressure it came back into true. They sent me a new rim to put together myself but it turns out that it is extremely difficult to build these carbon rims because the nipple bed isn't even and the factory used torque measurements and not thread length to get them both; to true and get the extreme spoke tension these wheels require with minimal spokes.

    In any case. Today as I cleaned up the garage I came across the rim that had gone out of true. I have looked it over carefully and hadn't seen any delamination that was visible. This time I thought that I would tap on the rim to see if it had delaminated inside where it couldn't be seen.

    So I tapped around the rim and sure enough, there was a hollow sounding spot on one side of the rim that demonstrated that it was the same sort of delamination only not taken to such extremes.

    So I will shut down my efforts to rebuild that wheel since it was about half built. The hubs are the cheapest you can get but they are also of perhaps the highest quality I have come across including Campy Record and DuraAce. I can spin the front wheel go away and come back 5 minutes later and it is still moving. The rear is similar though the ratcheting mechanism steals most of the energy pretty rapidly. I can't remember my experiences with King hubs but he does have a great reputation and extremely expensive hubs so I'd give him the benefit of a doubt.

    Now the construction of a clincher rim is significantly different from a tubeless rim and having a tube inside puts forces against the bead entirely different than a tubeless rim. And my experience with the carbon clinchers from China have been GREAT. What's more there are videos all over Bing and YouTube praising them as well. So I wouldn't worry about having the same sort of problems with the VERY cheap and highly worthwhile clinchers from China.

    But as of now steer very far clear of the tubeless wheelsets.
     
  5. dabac

    dabac Well-Known Member

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    Well, sure. The more consistent the parts, the easier and/or faster it is to build up a wheel.
    But extremely difficult?
    Maybe for you I suppose.
    As a general statement - no.
    All you have to do is pay more attention to what's HAPPENING than to what you DO, and the wheel will still come together without drama.
    It'll be slower, take more patience. That's all.
    But "extremely difficult" - I don't think so.
    I've laced 36H hubs to 28H and 32H rims in cross patterns.
    There's no way your nipple bead varied more than the spoke length mismatch of those builds.
    And I'd never claim that those builds were "extremely difficult" unless they'd come with a time limit.
    Tedious and time consuming, sure. Difficult - no.

    Does this mean that you think that the performance of a bearing in its unloaded state is good proof of its performance under operating conditions?

    In what way?

    How does it do that?
     
  6. cyclintom

    cyclintom Well-Known Member

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    I have built many, many wheels. You don't seem to have a good grasp on what is occurring with the carbon wheels. They are low spoke count aero spokes. They have to be tightened to very high torque. You cannot align the wheels while building them unless you take them to very high torque first to pull the 2-cross spokes into alignment. This is not something you can do slowly and it will all come together. It is something that requires the building machines that tightens all of the spokes at once to high torque.

    I have no doubt that you can construct one of these wheels by hand but this isn't some child's play as you seem to think it is. I have one down in the garage if you think you can do it.

    I can build a 3 cross 28 spoke MA-2 rim in 30 minutes. And another 15 minutes to true it. Telling me that you can do better than that makes me wonder what sort of equipment you have.

    As for a bearing spinning like that - if you have a standard bearing that spins for 20 seconds and comes to a stop and they another with the same wheel and tire that spins for several minutes you're damn straight it means that it will perform better under load because it means the balls and races are more true.

    I explained that in the last posting of yours. These sorts of problems are called "closed conduits" and the shape of the conduit changes the psi applied to any area. It is difficult to understand but all you need to do is see it and you understand.
     
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