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  1. #26
    Bicyclochondriac.
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    Quote Originally Posted by Zachariah
    Constant stress(weight, clamp pressure) on a CF post is almost like incorrectly torqueing your stem, using carbon bars on a MTB. The eventual result is not pretty.
    No, over-tightening the seat clamp is like over torquing the stem, and the result is not pretty.

    As far as fatigue life, I believe CF generally has aluminum beat.

    Are CF posts as strong as a Thomson? No, but neither are 99% of aluminum ones.

  2. #27
    MEDBLKANOSCBLT2RP23
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    So, who runs a carbon or part carbon rear derailleur?

    Makes as much sense.
    RTR

  3. #28
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    Quote Originally Posted by Curmy
    For stems and seatposts there is only one choice - Thomson.
    I've "[SIZE="4"]up[/SIZE]graded" from a Thomson:

    (never been happier)

    Still using my Thomson post though...I'll have to agree that they own that market.

  4. #29
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    Quote Originally Posted by kapusta
    As far as durability, I would have no concerns. I think the stories of them failing are far overplayed. Aluminum fails as well (bars, frames, you name it). CF is very strong.
    In a strength to weight ratio around 5-12x or so more than alu. Aluminum is like wood. We used wood 100 years ago.
    Quote Originally Posted by Curmy
    Carbon is a fad.
    Quote Originally Posted by robicycle
    Just lube your ass with asscream and ride for how long you want.

  5. #30
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    I broke an aluminun seat post on my road bike, just before a metric century, that I had prepaid for. I was just a little dissappointed. I really did not like a jagged piece of aluminum pointed up at my tender spot for about a mile!!!

    I guess if they make we can brake it.

    wn

  6. #31
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    Unobtanium is the answer
    Quote Originally Posted by Curmy
    Carbon is a fad.
    Quote Originally Posted by robicycle
    Just lube your ass with asscream and ride for how long you want.

  7. #32
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    I have the EC70 seatpost, it's full of scratches, including some very deep ones, from having tried to lower the saddle for a technical descent. It was 1 day old. I still use it, but I wouldn't want to buy another CF post again.

  8. #33
    some know me as mongo
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    have any of you guys seen a F1 car lately??? just about the whole thing is carbon now and they almost never fail mechanically and when they do its almost always a metal part.

    don't fear carbon, just bad designer. <-- i hate to say it but many of these parts on the market really have little real engineering behind them.

    Dekes you need to deburr the inside of you seat tube. i have had that happen before as well. i deburred the frame and it never happened again.

    also to the thomson lovers out there. they are great post for sure but i have bent more than one now and have had any posts stand up to more abuse.

  9. #34
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    A well designed/built CF part will surpass AL. on weight, strenght, fatigue.....look at the new Airbus plane 80% CF, F1 cars 90% CF, Helicopters, more planes, speed boats... And the use of CF has been extended to not only body parts, but critical parts like, suspension components, drive shafts, mounts........the use of CF on road bike is esxtensive, not the same on mountain bike because is cheaper to deal with metals.

  10. #35
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    LOL, I am no carbon hater but bad example.....I shoot a ton of motor sports and those cars disintegrate instantly once they drift off the tarmac

  11. #36
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    Quote Originally Posted by sir_crackien
    also to the thomson lovers out there. they are great post for sure but i have bent more than one now and have had any posts stand up to more abuse.
    i think that probably reflect more about you than Thomson.
    .

  12. #37
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    yes....if you see a F1 car hiting a wall at +200mph you will see pieces of CF all over, thats because CF when compresed to its limits will break, on the other hand metals will bend and break too, metals will fail its integrity like CF does. No one is saying that CF is the miracle material that does not break......it will break like anything else.......look at Lahar bikes 100% CF pure DH bikes, the new GT DH 100% CF..... CF compared to metals is new to the world no more than 30 years compared to 1,000+ years of metals.
    Each day CF is getting better.

  13. #38
    Flying Goat
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    i'm running a carbon road seatpost on my race bike... havent had a problem yet...



    As for stems, got a Sunline Boxxer Stem coming... Think it's way better than a thompson... For my intended use anyways...

  14. #39
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    Quote Originally Posted by Ray Lee
    LOL, I am no carbon hater but bad example.....I shoot a ton of motor sports and those cars disintegrate instantly once they drift off the tarmac
    As they would if they were made out of any metal alloy. If they were any stronger than they needed to be to stay on the track and win they would be too heavy to be competitive. The carbon tubs survive pretty much everything and I don't see the FIA calling for a change in material to make things safer.

  15. #40
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    I roll with a Carbon seat post, stem, and handle bars. So for so good. It's hard to explain but I like the feel of the carbon bars.
    FSA Carbon Kforce riser bars.
    FSA Carbon SLK seatpost.
    Q2 Carbon Stem.



  16. #41
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    The term "All Mountain" was destined to fail.

    You are posting that in the AM forum. It could be said that AM is riding all over the mountain. That's actually cross country. AM is a more aggressive XC/light FR type of thing. Your IH is built like an XC/Trailbike.

    I don't say this to be a dork...just trying to preserve the classification for some reason even though I was against it in the beginning.

    Freeride:



    All Mountain:



    XC:



    Basically saying that you roll with carbon has little bearing on the rigors of light FR / Aggressive riding. Hope I'm not being confusing or offensive.

  17. #42
    some know me as mongo
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    scottzg say what you want but at 260 lbs i'm very hard on parts because of my weight not because of lack of riding skill.

    in my opinion thomsons are like kings. good products but very over rated and they have gotten this god like symbolism about them when in reality they have done little to nothing to actually advance or farther their product.

  18. #43
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    It was joke!!!!!!!! let me try and make it more simple for you

    First this is a mountain bike forum as in off road.....when a carbon bodied car goes off track (not into a wall) just through the infield (dirt/grass or combo of both) a nice long trail of carbon fiber part are left for a hundred feet behind....

    Just a dumb joke, but really the F1 thing was not really the best example of carbon fibers strengths

    Good luck guys, I am sure you will be able to get this carbon vs. aluminum thing all sorted out......after that maybe you can tackle deeper issues like what is "all mountain"

    Ray


    Quote Originally Posted by petercarm
    As they would if they were made out of any metal alloy. If they were any stronger than they needed to be to stay on the track and win they would be too heavy to be competitive. The carbon tubs survive pretty much everything and I don't see the FIA calling for a change in material to make things safer.

  19. #44
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    I dunno about carbon for "AM" posts- AM bikes tend to need quite a bit of exposed post and subject it to rougher trail, and carbon posts tend to be marketed to the XC set. I'm sure you could build a post out of CF that would be plenty strong for the application, but i raise and lower my saddle on my AM bike pretty frequently, and i don't think CF would like all the abrasion. It really seems like an alu post makes more sense here.


    Quote Originally Posted by sir_crackien
    scottzg say what you want but at 260 lbs i'm very hard on parts because of my weight not because of lack of riding skill.

    in my opinion thomsons are like kings. good products but very over rated and they have gotten this god like symbolism about them when in reality they have done little to nothing to actually advance or farther their product.
    Even at 260lbs if you're gonna be bouncing your ass on the saddle hard enough to break several VERY strong seat posts... you're doing something wrong. Try transferring your weight to your legs when it gets rough.

    as far as thomson and king never changing their product, both are making a product that has been widely tested and known to be of excellent quality. When you buy thomson or king you know exactly what you're getting- if they were constantly futzing with the design they would lose a powerful selling point.
    .

  20. #45
    My bike is cooler then me
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    I got a Thomson seat post stickin out of a CF frame... they seem to get along.
    This might have been said already…

    From a material stand point I'm thinking the reason we hear lots of seat post fracture is due to the marring of CF rod when a rider moves it a lot or over tightens with a quick release… the seat post seems to be a place of high operator (trail) error. And in the AM life style, myself at least, tends move it a lot.

    CF is fine, but AL is a better investment.


    * EDIT* yeah repeating what was JUST said... +1 for my lack of reading skills
    '09 Cannondale Moto Carbon 2

    'is that a Thomson in your pocket, or are you just happy to see me?'

  21. #46
    some know me as mongo
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    first do you even watch F1? if you did you would now that they end up in the infield more than they would like, like in this last race. not one of them failed do to just going into the infield. everyone broke because they hit a wall or were hit by another car! also the F1 car is completely relevant because of the loads, forces, and the intensity that they happen at all far exceed what any mtber could ever product. also the F1 engs. are by far are on the leading edge of carbon composites technology. they always have to come up with the lightest, strongest, and most aerodynamic solution. also by new F1 rules i believe that have to use the same chassis for at least 3 races now. that is a feat in-and-of-itself.

  22. #47
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    Quote Originally Posted by Ray Lee
    It was joke!!!!!!!! let me try and make it more simple for you

    First this is a mountain bike forum as in off road.....when a carbon bodied car goes off track (not into a wall) just through the infield (dirt/grass or combo of both) a nice long trail of carbon fiber part are left for a hundred feet behind....

    Just a dumb joke, but really the F1 thing was not really the best example of carbon fibers strengths

    Good luck guys, I am sure you will be able to get this carbon vs. aluminum thing all sorted out......after that maybe you can tackle deeper issues like what is "all mountain"

    Ray

    Look. I'll make it simple for you. If that's your idea of a joke, you shouldn't give up your day job.

  23. #48
    some know me as mongo
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    Quote Originally Posted by scottzg
    I dunno about carbon for "AM" posts- AM bikes tend to need quite a bit of exposed post and subject it to rougher trail, and carbon posts tend to be marketed to the XC set. I'm sure you could build a post out of CF that would be plenty strong for the application, but i raise and lower my saddle on my AM bike pretty frequently, and i don't think CF would like all the abrasion. It really seems like an alu post makes more sense here.




    Even at 260lbs if you're gonna be bouncing your ass on the saddle hard enough to break several VERY strong seat posts... you're doing something wrong. Try transferring your weight to your legs when it gets rough.

    as far as thomson and king never changing their product, both are making a product that has been widely tested and known to be of excellent quality. When you buy thomson or king you know exactly what you're getting- if they were constantly futzing with the design they would lose a powerful selling point.
    when did i ever say break. i said bent. maybe you should ask me the problems i have had before coming after me. the thomsons i have bent, one was on me dh bike and was from a somewhat botched landing and the other was on my xc bike and because i'm pretty freaking tall as well i have to have alot of post showing on the bike. it bent slightly when there was and unexpected divot in the ground. the other post that i have had problems with were ritchey comp post. they were just crappy post in general. i have had great success with truvative team post. they are just plain bullet proof and light. i have used atleast 4 now on different bike and not one has failed. i have one on my dh bike and tore the seat off of it, but ti rails bent all up. the seatpost is fine, other seatpost i have had would of needed replacing.

  24. #49
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    Quote Originally Posted by sir_crackien
    when did i ever say break. i said bent.
    That's one of the nicest things about Thomson posts - they bend instead of shattering. Build-in point and mode of failure.

    Thomson makes by far and away the best seatposts on the market - including the lightweight category.

  25. #50
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    I have one

    Easton EC 90 31.6 on my FXR and I'm not impressed. It was on the bike that I bought used or I'd never drop $200 on a seatpost. It's not that it does anything too bad but they are expensive, tend to require a tighter clamp or they slip and they don't save much (if any weight over a Thompson, especially a Masterpiece, which is still less than an ec90. If you have the $$ and a carbon fetish I understand but my $$ goes to Thompson.

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