Catastrophic failure Niner Carbon Fork - Page 3- Mtbr.com
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  1. #401
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    It probably broke and caused the crash, particularly since it was a recall fork, but the story does say it may have broken and caused the crash. It could have broken during the crash too. Like he fell down and slid into a curb or other immovable object hitting at the front. It's hard to say with so little information.

    As far as being able to tell if it's going to break, if it does so at the steer tube crown union (guess) it's probably pretty hard to spot, unless it starts to feel loose.

  2. #402
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    Quote Originally Posted by PatrickK View Post
    Holy S...... That is absolutely tragic. How do you tell if your carbon fork is fine or not?
    Yes, very sad indeed. Kind of a freak occurrence imo.. Millions of carbon forks being abused daily and rarely do they break (no I don't need photos of broken forks )

    I guess you can take it out of your head tube and take a look at the steer tube... Do you have the 2008 Cervelo fork in question? They describe it in the article very well...

    .02

  3. #403
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    Maybe we should start a new thread for the recalled cervelo fork.

  4. #404
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    Quote Originally Posted by Moementum View Post
    On a related note a road cyclist recently was killed when his carbon fork failed.

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    ... not to mention, the article says there was a possibility of collision with something in the road or another vehicle, and they were still investigating.

  5. #405
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    Quote Originally Posted by rydbyk View Post
    Yes, very sad indeed. Kind of a freak occurrence imo.. Millions of carbon forks being abused daily and rarely do they break (no I don't need photos of broken forks )

    I guess you can take it out of your head tube and take a look at the steer tube... Do you have the 2008 Cervelo fork in question? They describe it in the article very well...

    .02

    No but I have a Niner, Ritchey Comp carbon and a Trigon fork. My Trigon makes a creaking sound from time to time but I looked at the steerer and apart from an even surface around the crown which has an additional layer on top of carbon I have not noticed anything. It is really hard to see anything. It might be Cane Creek headset. I use this particular bike for road biking.
    “You can always count on Americans to do the right thing - after they've tried everything else.”

  6. #406
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    Well, now I'm nervous!

  7. #407
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    Quote Originally Posted by DLtoker View Post
    Well, now I'm nervous!
    Find a different sport that is safer.

  8. #408
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    This post is a nonsense. Time to shut it down. I don't work for Niner nor sell their stuff and of the 5 people I know with their forks they are massively strong. We do drops, enduro races, rock step and as I have said before I run into a concrete carpark. Fork is perfect.

  9. #409
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    Wow, hope he gets better. And this is why I don't really want to ride carbon fibre anything. Steel just bends, usually won't snap!!
    -Eric
    Keeping the hardtail dream alive, one ride at a time.

  10. #410
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    Nice to see the gutless anonymous Rep posters are at it again.
    Get some balls and say what you want to say in the thread so that I have a way to reply.

  11. #411
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    Quote Originally Posted by TR View Post
    Nice to see the gutless anonymous Rep posters are at it again.
    Get some balls and say what you want to say in the thread so that I have a way to reply.
    Nah. Even though you are way down under, I'm afraid that you may call me out on in regard to my own stupidity.

    I've been riding my Niner fork in rocky stuff and I weigh 225lbs. No drops. It loosens from time to time, but otherwise, no problems. I do worry occasionally, but I had those rare concerns with my WaltWorks.

  12. #412
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    hope I don't end up like your buddy after buying this. But i'm still super pumped to try it


  13. #413
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    So the ugly, idiotic, status symbol forks are prone to breakage.

    How so very

    Catastrophic!

    Get well soon, dude.

  14. #414
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    I'm gonna try mine out on trail for the first time this weekend. I hope it will take a 2.4 Ardent.
    Also, I hope that it don't.....well, you know.

  15. #415
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    Glad I went all steel with my rigid...
    "Those who wander are not always lost"

  16. #416
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    Quote Originally Posted by [wahoo] View Post
    Glad I went all steel with my rigid...
    Yup, Steel forks never bend or break!

  17. #417
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    Ouch that must of hurt!

  18. #418
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    Quote Originally Posted by OneBadWagon View Post
    Yup, Steel forks never bend or break!
    I've seen one bend, but it didn't break. Thankfully it wasn't my fork, and the bikes fork bent after the rider bailed and the bike took a tumble into a river canyon, lol.
    -Eric
    Keeping the hardtail dream alive, one ride at a time.

  19. #419
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    Quote Originally Posted by OneBadWagon View Post
    Yup, Steel forks never bend or break!
    Yes they bend, but I have never heard/seen one snap off. I think it would have to be a pretty big failure for them to break completely in two.

    Hope the OP's friend is alright.

    On the topic of Niner's reputation, it seems like they have done everything to assess the issue. 1 extreme failure out of 4500 forks that are out there seems like it was one of those strange random occurrences. Niner is on my list of dream bikes.
    Last edited by [wahoo]; 05-26-2012 at 04:40 PM.
    "Those who wander are not always lost"

  20. #420
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    Quote Originally Posted by Ray Raton View Post
    I'm gonna try mine out on trail for the first time this weekend. I hope it will take a 2.4 Ardent.
    Also, I hope that it don't.....well, you know.
    The Ardent will fit. Actually, it fits really easily. There's plenty of room to go wider. Great tire, BTW.

    Hopefully I'll get some negative rep for posting and liking my Niner carbon fork. Like I really care. Why was this system even started? If you can't tell in a couple of posts whether or not the other guy/gal knows what they're talking about, you deserve to be given bad advice.

  21. #421
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    Know I'm gonna get flamed for this but, after reading thru this thread, I noticed that the guys who claim to know the guy so well and how well he takes care of his gear, etc. all have posted only in this thread - three or four posts total. Just seems to me given the fact they all intimately know this exceptionally skilled rider who, "takes better care for his equip. than most of us do our children" they must all be ardent Mtn bikers but none have ever posted on MTBR until this thread appears!!!??

    Just sayin'!!
    If you don't like the way I ride, stay on the road!!!

  22. #422
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    AP,
    If you read this entire thread than you know that the OP was NOT the rider, and that this has gone to litigation, so few, if any are posting. Ride Fountainhead weekly, do not know the rider personally, yet, know of him through others. The guys posting, that you've brought into question - did so to deflect the abusive comments made, just like ^^^ and are not active on this forum, but club members that build/support area trails.

    Unfortunately, some MTBR users have a reputation for attacking the rider, and refusing to believe that it's even possible for there to be an issue with their brand of bike or part. It suucks to be interrogated, and much more so when seriously hurt.

    Today's practice of "blame the patient" makes the one harmed to prove their innocence beyond a shadow of doubt. This reduces many cases from going to trial, and enables doctors to both avoid defending their actions, and manage their skyrocketing insurance premiums. Ask one.

    Before you jump on the "it must be the riders fault" bandwagon, please consider how you'd feel while in the hospital, reading those d-bag comments that target you, or your hurt friend.

    Yes, shiite does happen while JRA, and we all accept risks every time we ride. To manage those risks, all we can do is to maintain our bikes, and control.

  23. #423
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    Quote Originally Posted by Flyin_W View Post
    AP,
    If you read this entire thread than you know that the OP was NOT the rider, and that this has gone to litigation, so few, if any are posting. Ride Fountainhead weekly, do not know the rider personally, yet, know of him through others. The guys posting, that you've brought into question - did so to deflect the abusive comments made, just like ^^^ and are not active on this forum, but club members that build/support area trails.

    Unfortunately, some MTBR users have a reputation for attacking the rider, and refusing to believe that it's even possible for there to be an issue with their brand of bike or part. It suucks to be interrogated, and much more so when seriously hurt.

    Today's practice of "blame the patient" makes the one harmed to prove their innocence beyond a shadow of doubt. This reduces many cases from going to trial, and enables doctors to both avoid defending their actions, and manage their skyrocketing insurance premiums. Ask one.

    Before you jump on the "it must be the riders fault" bandwagon, please consider how you'd feel while in the hospital, reading those d-bag comments that target you, or your hurt friend.

    Yes, shiite does happen while JRA, and we all accept risks every time we ride. To manage those risks, all we can do is to maintain our bikes, and control.
    Did he jump on a bandwagon?
    You're rushing to a bit of a conclusion there.
    At the same time, CoJ, who wasn't even there, started this thread with a couple of shocking pictures, almost exactly zero information, and a "what do you need to know?" attitude... exactly the kind of sympathy-seeking thread that blasts manufacturers undeservedly for no apparent reason. He went on to falsely accuse me of lying for posting a picture of a buddy of mine's steel fork that snapped. A lot of the BS precipitated from his repeated d00shy comments.
    AND... if you follow the timeline of the thread, you'll see that people who know the rider started *****ing about negative comments before any had even happened.
    This is not a "blame the patient" situation... it is one in which a d0uch3bag posted some shocking photos with almost no information and fanned the flames repeatedly. There are actually very very few negative posts directed toward the rider in the thread.
    That's why these threads are stupid and unecessary. Zero good was served, nobody will know how it ended or even what happened, and a bunch of BS and flaming went down uselessly in the interim.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
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  24. #424
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    How did my profession get dragged into this?

  25. #425
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    Quote Originally Posted by DrDon View Post
    How did my profession get dragged into this?
    Just face it, it's all your fault, perhaps counting out WW2 and maybe 1 of the latest tsunamis


    Magura / whom also shares a related profession.

  26. #426
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    blame the patient

    Quote Originally Posted by PoisonDartFrog View Post
    MTBR Guidelines to be used whenever someone posts a thread about a component failure:

    1. Assume it was installed incorrectly.
    2. Assume the rider is unskilled.
    3. Assume it was abused.
    4. Point out that other similar components fail too.
    5. Express doubt because you have one "and it has never happened to you".
    6. Ask for sh1tloads of pics or other evidence. If the OP fails to do this, assume that is evidence of dishonesty.
    7. Give the OP the 3rd degree in an attempt to discover "lies" or other inconsistencies in their story.
    8. Simply refuse to believe it.
    9. Rat-hole the thread with pointless technicalities in an attempt to prove god-knows-what.
    10. Shoot the messenger and ask why they want to bash the manufacturer.

    Oh wait, never mind.
    mf,
    Agree this thread is a complete cluster due to the OP not being the rider, editing his posts, and his replies.
    By AP's post 194, and questioning the validity/integrity of those that posted in the riders defense he was boarding.
    Check posts 78,124,125,137 most follow comments and are by older mtbr members.
    Got no dog in this fight, yet ride rigid, and Fh is close to home.

  27. #427
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    Quote Originally Posted by DrDon View Post
    How did my profession get dragged into this?
    Wait.....aren't you a Chiropractor? If so, you don't count!
    Just kidding: some of my best friends are DC's.

    As to the niner fork, I rode mine on a rocky trail at altitude today for the first time. I used a Spinergy Xyclone Disc wheel (plush) and a Maxxis Ardent 2.4 tire, inflated to 28 psi (also plush.) But that is a trail I just ROLL on my Joker, without even feeling hardly anything. Today, on a 853 steel frame, with those plush wheels and tires, the front end of that bike just beat me UP. It was fast, and light, but it HURT.

    Don't never let nobody tell you them Niner forks are flexy!

  28. #428
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    Quote Originally Posted by Flyin_W View Post
    mf,
    Agree this thread is a complete cluster due to the OP not being the rider, editing his posts, and his replies.
    By AP's post 194, and questioning the validity/integrity of those that posted in the riders defense he was boarding.
    Check posts 78,124,125,137 most follow comments and are by older mtbr members.
    Got no dog in this fight, yet ride rigid, and Fh is close to home.
    all good.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
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  29. #429
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    Quote Originally Posted by meltingfeather View Post
    Did he jump on a bandwagon?
    You're rushing to a bit of a conclusion there.
    What I was gonna say!!! I was just making an observation!!!
    If you don't like the way I ride, stay on the road!!!

  30. #430
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    Hate to break it to you but MTBR is not the center of the MTB universe. Post count, membership duration and rep are not directly related to saddle time or experience.

    Quote Originally Posted by Flyin_W View Post
    AP,
    If you read this entire thread than you know that the OP was NOT the rider, and that this has gone to litigation, so few, if any are posting. Ride Fountainhead weekly, do not know the rider personally, yet, know of him through others. The guys posting, that you've brought into question - did so to deflect the abusive comments made, just like ^^^ and are not active on this forum, but club members that build/support area trails.

    Unfortunately, some MTBR users have a reputation for attacking the rider, and refusing to believe that it's even possible for there to be an issue with their brand of bike or part. It suucks to be interrogated, and much more so when seriously hurt.

    Today's practice of "blame the patient" makes the one harmed to prove their innocence beyond a shadow of doubt. This reduces many cases from going to trial, and enables doctors to both avoid defending their actions, and manage their skyrocketing insurance premiums. Ask one.

    Before you jump on the "it must be the riders fault" bandwagon, please consider how you'd feel while in the hospital, reading those d-bag comments that target you, or your hurt friend.

    Yes, shiite does happen while JRA, and we all accept risks every time we ride. To manage those risks, all we can do is to maintain our bikes, and control.
    Zip ties? Not on my bike!

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  31. #431
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    Quote Originally Posted by jeff View Post
    Hate to break it to you but MTBR is not the center of the MTB universe. Post count, membership duration and rep are not directly related to saddle time or experience.
    Sooooooooo freaking true !!!

  32. #432
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    Hopefully the rider has made a full recovery and is riding strong again.

    Would'nt surprise me if the OP, CoJ is a party in the letigations. What were they thinking.

  33. #433
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    Quote Originally Posted by jeff View Post
    Hate to break it to you but MTBR is not the center of the MTB universe. Post count, membership duration and rep are not directly related to saddle time or experience.
    You may be right. Probably best to reply to AP, not I, who implied this concept.
    To me, your moniker (Stokeless Azzhat) clearly conveys both your viewpoint, and net value.

  34. #434
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    I dont have anything to add but that didnt keep anyone else from posting.

  35. #435
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    Quote Originally Posted by jeff View Post
    Hate to break it to you but MTBR is not the center of the MTB universe. Post count, membership duration and rep are not directly related to saddle time or experience.
    uh... that was part of his point.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
    29er Tire Weight Database

  36. #436
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    Please, can I install with carbon Niner fork one CrankBrithers Iodine 3 stem or Cobalt 3 stem ?

  37. #437
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    My installation instructions say no wedge clamp style stems, so the Iodine 3 isn't an option. The clamps on the Cobalt seem like they'd work fine.

    I'd suggest starting a new thread for other questions about the fork, rather than bringing this thread back to life.

  38. #438
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    How is it that a thread on a broken fork actually has gone 12 pages? Come on people, parts break. It's no big deal.
    A garage full of steel frames means happiness.

  39. #439
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    Quote Originally Posted by CS2 View Post
    How is it that a thread on a broken fork actually has gone 12 pages? Come on people, parts break. It's no big deal.
    Not when parts break and then you die.

  40. #440
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    I am afraid to mount up my Flyxii 541g rigid fork because of this thread.

    Not if, but when...

  41. #441
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    Quote Originally Posted by Adroit Rider View Post
    I am afraid to mount up my Flyxii 541g rigid fork because of this thread.

    Not if, but when...
    It is up to you. I did over a 1000 miles on my Trigon fork but on the road. I would not feel comfortable bombing downhill on a carbon fork with a carbon steerer.

    You should have tried Ritchey Pro carbon 29 fork with an aluminum steerer. I like it a lot better. Niner is stiff and flexes around brake area which I do not like.
    “You can always count on Americans to do the right thing - after they've tried everything else.”

  42. #442
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    I bought the NINER fork, saw this thread and got spooked out for two months. Finally installed it and maiden ride yesterday. It was soooooooooooo good!

  43. #443
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    It's interesting that when I started talking about a niner carbon fork, this thread was immediately pointed out to me. I sent the person who pointed me to this thread the following video, and they suddenly decided they may have to rethink their stance on carbon components.


    And I can't post the video because I don't have ten posts.

    Any who, it's a pink bike video shot at santa cruz. It's carbon vs aluminum. Look it up. Carbon is better than aluminum, but haters gonna hate.

  44. #444
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    Quote Originally Posted by Cotharyus View Post
    It's interesting that when I started talking about a niner carbon fork, this thread was immediately pointed out to me. I sent the person who pointed me to this thread the following video, and they suddenly decided they may have to rethink their stance on carbon components.


    And I can't post the video because I don't have ten posts.

    Any who, it's a pink bike video shot at santa cruz. It's carbon vs aluminum. Look it up. Carbon is better than aluminum, but haters gonna hate.


    <iframe width="560" height="315" src="http://www.youtube.com/embed/6APhKvaW6ig" frameborder="0" allowfullscreen></iframe>
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
    29er Tire Weight Database

  45. #445
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    Impressive!

    Quote Originally Posted by meltingfeather View Post


    <iframe width="560" height="315" src="http://www.youtube.com/embed/6APhKvaW6ig" frameborder="0" allowfullscreen></iframe>
    Did anybody else wince that they didn't wear safety glasses during all of this? I spend a lot of time in oil refineries, and there will be no shortage of people telling you to put your glasses on if you forget.

  46. #446
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    That test totally shows that carbon sucks dude. Right? Fersure.

    Actually I think that video should be required viewing for anyone to be able to post on MTBR.
    No it never stops hurting, but if you keep at it you can go faster.

  47. #447
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    Yeah, it did seem like to me they should have some eye protection, but then I'm the guy who wears glasses and puts on a full face shield anytime I do something that might result in small flying chips or bits of stuff when I'm working in the shop. Thanks for posting that for me meltingfeather.

  48. #448
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    would love to see the same test with a chinese frame that are being talked about lately.

  49. #449
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    Quote Originally Posted by modifier View Post
    That test totally shows that carbon sucks dude. Right? Fersure.

    Actually I think that video should be required viewing for anyone to be able to post on MTBR.
    I wished my $160 carbon brake levers were only as strong as the frames in the video... Luckily, epoxy can make carbon look like new for resale *tee-hee* . Here's hoping the $40 aluminum ones that I replaced them with will hold up


    *edit* I NEVER SOLD THE LEVERS!! My original writeup made it sound like I repaired the carbon levers and sold them. I was being sarcastic as I think being able to repair carbon to look like new is a downside for the used market. I never sold the levers and never would do that. Anyway, sorry for the confusion. I work odd hours and post on here when I am half asleep sometimes. I thought meant sarcasm, my bad.
    Last edited by FireLikeIYA; 06-26-2012 at 08:13 PM.
    Killing it with close inspection.

  50. #450
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    Quote Originally Posted by FireLikeIYA View Post
    I wished my $160 carbon brake levers were only as strong as the frames in the video... Luckily, epoxy can make carbon look like new for resale *tee-hee* . Here's hoping the $40 aluminum ones that I replaced them with will hold up.
    what are you referring to?

  51. #451
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    Quote Originally Posted by bt View Post
    what are you referring to?
    Sorry, I was replying to Modifier. His remark lacked a little perspective on individuals love/hate relationships with CF. He thinks people should see a propaganda video on why CF is superior so they can repeat to others on why it is so... or else they can't have an opinion. WTF?... anyway I got sucked in and replied to his remark.
    Killing it with close inspection.

  52. #452
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    I had a used carbon fiber GT STS in which there was a hairline crack on the alloy part of the
    head tube. So I try destroying the frame with an ax. Then with a sledgehammer.
    It was almost impossible to destroy.

    Finally after several blows with the sledgehammer, the top tube buckled and cracked. So I don't know about this story with the fork, it looks
    worse than when I bashed my CF frame with the sledgehammer.

    ps--when destroying a frame, make sure to put a vise on the floor and have it
    grip the BB area for a solid upright position. Wear goggles or sunglasses and don't hit your foot.

  53. #453
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    Quote Originally Posted by FireLikeIYA View Post
    Sorry, I was replying to Modifier. His remark lacked a little perspective on individuals love/hate relationships with CF. He thinks people should see a propaganda video on why CF is superior so they can repeat to others on why it is so... or else they can't have an opinion. WTF?... anyway I got sucked in and replied to his remark.
    I didn't get to see what you wrote but it seems that it was not supportive.

    Opinion is whether or not you like broccoli. No one can tell you that you are wrong and that broccoli tastes good if you don't like it personally.

    When executed properly carbon based composite materials offer an advantage over traditional metals that goes beyond opinion.

    The majority of the flagship frames from the big companies and the bikes most top athletes race (on and off road) are carbon composite these days.

    Propaganda implies that the information given is not based on truth and is only provided to mislead someone. How is the testing shown in the video falsely representing the strength of carbon vs aluminum?

    The only drawback at this point is cost and limited accessibility to the technology for the small builder. Cost will come down in time with market saturation. Small guys with have to be content with metal for a while.

    The reason I said people should watch the video is it pretty clearly dispels any possible argument that carbon fiber isn't strong, as is voiced repeatedly in forums. If people still think there is room for debate I give up and won't beat the dead horse any more.
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  54. #454
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    Quote Originally Posted by modifier View Post
    I didn't get to see what you wrote but it seems that it was not supportive.

    Opinion is whether or not you like broccoli. No one can tell you that you are wrong and that broccoli tastes good if you don't like it personally.

    When executed properly carbon based composite materials offer an advantage over traditional metals that goes beyond opinion.

    The majority of the flagship frames from the big companies and the bikes most top athletes race (on and off road) are carbon composite these days.

    Propaganda implies that the information given is not based on truth and is only provided to mislead someone. How is the testing shown in the video falsely representing the strength of carbon vs aluminum?

    The only drawback at this point is cost and limited accessibility to the technology for the small builder. Cost will come down in time with market saturation. Small guys with have to be content with metal for a while.

    The reason I said people should watch the video is it pretty clearly dispels any possible argument that carbon fiber isn't strong, as is voiced repeatedly in forums. If people still think there is room for debate I give up and won't beat the dead horse any more.
    You have several good points and I am not in total disagreement with you. I agree that the video is very convincing and does prove certain aspects of CF are superior to Al but I don't believe that it is a tell all. I just believe that cheaper materials might fit certain applications better than carbon and provide longer life. CF for the main triangle of a short link FS bike, sure... CF would be superior (although, for me, it doesn't make sense for the rear triangle). CF for a seatpost, handlbar or forks.... maybe not the best application. I am not a hater of CF as I think it is great but I also know that "stronger" isn't a material property. Besides the "extra care" that must be given to CF parts I also question the QC in the production of the parts. With metal in the assembly process it is easier to determine when an issue arises. Maybe the heat on the weld wasn't high enough... well, you can determine what frames where effected by it. In my opinion, regarding CF, a defect in a frame is more likely to be completely independent of all the other frames in the same batch. You wont know until it fails and then how do you prove it wasn't user error? Just look at different manufacturer warranties on CF parts compared to their Al counterparts and I think you will get my drift. If CF is really superior then why are the warranties 1/3 the length of the same manufacturers Al version? Just my $.02.
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  55. #455
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    I've been using carbon fiber forks, frames, seatposts, stems, bars, cranksets and brake levers since they were available for bikes and I have never had any issues or "extra care" associated with them. I have a 2005 FS bike that is almost all carbon except the wheels and shock and it is still holding up just fine including the rear triangle and that is old technology by now. Carbon rims are now all the rage if you can afford them.

    I've never heard of warranties being shorter for carbon stuff than for aluminum from the same manufacturer, but I'll take your word for it. I can't explain that if it is true and it's probably not a good idea on their part if they are trying to instill confidence in a new(ish) material.

    Let's check in again in 20 years and see where it's at. I bet you won't see much metal by that point left on bikes except in low end.
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  56. #456
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    Quote Originally Posted by modifier View Post
    How is the testing shown in the video falsely representing the strength of carbon vs aluminum?
    Man I've typed out two very thorough responses so far, and they've been obliterated by some auto page refresh thing. Suck.

    In a nutshell, the video compares the resistance of two frame designs to forces in certain directions.

    To better demonstrate the strength of carbon vs aluminum, you'd need to apply the same force to two samples of the materials of the same dimensions. Though the frames looked similar, they were probably not of the same dimensions, thus the video was probably misleading.

    Stress = (force)/(unit area). All we saw was a measure of the force.

    To strictly answer the question of "what material is stronger", we'd first have to choose what kind of strength we care about (ultimate tensile, yield, endurance limit, hardness, etc), then take two material samples of equal dimensions and apply force to them in a way that is meaningful.

    For instance, if we care about ultimate tensile strength we'd select a tube of carbon fiber and a tube of aluminum of equal dimensions, mount them in a test machine in the same manner, and pull them apart, noting the force required to do so. Knowing the area of both samples, we'd be able to say that the ultimate yield strength of X is greater than that of Y.

    The video clearly shows that one carbon fiber frame is stronger in those tests than another aluminum frame, but it does not show that carbon fiber is "stronger" than aluminum.

    I think all materials used for bikes are cool, but stress-strain curves are indisputable. Steel tends to have predictable elastic and plastic deformation properties. When stressed past its yield point and starts to deform, steel actually gets harder for a little while (this is called "strain hardening") then proceeds to break later on down the stress-strain curve.

    Composites, as we have seen, don't respond to stress in this same way, they just tend to fail suddenly when stressed past a certain limit. They don't really have well defined yield points.

  57. #457
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    Quote Originally Posted by HOV View Post
    Man I've typed out two very thorough responses so far, and they've been obliterated by some auto page refresh thing. Suck.

    In a nutshell, the video compares the resistance of two frame designs to forces in certain directions.

    To better demonstrate the strength of carbon vs aluminum, you'd need to apply the same force to two samples of the materials of the same dimensions. Though the frames looked similar, they were probably not of the same dimensions, thus the video was probably misleading.

    Stress = (force)/(unit area). All we saw was a measure of the force.

    To strictly answer the question of "what material is stronger", we'd first have to choose what kind of strength we care about (ultimate tensile, yield, endurance limit, hardness, etc), then take two material samples of equal dimensions and apply force to them in a way that is meaningful.

    For instance, if we care about ultimate tensile strength we'd select a tube of carbon fiber and a tube of aluminum of equal dimensions, mount them in a test machine in the same manner, and pull them apart, noting the force required to do so. Knowing the area of both samples, we'd be able to say that the ultimate yield strength of X is greater than that of Y.

    The video clearly shows that one carbon fiber frame is stronger in those tests than another aluminum frame, but it does not show that carbon fiber is "stronger" than aluminum.

    I think all materials used for bikes are cool, but stress-strain curves are indisputable. Steel tends to have predictable elastic and plastic deformation properties. When stressed past its yield point and starts to deform, steel actually gets harder for a little while (this is called "strain hardening") then proceeds to break later on down the stress-strain curve.

    Composites, as we have seen, don't respond to stress in this same way, they just tend to fail suddenly when stressed past a certain limit. They don't really have well defined yield points.
    the test wasn't meant to be a scientifically bulletproof demonstration of relative material properties.
    if you put two tubes of equal dimension in a test rig and break them, the obvious and very relevant question is, "what the hell does that have to do with my bike frame?"
    while your comments aren't completely lacking in fact, i think they are a little eggheady and out of touch with the context. for instance, since geometry and layup design plays an enormous role in the structural performance of carbon fiber elements, would the results of a test you suggest be anything other than completely useless from a mountain biking perspective?
    this from a licensed professional engineer who TA'd materials lab in grad school.
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    I know I said I would shut up but it's hard when you guys fire back with this stuff.

    So I guess the naysayers of carbon will say that the only reason that the big guys who can afford the tooling and r&d to build carbon frames are doing so on all their top of the line bikes only as a marketing ploy? People like that reasoning around here when cutting down new ideas. Might as well plug it in here too. Ha.

    GT built the first commercial carbon DH frame a few years ago and reported that it was 10 times the strength for the same weight in aluminum alloy. They haven't abandoned it due to failures btw. Last year Trek came out with that sweet and light carbon DH frame. Now the 2013 Specialized top line DH bike comes in carbon. Not to mention their flagship S Works 29er XC bike. Etc across the industry.

    Go to a cat 1 road race and report back on how many metal frames you see. Or do the same at a F1 race. Or a military fighter plane. You all are saying that if they could they would all be using steel. Or titanium or aluminum, but they don't because they are fooling themselves and haven't done the "right testing". Lol. Give up!

    I'm sorry but there is nothing you tell me that is going to convince me that carbon or similar composite materials for most components on a bicycle can't be superior in all ways. Weight, strength, stiffness, shock absorption and longevity. If implemented correctly and built right. Parts of the drive train and suspension excluded, for the moment. It just ain't cheap and easy. That's all.

    Enjoy your metal.
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    I completely agree with your assessment of my comments being eggheady, but they're spot on in addressing the question "How is the testing shown in the video falsely representing the strength of carbon vs aluminum?"

    My answer: the video doesn't represent a comparison of the strength of carbon fiber vs aluminum, it represents the performance of two particular bicycle frame designs in a destructive testing environment. The two should not be confused.

  60. #460
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    Quote Originally Posted by modifier View Post
    You all are saying that if they could they would all be using steel. Or titanium or aluminum, but they don't because they are fooling themselves and haven't done the "right testing". Lol. Give up!
    No, no one said that.


    Quote Originally Posted by modifier View Post
    I'm sorry but there is nothing you tell me that is going to convince me that carbon or similar composite materials for most components on a bicycle can't be superior in all ways. Weight, strength, stiffness, shock absorption and longevity. If implemented correctly and built right. Parts of the drive train and suspension excluded, for the moment.
    Sure.

    I've had carbon frames, carbon forks, and I currently use carbon handlebars. I think it's a great material with great potential for a lot of different applications. Heck, we're carbon-based life forms.

  61. #461
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    Originally Posted by modifier View Post
    >>You all are saying that if they could they would all be using steel. Or titanium or aluminum, but they don't because they are fooling themselves and haven't done the "right testing". Lol. Give up!<<

    Quote Originally Posted by HOV View Post
    No, no one said that.
    No one said that directly, however by saying that carbon composites aren't really as good as good old metal, which is generally speaking what everyone who puts down composites is saying, they are also saying that all the big guys from F1 to a Lockheed Martin are wrong, or that a bicycle is so much more advanced than a anything else that it requires it's own world of material physics.

    I'm speaking purely from a best tool for the job point of view, not about aesthetics or getting back to basics or the springy ride of a Ti frame. I'm also not saying that everyone who builds with metal should give it up. There are lots of reasons to build with metal. Primarily that it allows the little guy with a shop and a few tools to build frames.

    I'm simply stating that when you get down to trying to build a better machine, like all the industries I spoke of are, then composite can't really be beat. Until they come up with something better.
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  62. #462
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    Quote Originally Posted by modifier View Post
    Originally Posted by modifier View Post
    >>You all are saying that if they could they would all be using steel. Or titanium or aluminum, but they don't because they are fooling themselves and haven't done the "right testing". Lol. Give up!<<



    No one said that directly, however by saying that carbon composites aren't really as good as good old metal, which is generally speaking what everyone who puts down composites is saying, they are also saying that all the big guys from F1 to a Lockheed Martin are wrong, or that a bicycle is so much more advanced than a anything else that it requires it's own world of material physics.

    I'm speaking purely from a best tool for the job point of view, not about aesthetics or getting back to basics or the springy ride of a Ti frame. I'm also not saying that everyone who builds with metal should give it up. There are lots of reasons to build with metal. Primarily that it allows the little guy with a shop and a few tools to build frames.

    I'm simply stating that when you get down to trying to build a better machine, like all the industries I spoke of are, then composite can't really be beat. Until they come up with something better.
    I really love that you do my usual work now. Much appreciated.

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    Quote Originally Posted by HOV View Post
    I completely agree with your assessment of my comments being eggheady, but they're spot on in addressing the question "How is the testing shown in the video falsely representing the strength of carbon vs aluminum?"
    two frames of the same model tested destructively in the same way is relevant to readers of a bike forum.
    normalized performance of test specimens is of no relevance and, more importantly, no interest to 99.5% of readers here.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
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  64. #464
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    A local guy who is big just broke his aluminum Niner frame after just a few months of riding. That frame has a 2 year warranty and they are replacing it. Btw it failed catastrophically with no warning and it's a good thing he was going up hill when it happened. See pic. Another friends Aluminum rear triangle failed the same way on his Specialized. All of a sudden in 2 pieces.

    Unlike their 2 (TWO) year Aluminum warranty their carbon frames, bars and forks have a 5 (FIVE) year warranty. How can that be?

    >>Niner Bikes offers a five year warranty on all carbon products. This includes the Niner Air 9 Carbon frame, the Niner Carbon Fork and the Niner Flat Top carbon bar.

    We are proud of the testing and care we put into the design and manufacture of our carbon products. We feel that the best way to show this is to offer a 5 year warranty period on all carbon items - our C5 program. This warranty is retroactive for all owners of Niner carbon products.<<
    Attached Thumbnails Attached Thumbnails Catastrophic failure Niner Carbon Fork-rip-broke.jpg  

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    Carbon fiber is always going to be way weaker than aluminum or steel...I would NEVER trust a CF fork on a rigid bike where stress levels are amplified...if you are worried about weight go CF if you dont want your face to get rearranged on your stem stick with metal simple.......I always go for strength cause if some parts fail you could end up in a coma...so i'll pedal a few more pounds around and bunny hop the rock garden @ 30MPH thank you

  66. #466
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    Quote Originally Posted by skibikeguy1 View Post
    Carbon fiber is always going to be way weaker than aluminum or steel...I would NEVER trust a CF fork on a rigid bike where stress levels are amplified...if you are worried about weight go CF if you dont want your face to get rearranged on your stem stick with metal simple.......I always go for strength cause if some parts fail you could end up in a coma...so i'll pedal a few more pounds around and bunny hop the rock garden @ 30MPH thank you
    That was deep.

  67. #467
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    Well everyone knows what opinions are like. I think it's safe to say the bottom line is if you're afraid of getting hurt, stay home. This thread really is that much more interesting to me since I broke my (aluminum) frame this past friday morning. Fortunately, a local fabricator has indicated they can fix the frame with ease, and it won't affect strength in any way. There's an advantage for metal vs. carbon. But I have to wonder: If I had a carbon frame, would it have broken?

    We'll never know the answer to that question, but I do think that the video is relevant to the users on this forum. I also think that people are right when they say it doesn't address "absolute strengths " of materials.

    Fact: F1 cars (since they were brought up) are constructed largely (chasis and suspension) of carbon fiber.

    Fact: The suspension parts on an F1 car are probably the MOST RELEVANT parts of an F1 car for a cyclist to look at in this debate.

    Fact: F1 suspension arms are VERY strong in the directions/plains they are designed to take force on, but they shatter very easily if you apply force in other directions. This is by design, to keep them as light as possible.

    What's that means to a cyclist? It means you better trust the engineering department if you want a carbon frame. If you choose to trust them, I think it's clear you can have a stronger, lighter bike frame made from carbon than you ever could from metal. But again, nothing is without risk.

  68. #468
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    Quote Originally Posted by modifier View Post
    by saying that carbon composites aren't really as good as good old metal
    Nope, never said that either. In fact I said that I liked CF, that I used and continue to use CF bikes & components, and that the material definitely has a place in a wide variety of applications.

    Quote Originally Posted by meltingfeather View Post
    two frames of the same model tested destructively in the same way is relevant to readers of a bike forum.
    normalized performance of test specimens is of no relevance and, more importantly, no interest to 99.5% of readers here.
    I've already agreed with that statement.

    Once again, my comments were only in response to modifier's single question: "How is the testing shown in the video falsely representing the strength of carbon vs aluminum?"

    Applying a little critical thinking to that question, the answer is: "the video doesn't show anything about the relative strength of the two MATERIALS. It shows the relative resistance of two FRAME DESIGNS to forces applied in a particular way."

    There's simply no disputing this statement.

    If I were trying to choose between those two frames, that video would be just the ticket. However, it does nothing to illustrate the difference between CF and Al between any other two designs. At best, it shows that CF CAN be tougher than aluminum. Ok, anyone who has wrapped up their old sandwich in Al foil should be able to intuit that.

    But - if the desire is to talk pure strength of materials - which many people automatically translate that video into - then we need to refer to empirically established data as the basis for our conversation. I'm not going to go into what stress-strain diagrams look like for steel vs composites, but (meltingfeather), I know you know. The problem is that most people don't. Doesn't seem like modifier knows his way around one very well.

    modifier - no bash intended. It's just that there's really no substitute for formal engineering training and your argument has thus far been based on anecdote. I don't even disagree with you but I do disagree with how you're building your argument. I thought I was well-educated until I started my formal engineering training. I had already completed a graduate degree so I must have been smart, right? Turns out I had about the level of scientific knowledge they had in ancient Greece, except I was worse than the ancient Greeks at math.

    Words are important, and if we're having a technical conversation, then so are principles of science & engineering. That video was cool but based on that alone, people shouldn't go around saying that it's required viewing and CF is the alpha and the omega for bicycling, it rules over all, yay, let's go make engine blocks, drill bits, and tires out of CF too. No. CF is a material like any other, and there's always a trade space in how it is considered in design.

  69. #469
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    Quote Originally Posted by Cotharyus View Post
    This thread really is that much more interesting to me since I broke my (aluminum) frame this past friday morning. Fortunately, a local fabricator has indicated they can fix the frame with ease, and it won't affect strength in any way. There's an advantage for metal vs. carbon. But I have to wonder: If I had a carbon frame, would it have broken?
    That depends on what kind of aluminum it is. If it's 7000 series aluminum you may be fine. If it's 6000 series aluminum the heat from welding will cause the area right next to the weld to loose elasticity and over flex cycles break again. If you weld 6000 you need to go through a whole frame or whole part 2 step heat treating process to get back to a T6 rating.

    Who knows if it would have broken if carbon. With hydroforming these days they are able to make frame shapes to help alleviate high stress areas in aluminum easier than in the past but it's still much easier to manipulate shape and wall thickness as well as fiber orientation with carbon fiber and optimize for what you need.
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  70. #470
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    Quote Originally Posted by Cotharyus View Post
    Fortunately, a local fabricator has indicated they can fix the frame with ease, and it won't affect strength in any way.
    You'd better trust your fabricator if you want an aluminum repair... tricky territory.
    Quote Originally Posted by Cotharyus View Post
    There's an advantage for metal vs. carbon.
    Carbon can be repaired.
    Take a look as some of Calfee's work (here).
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
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  71. #471
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    HOV, I'm not a trained engineer or a trained architect or bla bla bla... I could go on with a long list of things I participate in along side the guys with degrees. I just solve problems and build things and make them better. I guess I'm better in the field than at the lectern. Sometimes it's nice to not be hampered by data and formulas.

    However, if I was going to build a new suspension fork, which is on my mind, I would have to contract the services of someone more specialized to make it happen. Same thing is I was going to build a carbon fiber frame. I'll cross that hurdle when it comes up.

    Sometimes anecdotal evidence and observations can get you farther than theorems to real world progress.
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    Quote Originally Posted by HOV View Post
    Once again, my comments were only in response to modifier's single question: "How is the testing shown in the video falsely representing the strength of carbon vs aluminum?"

    Applying a little critical thinking to that question, the answer is: "the video doesn't show anything about the relative strength of the two MATERIALS. It shows the relative resistance of two FRAME DESIGNS to forces applied in a particular way."

    There's simply no disputing this statement.
    The hair splitting and narrow interpretation of a single comment is... strange.

    Quote Originally Posted by HOV View Post
    But - if the desire is to talk pure strength of materials - which many people automatically translate that video into - then we need to refer to empirically established data as the basis for our conversation. I'm not going to go into what stress-strain diagrams look like for steel vs composites, but (meltingfeather), I know you know. The problem is that most people don't. Doesn't seem like modifier knows his way around one very well.
    How is it that you want to evoke "critical thinking" yet repeatedly choose to ignore the primacy of finished element geometry and layup for evaluating carbon strength?
    Quote Originally Posted by pvd
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    Quote Originally Posted by modifier View Post
    HOV, I'm not a trained engineer or a trained architect or bla bla bla... I could go on with a long list of things I participate in along side the guys with degrees. I just solve problems and build things and make them better. I guess I'm better in the field than at the lectern. Sometimes it's nice to not be hampered by data and formulas.

    However, if I was going to build a new suspension fork, which is on my mind, I would have to contract the services of someone more specialized to make it happen. Same thing is I was going to build a carbon fiber frame. I'll cross that hurdle when it comes up.

    Sometimes anecdotal evidence and observations can get you farther than theorems to real world progress.
    I agree amigo, paralysis by analysis is alive and well.

    Sometimes it's better just to bend metal and see where that gets you. Too bad CF don't bend so good, son! J/K

  74. #474
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    Quote Originally Posted by meltingfeather View Post

    Carbon can be repaired.
    Take a look as some of Calfee's work (here).
    Yes, I was going to mention that, and notice they offer a 10 year guarantee on their work. You aren't going to find that on an aluminum repair.
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  75. #475
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    Carbon is easily repairable..

    Ahh...the days of old where folks envisioned themselves in their own garages with an arc welder doing repairs to their own steel frames..

    How many guys actually ended up doing this back in the day?? Answer: Hardly anyone.

    There was a recent article in a bike mag stating that carbon fiber is the most easily repaired bike material today with the best outcome for longevity after repairs.

    There just are not very many guys trained in this area YET. It is becoming more common though and Calfee is seeing some competition in my area at least...

  76. #476
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    Quote Originally Posted by meltingfeather View Post
    The hair splitting and narrow interpretation of a single comment is... strange.
    Ok. If you think being specific and answering questions as they are worded is strange, then *high five*.

    Quote Originally Posted by meltingfeather
    How is it that you want to evoke "critical thinking" yet repeatedly choose to ignore the primacy of finished element geometry and layup for evaluating carbon strength?
    I'm glad we agree, that's exactly my point. For evaluating strength of a finished design, geometry, material, material thickness are most certainly factors. As are a lot of other things done throughout the manufacturing process to ensure the design is executed right.

    Which means that the video in question clearly shows the performance of one design vs the other and very little about the materials in question.

    Here are things we agree upon. In your words:

    1. finished element geometry and layup is of primary importance in evaluating carbon strength
    2. two frames of the same model tested destructively in the same way is relevant to readers of a bike forum.
    3. normalized performance of test specimens is of no relevance and, more importantly, no interest to 99.5% of readers here.

    My only extension to your points #2 & 3 is that many people seeing that video will go automatically assume that the material alone is what causes the superior resistance to damage. I'm just trying to emphasize, as you say, the primacy of finished element geometry and layup for evaluating carbon strength.

    What's interesting here is that I'm in complete agreement with you, yet you're saying I'm wrong. Which means your'e saying you're wrong. I disagree, you're right!

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    [QUOTE=HOV;9450493

    Which means that the video in question clearly shows the performance of one design vs the other and very little about the materials in question.

    [/QUOTE]

    I disagree. Both frames are built to the best of their ability considering the limitations or advantages of each material and the CF frame ends up being stronger by a considerable amount. I wouldn't be surprised if your arms would break before you broke the frame.

    Plus with the ability to easily strengthen certain areas when necessary I'm thinking with some real world testing they can build a CF frame that will last longer and ride better too.

    UV damage is about the only thing to watch out for but I assume that by this point in development they have UV resistant adhesives and coating materials to make that issue no longer much of a concern. Or paint it.

    The idea of taking a straight 1.5" tube of the same wall thickness of CF and of AL and stressing both to failure really does not apply to much outside of the laboratory because that isn't a limitation you will have when building a bike frame or an airplane wing.

    I understand your argument, I just see it as academic.
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  78. #478
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    Quote Originally Posted by modifier
    Both frames are built to the best of their ability considering the limitations or advantages of each material and the CF frame ends up being stronger by a considerable amount. I wouldn't be surprised if your arms would break before you broke the frame.
    We agree here - the video clearly shows one frame being stronger than the other. I've never said anything different.

    Quote Originally Posted by modifier
    The idea of taking a straight 1.5" tube of the same wall thickness of CF and of AL and stressing both to failure really does not apply to much outside of the laboratory because that isn't a limitation you will have when building a bike frame or an airplane wing.

    I understand your argument, I just see it as academic.
    Material properties drive weight, cost, form factor/geometry, part interface considerations, manufacturing processes, manufacturing timelines, et cetera, ad nauseum. It's a very real limitation that critically defines the engineering trade space. Engineers building bike frames and airplane wings cannot disregard material properties as it is fundamental to their designs.

    Discussion of material properties are only "academic" here on mtbr, where the conversation is geared around the user end and the choices consumers can make about the products they buy. Thus, discussing the strength of the material outside of the context of the design is "academic" here.

    But saying they're not relevant outside the lab is simply incorrect.

  79. #479
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    If we keep this up much longer I'm sure we are going to piss of some people who hate debates like this and think we should just ride But of course they have the free will to not click on the update.

    Everyone knows that carbon fiber is stronger per unit weight than metals so that is a given and I don't think we are discussing that. And like I have said cost is the biggest limiting factor of CF construction making metal more affordable. The gain can be seen after the mold is produced and the layup is figured out with repetitive production over building a frame in a jig by welding sections together. Plus you can charge more for a better product. But we aren't really discussing profitability either.

    If you take the 2 tubes I spoke of and make everything the same except wall thickness and also make them the same weight I contend that the optimized CF tube will out perform the metal tube as it did in the frame test video making the video relevant in any context . Which is why people choose CFC when they want the best material for the job and cost is not the over riding concern.

    You appear to be arguing against this idea. If you aren't then wth are you arguing about? Semantics? Sentence structure?
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  80. #480
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    I'm definitely not buying a carbon fiber frame for at least 5 years. I'm seeing stories like this constantly where a part of the frame or a carbon fiber component just shears apart.

  81. #481
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    Quote Originally Posted by modifier View Post
    Everyone knows that carbon fiber is stronger per unit weight than metals so that is a given and I don't think we are discussing that.
    To be honest, I didn't know any properties of carbon fiber because I've never done any analysis with it. So I looked some up. What follows are some categories of strength, and some numbers representative of a particular type of metal or composite. Results vary widely between different grades of material.

    Ultimate Tensile Strength: the maximum stress a material experiences while being pulled apart.

    ASTM-A913 Grade 65 structural steel: 80,000 lb/sq in
    Alloy 6061-T6 aluminum: 38,000 lb/sq in
    Carbon fiber: 500,000 lb/sq in

    Yield strength: the stress at which the material is strained beyond the elastic limit and begins to permanently deform:

    ASTM-A913 Grade 65 structural steel: 65,000 lb/sq in
    Alloy 6061-T6 aluminum: 35,000 lb/sq in
    Carbon fiber: undefined: once the ultimate strength is exceeded, the material suddenly and catastrophically fails.

    Endurance limit: the stress under which the material can be cycled indefinitely without causing failure. Typically steel is (0.5 * ultimate tensile strength), aluminum is (0.4*ultimate tensile strength), so:

    ASTM-A913 Grade 65 structural steel: 40,000 lb/sq in
    Alloy 6061-T6 aluminum: 15,200 lb/sq in
    Carbon fiber: ? I cannot find any representative number, which is a bummer because this is quite relevant to this conversation.

    BTW, here's a great link on the subject specifically in regards to bicycles: Bob Brown Cycles: analysis

    So you're right that some CF is stronger than some metals. I'm very much interested in the endurance limit for CF.

    Also, during my little bit of poking around on the subject I found a nice chart describing the mechanical properties of CF with the fibers at different angles to the loading axis:

    Mechanical Properties of Carbon Fibre Composite Materials

    If I'm reading that chart correctly, the properties of the stuff change dramatically when loaded in such a way that is not designed for. That should be no surprise. Anyway, I had no beef with CF before and this little bit of poking around has really made me impressed with the stuff.

    Quote Originally Posted by modifier View Post
    If you take the 2 tubes I spoke of and make everything the same except wall thickness and also make them the same weight I contend that the optimized CF tube will out perform the metal tube as it did in the frame test video making the video relevant in any context...[clip]... You appear to be arguing against this idea. If you aren't then wth are you arguing about? Semantics? Sentence structure
    You may be right, but as it is now the only thing I have been arguing is that the video shows the comparative strength of two different designs, not two different materials. Given the information provided in the video, what I said is still true.

    The data I provided as an example above is, to me, the real supporting evidence of the statement that the material CF can be stronger than certain metals (given certain ways of measuring strength). That's it man, that's I was talking about. Pretty easy eh?

    Thanks for the conversation, I enjoyed learning more about CF. I'd really love to learn how to work with the stuff. You're right, there are a ton of possibilities.

  82. #482
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    Quote Originally Posted by HOV View Post
    Ok. If you think being specific and answering questions as they are worded is strange, then *high five*.
    I think you took a comment that wasn't nearly as specific as your analysis of it, which required assumption on your part, which means the intent of the comment is not what you were addressing, but your assumptions about specificity that was not there. That was my point.

    Quote Originally Posted by HOV View Post
    What's interesting here is that I'm in complete agreement with you, yet you're saying I'm wrong. Which means your'e saying you're wrong. I disagree, you're right!
    I never said you were wrong.
    I provided a little context-relevant perspective.
    If you agree with me, then you are right!

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    Time to stop believing the hype and start doing some science.
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  83. #483
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    Howzabout those Giants, eh?



    I love that you can repair carbon frames. It would not make a difference in this case of the carbon fork. I don't think there is a reasonable way to repair that kind of failure.

    Now sure how repairability is relevant to this topic.

  84. #484
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    Quote Originally Posted by 50mm View Post
    I'm definitely not buying a carbon fiber frame for at least 5 years. I'm seeing stories like this constantly where a part of the frame or a carbon fiber component just shears apart.
    I wouldnt worry about it, theres squillions of CF parts out there and you'll only ever hear the sob stories.

    I dont own a CF frame but i do own wheels/bars/posts/seats/levers ect and never had a failure.
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  85. #485
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    Quote Originally Posted by 50mm View Post
    I'm seeing stories like this constantly where a part of the frame or a carbon fiber component just shears apart.
    Are you sure you aren't confusing people often "saying" carbon fiber parts fail catastrophically more often than metal parts or actually "seeing" broken parts and frames?

    Everything can break if pushed beyond it's design parameters or if involved in a collision with an immovable object, which is where most CF failures occur I think. I'm sure it happens but I really don't see much stress failure at all except the occasional sensational story like this one. And metal frames break all the time, particularly aluminum. I've broken 3 so far.

    Personally I've been using carbon fiber since it came out in the late 80s and the only thing that ever failed for me was a first generation road bike seat post on a rigid mountain bike, and that only failed after I let someone else ride it who didn't know how to ride and even then it didn't just shear off. It cracked and bent but held together well enough for me to limp home on it.

    I think the fear of CF is akin to the fear of witches. Not much touch with reality but a lot of faith in wives tails.
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  86. #486
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    I have been reading this thread with some interest and would like to comment.

    There have been some comparisons made to composites being used in aviation and if good enough for that application it must be good enough for mountain biking. I don't believe that comparison holds water. As an airline pilot I have seen more than one composite radar nose cone destroyed by flight into hail or bird strike.

    While I acknowledge that the tensile strength of a carbon composite frame is adequately strong as demonstrated in the posted video, it does not address a concern I have with carbon. Understand that I would like to own a carbon frame if my concern was allayed.

    I have happily used carbon handlebars for over ten years but they are not subject to frequent impact. A mountain bike frame unlike a road bike is.

    I live in Norther New Jersey which is very rocky. There is hardly a ride on which I don't have a fist size rock flying of the front wheel and impacting the down tube with a resounding clang. With aluminum frames I've owned, I've needed not much more than touch up paint. I'd like to know what this type of pounding does to a composite frame over time. I've read (but can not confirm) that there can be internal/invisible damage to carbon fibers with the potential for failure.

    I'd appreciate realistic input.
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  87. #487
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    While impacts do happen they aren't common plus DH CF frames usually have guards at key areas like on the bottom of the down tube and on top of the chain stay. Also look up that video of Chris beating a 9er carbon fork and a steel fork with a hammer. The stuff is harder than you are led to believe. I've crashed many times on my almost all carbon bike and you could not tell. Plus with carbon bars end plugs are important. You have to be smart about it.

    They use CF in airplanes in a lot of other places than nose cones. But maybe that isn't the best application for it.

    I think I should get some kind of compensation from the USCF association or something. lol

    At this point in history I'm pretty sure negative opinions are going to keep trickling in no matter what I say or what kind of data is presented. Just mark my words and wait...it will be the norm at some point. Trust me.
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  88. #488
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    I impacted my Tallboy a few times at speed on rocks.
    It did not even make a mark.

  89. #489
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    Quote Originally Posted by TR View Post
    I impacted my Tallboy a few times at speed on rocks.
    It did not even make a mark.
    That is just the point. I have read that the impact and distortion/indentation can result in invisible damage or possible delamination internally, weakening the structure. It is not like pounding a solid composite structure like a fork with a hammer and chipping the paint. Pounding a carbon composite tube could be causing fibers to break. When I slam my aluminum frame into a rock and it's dented and possibly compromised, it is pretty obvious. As you have stated there is no (obvious) damage to your frame. Perhaps that is why there are reports of sudden catastrophic failure. I'm not stating this is the case. I don't know but I'd like some evidence to the contrary.
    The trouble with having an open mind is that people will insist on trying to put things in it.

  90. #490
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    Quote Originally Posted by Ronnie View Post
    That is just the point. I have read that the impact and distortion/indentation can result in invisible damage or possible delamination internally, weakening the structure. It is not like pounding a solid composite structure like a fork with a hammer and chipping the paint. Pounding a carbon composite tube could be causing fibers to break. When I slam my aluminum frame into a rock and it's dented and possibly compromised, it is pretty obvious. As you have stated there is no (obvious) damage to your frame. Perhaps that is why there are reports of sudden catastrophic failure. I'm not stating this is the case. I don't know but I'd like some evidence to the contrary.
    I have read that ti is a lifetime frame choice (and I own 2 ti bikes, soon to be 3); but I have seen no evidence that this is actually the case. In fact I have seen a few broken ti frames and forks on this very forum.
    I have also read that many small frame builders offer a lifetime warranty but that is yet to be proven and will obviously not be the case if the builder goes out of business or dies.

    I agree that if the impact is significant then I would not ride the CF frame again. But what is significant? I will pick my frame up and happily ride it again after it has bounced off a rock but I wrote of my CF road bike after it (and I) was hit by a car (despite there being no visible damage).

  91. #491
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    Quote Originally Posted by Ronnie View Post
    I have been reading this thread with some interest and would like to comment.

    There have been some comparisons made to composites being used in aviation and if good enough for that application it must be good enough for mountain biking. I don't believe that comparison holds water. As an airline pilot I have seen more than one composite radar nose cone destroyed by flight into hail or bird strike.

    While I acknowledge that the tensile strength of a carbon composite frame is adequately strong as demonstrated in the posted video, it does not address a concern I have with carbon. Understand that I would like to own a carbon frame if my concern was allayed.

    I have happily used carbon handlebars for over ten years but they are not subject to frequent impact. A mountain bike frame unlike a road bike is.

    I live in Norther New Jersey which is very rocky. There is hardly a ride on which I don't have a fist size rock flying of the front wheel and impacting the down tube with a resounding clang. With aluminum frames I've owned, I've needed not much more than touch up paint. I'd like to know what this type of pounding does to a composite frame over time. I've read (but can not confirm) that there can be internal/invisible damage to carbon fibers with the potential for failure.

    I'd appreciate realistic input.
    They basically build in extra carbon layers to protect against exactly that. What... you think this has never happened before?

  92. #492
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    We'll close this thread. It has gone wayyyy past the original Niner discussion.

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