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  1. #76
    Senior Member Cateye's Avatar
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    Quote Originally Posted by johnny99 View Post
    This is one of the Boston Globe's photos of the year (http://www.boston.com/bigpicture/201...rt_2_of_3.html).
    Can someone explain what happened to Mark's front wheel?

    It was a prototype rim that is inflated with helium........it got a puncture.

  2. #77
    Type 1 Racer rydaddy's Avatar
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    Quote Originally Posted by Motobetird View Post
    Fatigue testing, still today, is a grey area in the polymer industry. I took a class on non-metallic manufacturing processes. The carbon fiber is reasonably well documented and straight forward, its the reinforcing plastic coating which throws the curve balls. Atmospheric pressure, humidity, applied force, and numerous other conditions all play a role. Zipp probably does top of the line testing, and still does not have all of the variables accounted for. The bicycle industry at this level constantly walks the line between weight vs. load.
    Quote Originally Posted by wens View Post
    I suspect the problem was creep, not fatigue.

    :facepalm:
    Not fatigue OR creep. Facepalms all around...

    0:53 of the video shows it all. It's called impact.
    Last edited by rydaddy; 12-17-10 at 12:16 AM.

  3. #78
    Senior Member Halebopp's Avatar
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    Quote Originally Posted by rydaddy View Post
    Not fatigue OR creep. Facepalms all around...

    0:53 of the video shows it all. It's called impact.
    He's talking about that light fixture anectdote, not the crash.

  4. #79
    Senior Member Halebopp's Avatar
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    And the "facepalms" every other post are annoying me. One step above "lol".

  5. #80
    Senior Member Motobetird's Avatar
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    Post #38
    -The scary thing is that they are starting to make airplane wings out of Carbon Fiber Reinforced Plastic (CFRP). Apparently manufacturers are confident in their fatigue testing at this level.


    Manufacturers being confident? I dont think an R&D guy at that manufacturer would say it's safe. It's probably some business guy's interpretation of what the engineer told him. If/when failure occurs, the engineer will get the blame and the business guy will waltz off to another project, and cause more problems there also.[/QUOTE]


    -- I forgot...on the scale of airplanes vs. Bike components the weight savings from going to CF from metal is in the 1,000 s of lbs opposed to bicycle components which is weighed in grams. Because of this they are able to use much more material. Basically, the 2 are not similar enough to compare because of the scale.

  6. #81
    Senior Member Motobetird's Avatar
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    Quote Originally Posted by wens View Post
    How is this relelvant? And what the hell is apoxy? And since I'm guessing the light fixture was only undergoing static loads I suspect the problem was creep, not fatigue.

    :facepalm:

    -- Epoxy, not apoxy. Brain fart due to my pronunciation. Epoxy is the shiny stuff they coat carbon fiber with. Which is why the technical name for what we just call "carbon fiber" is carbon fiber reinforced plastic.

    --- And as for the creep, I believe you are correct. It's been a while since the schooling days.
    Last edited by Motobetird; 12-17-10 at 01:36 AM.

  7. #82
    Senior Member 7bmwm3gtr's Avatar
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    Do people like to over-analyze things?

    It's almost like those people who bring mathematical formulas and reasoning into "Which came first, the chicken or the egg"
    http://dbcyclingblog.blogspot.com *Last updated 2/25/2014*

  8. #83
    Type 1 Racer rydaddy's Avatar
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    Quote Originally Posted by Halebopp View Post
    He's talking about that light fixture anectdote, not the crash.
    I don't know if you understand, I am talking about the impact the Zipp wheel made perpendicularly with Cav's wheel. Creep and fatigue are completely unrelated. A very high point load along the weak axis of the rim caused the rim to fail.

    Quote Originally Posted by 7bmwm3gtr View Post
    Do people like to over-analyze things?
    So your "analysis" was a failure and now you choose to change the subject?
    Last edited by rydaddy; 12-17-10 at 08:34 AM.

  9. #84
    Typical Scum brianbeech's Avatar
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    Quote Originally Posted by 7bmwm3gtr View Post
    Do people like to over-analyze things?

    It's almost like those people who bring mathematical formulas and reasoning into "Which came first, the chicken or the egg"
    This has been solved: http://www.msnbc.msn.com/id/38238685...ience-science/

    "It had long been suspected that the egg came first but now we have the scientific proof that shows that in fact the chicken came first," said Dr. Colin Freeman, from Sheffield University's Department of Engineering Materials..."

  10. #85
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  11. #86
    Senior Member
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    Thanks for posting video Quel! Wow. That's gotta hurt.
    __________________________________________
    "You spend the whole time afraid you're weak, but clawing every second knowing that if you can just shut your mind off and turn the pedals 1 more time you're going to be 1 pedal turn closer." -- Psimet

  12. #87
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  13. #88
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    Quote Originally Posted by RacerOne View Post
    I can't believe the skid mark the guy on the far left at 00:32-36 leaves on the ground. Ouch.
    Seb Hinault



    i was bored

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