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  1. #51
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    Quote Originally Posted by ThePunisher
    A crack or even seemingly benign surface penetration renders it untrustworthy. A simple ding on aluminum does far less to the integrity of the frame. Don't get me wrong, it's strong, however, it has it's drawbacks.

    carbon fiber is just that: FIBER. It has high tensile strength, but like mentioned in the Mountain Bike article, the fibers will break when stretched which constitutes a weakness.
    A crack in an aluminum frame is also bad and renders a frame untrustworthy.

    Fiber having a high tensile strength just means that it won't stretch until it has reached its breaking point. Aluminum will deform slightly at less pressure before ultimately breaking. The breaking point of carbon fiber is much higher than aluminum.

  2. #52
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    Quote Originally Posted by bdamschen
    You guys are killing me. Pound for pound, carbon is stronger than aluminum.

    If you build up a two identical frames of the same weight, one from carbon and one from aluminum, the carbon frame will be stronger.
    I am not sure "stronger" is a proper term here. If by stronger you mean resistant to stress - yield, tensile and fatigue stress, then sure, proper made carbon is by far stronger. Impact strength - I am not sure. But that is only a part of frame durability. Plasticity for example (ability to make a dent without breaking apart) is another factor. Deflection - how far will it bend without breaking - is another.

    I have little doubt that most everything that is on sale is strong enough for its purpose.

    My personal semi-educated concern about the modern state of this technology is mostly about inspection for damage. When picking up a hardtail for adventure racing I chose titanium as I think that after tossing my bike down a rocky slope at night I will be able to tell the damage on a titanium frame and keep riding it, and I would not be so sure about a carbon one. Even if the carbon one is twice "stronger" - it still breaks.

  3. #53
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    Quote Originally Posted by Curmy
    I am not sure "stronger" is a proper term here. If by stronger you mean resistant to stress - yield, tensile and fatigue stress, then sure, proper made carbon is by far stronger. Impact strength - I am not sure. But that is only a part of frame durability. Plasticity for example (ability to make a dent without breaking apart) is another factor. Deflection - how far will it bend without breaking - is another.
    From what I remember, or think I remember about carbon fiber is that in the realm of plasticity- carbon is brittle and has none it just goes straight to a breaking point, but aluminum's breaking point even after denting, is still lower than properly constructed carbon fiber. So sure aluminum would dent before breaking, and carbon would just break, but the aluminum would dent and break long before carbon.

    Deflection also sort of falls into the same realm. Carbon Fiber won't deflect much, but it will take a lot more force to break it. It will remain stiff the entire time up until failure. That failure point should be much higher than a comparable aluminum frame if I remember right.


    Good point on inspection though. I think I'd avoid a carbon frame for adventure racing just on that and carbon's susceptibility to moisture if not properly laminated. For big hits on something like a 6" AM ride or even an 8" DH bike, I'd probably feel pretty confident on carbon.

  4. #54
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    I bet this same discussion happened years ago when aluminum was the next bike material.
    Some folks probably said it will never work and they will only ride steel until they die, while others decided to give it a try.

    I bet in another 10 years, we'll be having the same discussion, but stating "I won't ride anything but carbon. That new [insert technology] is [insert fault]."

    I think all the materials have their place, and carbon is trying to prove it's useful in a 6" AM bike now.

  5. #55
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    Quote Originally Posted by El Castigador

    Factoring in the weight savings, the increased stiffness, and the better dampening of carbon, it seems to be the clear winner in every category save one: impact resistance. I'm actually pretty concerned about this since I seem to crash more frequently than most of the people I ride with.

    Should I stay with aluminum?
    You're never going to get an answer for which is better. However, I really don't think you need to stress about a carbon frame as much these days. Quality carbon frames have come a long way. Plus, you say your'e mostly XC, so I really doubt you'll be putting yourself in situations very often where you'll have a hard enough impact to really destroy the frame. The rear triangle on the Enduro is aluminum, so what impacts are you really worried about for the front triangle? If you're worried about cosmetic damage to the down tube, just put some 3M tape on it. Carbon can take blunt impacts extremely well. A sharp edged rock, however, can possibly score a carbon frame beyond the cosmetic layer. Note, this type of impact will also damage aluminum. BUT, these types of damage can be repaired by carbon frame builders. I know Calfee offers a repair service.

    Everyone can come up with tons of "what if" scenarios. What are you realistically going to be putting your bike through?

    Just curious, did you get to ride both bikes to compare the vibration dampening? I know you mentioned that's a huge plus for you.

    I own aluminum bikes, and I've ridden carbon bikes. I wouldn't hesitate to buy a carbon frame. But I'm also a lightweight and ride mostly XC. I do crash, but most of my crashes result in scrapes rather than breaks.

    The easiest solution? Just stop crashing.

  6. #56
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    Quote Originally Posted by dan51
    I bet this same discussion happened years ago when aluminum was the next bike material.
    Some folks probably said it will never work and they will only ride steel until they die, while others decided to give it a try.
    "Yeah, you stick with your fancy Coke can frame. 4130 all the way, baby!"

  7. #57
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    Quote Originally Posted by dan51
    I bet this same discussion happened years ago when aluminum was the next bike material.
    Computers and internet forums weren't around back then, but it was definatley a topic that was discussed. Remember the PK Ripper? Everyone always knocked it because "aluminum is weak and it will break." However, that had more to do with the welding technology than anything else and they've improved on that problem since then.

  8. #58
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    One of the TROGS had a mojo, after the third time the frame broke (different issues each time) he sold it and will never go back.

    I know carbon can be quite solid but I'm not sure it's there yet in the cycling industry.

  9. #59
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    Screw carbon and aluminum .........get Ti

  10. #60
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    Bamboo is hot right now -- no kidding

    BTW wish I still had my steel 83' SJ or my 3 speed 81 downhiller ... Steel is so cool! Can't tell you how easy it bends BACK into place ;-)
    Jt

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  11. #61
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    Bamboo is hot right now -- no kidding

    I know their hot right now as flooring, he he he....

  12. #62
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    Quote Originally Posted by bdamschen
    Fiber having a high tensile strength just means that it won't stretch until it has reached its breaking point.

  13. #63
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    aren't wings designed to flex?

  14. #64
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    Composite materials don't yield like homogeneous metals. That means, at a certain point in the stress strain plot, the composite material will break and not take any more strain. Homogeneous metals will keep straining after the yield point, but will not take any more stress.

    If you guys really want to learn something and not just listen to people blabbing on the internet, study up on young's modulus and how they differ between composite materials and metals. You'll understand where all these theories about composites come from.

    The main thing with composite materials is that the material does not have equal material properties in all directions (non-homogeneous). With homogeneous materials (almost all metals) you only have to worry about the thickness. With composite materials, you have to worry about the thickness and which direction the load bearing fibers are positioned within that thickness.

    All these extra variables make composite material that much harder to analyze for various load cases, so the engineers heavily rely on testing. If you wanted to know how much the tip of a metal beam would deflect if you pushed down on it with a given force, you could calculate that by hand without a calculator. If you wanted to do the same thing for a composite beam, you'd have to know the exact lay up (not just material average density, remember it's non-homogeneous) and be pretty good with a computer and super up to par on your linear algebra. You guys should all call these big bike companies and ask them how many hours they spend per bike breaking them on the test machines and using that data to better the design instead of just going with the original prototype tooling and saving money.

    On that note, I run a composite skid plate on my dirt bike and trust that thing to keep my engine from getting blown up when I'm 50 miles from camp and doing 40mph through the worlds gnarliest rocks.

  15. #65
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    Quote Originally Posted by Pimp-Al
    Bamboo is hot right now -- no kidding

    I know their hot right now as flooring, he he he....
    I saw this documentary on the discovery of a new planet called Pandora with a large deposit of new mineral called Unobtanium. Maybe look into that?

  16. #66
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    Quote Originally Posted by beaverbiker
    ***Important factual information***

    Oh great, someone who knows what they're talking about. Fun's over.


    Time to ditch all the arm chair engineering and go back to practice opening a beer with a CD.

  17. #67
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    Quote Originally Posted by dan51
    I bet in another 10 years, we'll be having the same discussion, but stating "I won't ride anything but carbon. That new [insert technology] is [insert fault]."
    Quite possible.

    Look at Boeing 787. It has been delayed since somebody was not doing layup of the wing to fuselage assembly quite right - if I remember correctly. They had to fix it with some extra layers.

    Now - do you trust some underpaid underage employee in a Chinese village to layup your headtube just right?

    I would rather trust some underpaid underage welder - that is a more developed production technique as of right now.

    Cheaper and works just fine - what's not to like? In any case - for things like handlebars carbon is certainly already well proven, we probably would be able to say the same about frames in a few years - they are just showing up..

    My only experience with composites was watching my collegues design and test a support structure for a sattelite experiment. About as cutting edge as it was a few years ago. We gave up and went with a metal construction - could not make it reproducible enough. Of course that bit was designed for operation in vaccum and withstanding launch, but then it was not made in a Chinese village either..
    Last edited by Broccoli; 03-03-2010 at 12:02 PM.

  18. #68
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    Quote Originally Posted by Curmy
    In any case - for things like handlebars carbon is certainly already well proven, we probably would be able to say the same about frames in a few years - they are justs showing up..

    .
    I might be wrong about my facts -- the I think the point is will be clear.. In 1975 your statement would have been perfectly placed as the first carbon tubes and lug frames were showing up -- the bond wasn't all that good until TREK got involved, About a decade later, luggless construction we use today was introduced. That was about 25 years ago or about the same time of the first suspension MTBs! Trek has been making carbon MTBs for over 15 years! One of my riding buddies still rides a old, old OCLV HT rim brakes and all - it is a rocket (however he is slow ;-) )

    I think it was about 20 years after CF, that hydro discs were available.. Should we wait until the brakes prove themselves ;-)

    Oh
    Jt

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  19. #69
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    since i got a C in all my material science engineering classes, i'll ask you a few questions, mainly for my own eddification:

    to what extent can FEA be used w/ a material like carbon fiber (if at all) given how complex and non-homogeneous it is? seems like applying FEA to any sort of alloy would be a relative no brainer. is carbon fiber primarly tensile strength (like steel) or compressive (like concrete), or is it both (i.e. the fiber strands provide tensile resistance, and the epoxy/resin provides compression resistance)?



    Quote Originally Posted by beaverbiker
    Composite materials don't yield like homogeneous metals. That means, at a certain point in the stress strain plot, the composite material will break and not take any more strain. Homogeneous metals will keep straining after the yield point, but will not take any more stress.

    If you guys really want to learn something and not just listen to people blabbing on the internet, study up on young's modulus and how they differ between composite materials and metals. You'll understand where all these theories about composites come from.

    The main thing with composite materials is that the material does not have equal material properties in all directions (non-homogeneous). With homogeneous materials (almost all metals) you only have to worry about the thickness. With composite materials, you have to worry about the thickness and which direction the load bearing fibers are positioned within that thickness.

    All these extra variables make composite material that much harder to analyze for various load cases, so the engineers heavily rely on testing. If you wanted to know how much the tip of a metal beam would deflect if you pushed down on it with a given force, you could calculate that by hand without a calculator. If you wanted to do the same thing for a composite beam, you'd have to know the exact lay up (not just material average density, remember it's non-homogeneous) and be pretty good with a computer and super up to par on your linear algebra. You guys should all call these big bike companies and ask them how many hours they spend per bike breaking them on the test machines and using that data to better the design instead of just going with the original prototype tooling and saving money.

    On that note, I run a composite skid plate on my dirt bike and trust that thing to keep my engine from getting blown up when I'm 50 miles from camp and doing 40mph through the worlds gnarliest rocks.
    94 Specialized Rockhopper

  20. #70
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    Quote Originally Posted by diver160651
    I might be wrong about my facts -- the I think the point is will be clear.. In 1975 your statement would have been perfectly placed as the first carbon tubes and lug frames were showing up -- the bond wasn't all that good until TREK got involved, About a decade later, luggless construction we use today was introduced. That was about 25 years ago or about the same time of the first suspension MTBs! Trek has been making carbon MTBs for over 15 years! One of my riding buddies still rides a old, old OCLV HT rim brakes and all - it is a rocket (however he is slow ;-) )

    I think it was about 20 years after CF, that hydro discs were available.. Should we wait until the brakes prove themselves ;-)

    Oh
    Yes, thank you. Finally someone who knows bike history.

    As a side note, if people saw how much load it takes to break a specialized carbon enduro, they'd be spending more time researching doctors and physical therapists than e-debates about strengths of materials.

  21. #71
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    Quote Originally Posted by Curmy
    Now - do you trust some underpaid underage employee in a Chinese village to layup your headtube just right?

    no, but I would trust some underpaid Taiwanese employee in a Taiwanese village to layup my head tube just right. Those guys know what's up.... as long as they have an american QC engineer riding their butt for anything that goes wrong.

  22. #72
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    Quote Originally Posted by dth656
    since i got a C in all my material science engineering classes, i'll ask you a few questions, mainly for my own eddification:

    to what extent can FEA be used w/ a material like carbon fiber (if at all) given how complex and non-homogeneous it is? seems like applying FEA to any sort of alloy would be a relative no brainer. is carbon fiber primarly tensile strength (like steel) or compressive (like concrete), or is it both (i.e. the fiber strands provide tensile resistance, and the epoxy/resin provides compression resistance)?
    Great questions and I'll do my best to address them for you. You can use FEA programs (like NASTRAN) for composite materials just like any other material, but behind the scenes, there are a lot more assumptions being made than with homogeneous materials. The more assumptions that go into a computer model, the higher the risk factor. In addition, any engineer who solely relies on a computer to tell him if his product will break or not should be fired immediately.If you listen to the beginning of that BOEING 787 wing testing video, you'll hear the engineer say that the testing is just to verify their computer models. The computer models have so many assumptions in there that they want to make sure what they're designing and building matches the computer model, and that the computer model matches real life load cases.

    Composite materials do very well in compression and tension, and torsion, and bending, and shear TOO. This is all due to the fact that you can put the highest load bearing pieces (the fibers) in any direction you want. If you have a tube like a drive shaft on a car that see's primarily torsion loads, you would put most of your fibers wrapped around the tube at a 45 degree angle (where the cosine and sine are equal) and the fibers will see equal load. If you ran all of the fibers at that 45 degree angle and a big rock slammed into the middle of the drive shaft (putting the fixed-fixed shaft into bending) it might not be able to take the bending load, even though it can take the extreme torsion loads. So...you put some fibers at 0 degrees and 90 degrees to take load in the transverse directions. Ultimately, and especially if you see a lot of thermal loads, is to make sure your layups are isotropic or quasi-isotropic.

  23. #73
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    Quote Originally Posted by diver160651
    Trek has been making carbon MTBs for over 15 years! One of my riding buddies still rides a old, old OCLV HT rim brakes and all - it is a rocket (however he is slow ;-) )
    I would not have bought a CF hardtail for adventure racing 15 years ago, and I would not do it now. Not much that have changed.

    Quote Originally Posted by diver160651
    I think it was about 20 years after CF, that hydro discs were available.. Should we wait until the brakes prove themselves ;-)
    Hydraulic brakes are around for ninety years - Lockheed used them for cars in 1918. Took twenty years before it was used more widely. They are still only found on expensive bikes.

  24. #74
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    Quote Originally Posted by beaverbiker
    As a side note, if people saw how much load it takes to break a specialized carbon enduro, they'd be spending more time researching doctors and physical therapists than e-debates about strengths of materials.
    Aren't you sponsored by the big "S"? If you crack or damage your bike, you'll probably have a new one the next day. unfortunately it doesn't work like that for everyone.

  25. #75
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    Quote Originally Posted by bdamschen
    no, but I would trust some underpaid Taiwanese employee in a Taiwanese village to layup my head tube just right. Those guys know what's up.... as long as they have an american QC engineer riding their butt for anything that goes wrong.
    Did not work out that well for Boeing and their wings, did it? Don't you like that a 787 you may board soon would have some patches applied.

    Useless discussion anyway. All major manufacturers make fine bikes suitable for their stated purpose, everybody sould just buy what they like. I do not shy away from carbon on a trail bike - I shy away from spending money that I can use for something else.

  26. #76
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    Quote Originally Posted by ThePunisher
    get the latest issue of Mountain Bike and read the article. it's really informative.

    If you really ride hard; sooner or later you will crash. regardless or the bike's material, if you carsh in rocks it will leave a mark. A dent on aluminum to me is less worisome than a chip in carbon.

    if you ride tigh single track with boulders; sooner or later you'll end up catching one of them with your stays.

    Lastly, have you even seen bikes after a full summer of high mountain riding in rocks? the downtube looks like it's been shot by a shot gun (eg many small dings and dents). I've even seen some with big dents near the BB.

    But will get the job done - but I personally feel safer on an Aluminum frame for this particular kind of riding.
    Dude, seriously, you should throw away all those mountain bike magazines. Those dudes are casual riders, at best, who spew garbage all over the place trying to convince people they know what they're talking about. Ask them how many years they've been a mechanical engineer designing with composite materials, and where they learned to do that. Until then, those mags are probably better for wiping your a$$ on the side of the trail.

    The top few plies on most bikes are superficial (there for looks and protection against the real load bearing plies). I'd much much rather have a nick in a sacrificial ply than a dent in an aluminum tube that causes a stress concentration and will lead to buckling.

  27. #77
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    Quote Originally Posted by ThePunisher
    Aren't you sponsored by the big "S"? If you crack or damage your bike, you'll probably have a new one the next day. unfortunately it doesn't work like that for everyone.
    You're right, but do you think I would be risking my life just for free bikes? No way. I've got a job.

  28. #78
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    Quote Originally Posted by beaverbiker
    You're right, but do you think I would be risking my life just for free bikes? No way. I've got a job.
    But you certainly would not risk damage to your wallet. I think that was his point. It is a slightly different thought process when you pay a few thousand of your own $ for something that should last you for a few years.

    As far as asking an engineer with experience with composite materials - it just happened that right now I sit next door to a guy who was working on a project I have mentioned above. He agrees with my attitude towards this - to use something else for a while - and he has no vested interest in selling those frames, unlike engineers from bike companies.

    Quote Originally Posted by beaverbiker
    I'd much much rather have a nick in a sacrificial ply than a dent in an aluminum tube that causes a stress concentration and will lead to buckling.
    True, but you can see a dent. I would rather see (or not) a dent in a titanium tube when I keep riding at night, then keep guessing it that nick was superficial or not. But that is me being a cheap bastard.

  29. #79
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    Quote Originally Posted by Curmy
    Did not work out that well for Boeing and their wings, did it? Don't you like that a 787 you may board soon would have some patches applied.

    Now I know I drink a bit more beer and eat a bit more pizza than I should, but I'm pretty sure that even with 10 extra winter pounds that I may or may not have put on, I will come nowhere near putting a carbon DH or AM bike through what a 787 wing might experience.

    I hear ya on cost though. My current AM bike is 4 years old, aluminum and has more flex out back than a 18 year old yoga student. I've hucked it off dumb stuff, crashed it into more dumb stuff and bailed on it over the transition of stuff even dumber still. I'm actually waiting for the day when it disintegrates under me through a rough section. Maybe this year I'll pick up a new frame, but chances are I won't be able to afford carbon.

    If I could though, I'd rock one with out a single doubt in my mind that it would hold up better than the heap I'm currently riding.

  30. #80
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    Wow -- beaverbiker,

    I do feel much better about my carbon wheels now! Thanks...

    Btw I am riding about 500+ miles a month and my own bones and edge of the trail concern me a lot more than engineered parts beating over the rocks.

    Curmy - I don't think anybody is in disagreement with you that AL is cheaper and maybe even a better value. I think we would all agree that someone who only cares to spend a fixed amount, might be better getting an AL frame with great suspension, wheels etc. rather than getting a 4,400 frame/fork and slapping lower end components on.

    That said, I don't think the value issue is on the table for El Castigador. I believe he looking at positives of CF such as increased stiffness, and the better dampening; but is concerned about the impact resistance of CF.

    Taking money completely out of the issue, well designed and built CF wins over thin wall AL..

    The only question El Castigador should ask himself is "If I crash hard enough or unlucky enough to kill a AL or CF frame can I afford to replace it? "

    BTW I was talking about the sram BIKE hydros not cars..
    Jt

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  31. #81
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    Quote Originally Posted by Curmy
    But you certainly would not risk damage to your wallet. I think that was his point. It is a slightly different thought process when you pay a few thousand of your own $ for something that should last you for a few years.
    Obviously I care about spending money as I am not rich, but I care much much more about my boyish good looks than I do about how fat my wallet is. If I thought it was dangerous to my health and facial features to ride the carbon one, I'd ride the aluminum one. If you wreck super hard and you break your bike, you'll probably be spending a lot more on hospital bills and pain and suffering than the cost of buying a new bike. Specialized doesn't pay my medical bills, but at least they can give me super solid and dialed bikes to test out instead of some sketchy plastic thing designed in international waters by pirates.

  32. #82
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    Quote Originally Posted by Curmy
    As far as asking an engineer with experience with composite materials - it just happened that right now I sit next door to a guy who was working on a project I have mentioned above. He agrees with my attitude towards this - to use something else for a while - and he has no vested interest in selling those frames, unlike engineers from bike companies.
    Is that guy the one that was trying to build a support structure out of composites? What happened? I'm not trying to start a war, just curious. I happen to be in the same industry...

    What your buddy was probably telling you was to stay clear of first generation things as they are not proven and you should "use something else for a while" until they get it dialed in. And I pretty much agree with that for the most part. The thing is, Specialized and other bike companies have been making composite bikes for a very very long time. And other companies, like the one I work for, have been building things that are even bigger and badder than a bicycle, out of composites for 50 years. This stuff ain't new and unproven. It's easier for most people to layup some composite brackets and bolt them together than it is to machine the parts out of metal and weld them together. Less chance of voids too...

  33. #83
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    DAMPING - to absorb energy
    DAMPENING - to get wet (like with water)

  34. #84
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    Quote Originally Posted by beaverbiker
    Is that guy the one that was trying to build a support structure out of composites? What happened? I'm not trying to start a war, just curious. I happen to be in the same industry...
    It was hard to build, test and validate and did not bring enough benefits to spend more money on it.

    Quote Originally Posted by beaverbiker
    What your buddy was probably telling you was to stay clear of first generation things as they are not proven and you should "use something else for a while" until they get it dialed in. And I pretty much agree with that for the most part. The thing is, Specialized and other bike companies have been making composite bikes for a very very long time.
    No, for me it is not a question of quality or being a first generation. It is a simple cost/benefit analysis. I do not see any tangible benefits to the long travel full suspension frames so far to justify acquisition and possible maintenance and replacement costs. As I have mentioned in this thread - stiffness seems to be the function of suspension and pivots design - and there are plenty of cheap frames that are strong and stiff enough (my Coiler feels stiffer then Mojo I have ridden, not that I obsess over that). "Damping" does not seem to be of any importance for the wall thickness they use, and given that I have 160mm of plush suspension on both ends.

    For a weenie hardtail I certainly see benefits, but then my very specific use case (adventure racing usage at night) makes titanium my material of choice. It is a more resilient material with a minimal weight penalty, comparable cost, arguably better comfort level of riding and sufficient (for me) stiffness.

    For an AM hardtail I went with steel (TransAm). Slack and strong. I am not aware of CF alternative to that genre of frames.

    Cost/benefits - not paranoia.
    Last edited by Broccoli; 03-03-2010 at 03:39 PM.

  35. #85
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    I have a GT Force Carbon. No issues.

  36. #86
    Ride what you want!!
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    Quote Originally Posted by 0gre
    One of the TROGS had a mojo, after the third time the frame broke (different issues each time) he sold it and will never go back.

    I know carbon can be quite solid but I'm not sure it's there yet in the cycling industry.
    Yup... he broke 3 mojos...first one he just flopped over sideways going slow picking his way through a rocky line on a trail and a rock poked a hole in the stay... that's the one I witnessed... the other two I never saw...

    Carbon is for road bikes.
    Trogs: Too Tough for Carbon Fiber

  37. #87
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    When I look at it? It comes down to money. I would love a Fuel 9.9EX or a Remedy 9.9, but I cannot justify the money when I will want something new in 7-8 years. Also you cannot even buy just a frame and put all the cool upgrades you may have on your existing bike onto your new frame. So I am looking at a Camfiled Bro's One frame. I have had only the chance to test ride the oclv frames and they feel sweet. Just way out of the price range. So based on your situation it differs for everyone. If you get caught up in the which one can outlast the other Carbon or AL...you will have a nervous break down. They are both great and if there is a serious problem you will have to deal with the manufacturer. Research that? How is the manufacturer going to take care of you if its on there side?

  38. #88
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    fter yesterday's soggy demo ride at Demo, I'm sold on the carbon Enduro. Even with the 66 degree HT angle, and a 36T "middle" ring, it hammered up the muddy Sulpher Springs easily. It feels quite a bit livelier and stiffer than the Alu version, and feels beefy enough to calm my carbon paranoia.

    Braille was a lot of fun too! The teeter-totter toward the top was a little slow to actuate, so it turned into a 3' roller instead. Pretty sure I would have gone OTB on my old Enduro.

    Anyone know if there are any changes to the frame planned for 2011?
    Attached Thumbnails Attached Thumbnails I need advice, Carbon or Aluminum?-1.jpg  

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  39. #89
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    None of the above

    For the price of a carbon frame you can pick up a titanium frame on clearance that will last a lifetime, never dent or crack and only be a slight weight increase over aluminum. Yes a titanium frame will be heavier than either and be less stiff, however the flex in it will also make it far more durable. Also the frame being flexible will absorb some shocks from the trail.

    (Note, a thick side walled 7075 aluminum t6 or t651 temper will hold up relatively well also. However you risk denting or fracturing the frame with extended use. Keep in mind lighter frames generally mean easier to break frames. Lighter might sound better but do you think your going to notice a few extra pounds biking compared to a few less pushing.)

    (PS you can pick up titanium frames online for $400-$500)

  40. #90
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    Good info Andrew. I am sure the OP still hasn't made his mind up 2 and a half years later and will appreciate your input.

  41. #91
    It's about showing up.
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    Well, we have to consider catratrophic failure vs. fatigue. Oh, wait, this isn't 2001. Nevermind.
    I don't rattle.

  42. #92
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    How many of us have carbon bikes now? I have and still do

  43. #93
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    Quote Originally Posted by andrew hild View Post
    (PS you can pick up titanium frames online for $400-$500)
    Out of curiosity, where can one pick up titanium frames online for $400-$500? Are we talking new or 10-15 years old? direct from China or US retailer?

    I'm not being contrarian here; I am in the market for 1 & want to know where these deals are!

    Thanks!

    LJ

  44. #94
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    Quote Originally Posted by Shwaa View Post
    Good info Andrew. I am sure the OP still hasn't made his mind up 2 and a half years later and will appreciate your input.
    hey lippy, your on the forum so clearly people are still interested in the topic.

  45. #95
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    TI frames

    Quote Originally Posted by skyno View Post
    Out of curiosity, where can one pick up titanium frames online for $400-$500? Are we talking new or 10-15 years old? direct from China or US retailer?

    I'm not being contrarian here; I am in the market for 1 & want to know where these deals are!

    Thanks!

    LJ
    It has been a while since I have looked, I have seen them before on clearance or holiday sales, you just have to check a lot. Used you will be hard pressed to find one but there out there. Sorry but I don't remember the site names. Yes by the way they were cheap and probably foreign frames.

  46. #96
    I just wanna go fast!
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    Still on an aluminum frame, but at least a new one now. I'd be riding carbon but I still can't afford it since I have to buy the wife a new frame every time I buy a new frame.

  47. #97
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    Recently, I was considering my steel frame for an aluminum one. It would be a hardtail XC to replace my On-One Inbred.

    Back in the good ol' BMX days, we'd break frames all the time (4130 chromoly). The amount of abuse that our 20" bikes would go through was ridiculous, and I did this as a stocky 14 yr. old. Whenever they would break, we'd grab our allowance money and take it over to Paul Sadoff at Rock Lobster, and for a few bucks, he'd repair them for us and we'd be on our way.

    So, as a 220lb. 38 year old adult who really, really, really likes doing stupid things on MTB's - I've decided that I'm just going to stick with my steel bikes. In fact, I own nothing but steel. There is a weight penalty, and FS doesn't come in steel, but I'm sticking with it. I'm slow as it is, and watching Leopold Porkstacker stay consistent as a local Strava Leader here in SJ, I think that this bike is much better than me.

    However, given my weight, if I were to "upgrade" I'd go with aluminum. Some of you skinny kids, even when riding hard, probably don't stress a frame like I would. Maybe this is just all in my head, but part of the equation is believing your bike isn't going to fail you - and on the mental aspect of MTB'ing I think that means a lot.

    As much as I love the idea of carbon - I think I'd be nervous as a heavyweight riding it. Even if it could handle me, the idea of it breaking would always be on my mind.

  48. #98
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    Quote Originally Posted by Dion View Post
    Maybe this is just all in my head, but part of the equation is believing your bike isn't going to fail you - and on the mental aspect of MTB'ing I think that means a lot.
    <iframe width="560" height="315" src="http://www.youtube.com/embed/xreZdUBqpJs" frameborder="0" allowfullscreen></iframe>

    Quote Originally Posted by Dion View Post
    FS doesn't come in steel
    You have to go boutique. There are others, but here's two.

    the Product of COTIC cycles : droplink ROCKET

    SyCip Full Suspension Bikes - Handcrafted in Sonoma County, California
    Last edited by IAmHolland; 11-28-2012 at 01:29 PM.

  49. #99
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    A interesting carbon failure.

    <iframe width="560" height="315" src="http://www.youtube.com/embed/hgRNYuFewS4" frameborder="0" allowfullscreen></iframe>

    Even after seeing that video I'm not concerned with using carbon. Most bikes these days are designed well enough that catastrophic failures are very rare, no matter the material. My biggest issue with carbon is cost and even that is slowly changing. As Dion pointed out the limiting factor is usually the rider and not the bike.

    The choice between carbon or other materials also depends on what you are looking for in a bike. For me carbon makes sense for a hardtail but AL is best for a FS. I have ridden AL HTs for years and they are stiff and strong. It wasn't until I demo'd a carbon HT that I realized how stiff and abusive the ride of a AL HT is. My new XC race bike will be carbon because I want it light and with a softer ride. But Ti or steel will get one a softer ride than AL at less cost than carbon. For a FS trail bike I'll stick with AL, an FS frame needs to be as stiff as possible to let the suspension do the work and not the frame. So either AL or carbon fits the bill. Next is weight, with a trail bike I'm not looking for the lightest thing around. Also, the weight difference is minimal, usually a pound or two. For me the big driver is cost, a carbon FS frame is 1.5-2X the cost of AL. I'd rather use that money for something else wheels, suspension, etc.

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