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  1. #1
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    New question here. Carbon Fiber bars...

    Just picked up my first DH, a 2016 Carbon Fiber Kona Supreme Operator, coming from a Santa Cruz Bullit of 15 years, lol. Anyway, I had carbon fiber handlebars on my Bullit and they held up to some hard riding, but it was not DH, so two ?'s
    1)Is it a good idea for DH?
    2)Can carbon fiber be cut with a hacksaw/filed square and smoothe just like aluminum to get to the preferred width?
    Any other info I am not thinking of would be helpful, thanks!

  2. #2
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    1. Yeah, they're fine for DH as long as you aren't getting dubious chinese carbon stuff from Alibaba. Get a reputable set and you're good to go. I run Enve M7s and am happy with them.

    2. Yes, but you need a different blade for carbon fiber. It's also a really good idea to wear at least a paper painter's mask when cutting CF, because the particles are super fine and will do all sorts of terrible things to your lungs. I use this blade here:

    https://www.parktool.com/product/carbon-saw-blade-csb-1

    As a side note, you should get a few park days under your belt before you cut them down. I find that I like my DH bars a bit wider than my XC/Enduro bike bars, it makes it a little easier/more natural to keep a nice wide grip/stance which is important for DH. Wider bars can help you avoid having t-rex arms, where your elbows drop down to your sides like you're doing bicep curls instead of spreading your arms out like you're doing a push-up.
    Trail: Scalpel-Si / Sherpa / Fatboy
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  3. #3
    Glad to Be Alive
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    would never chance it...seen the best and either there was a crack you didn't see or something so small like not using a torque wrench and over tightening and snapped you are hurt or even in the hospital....we ride crazy stuff and at speeds....that is just me but this is my experience
    the trick is ENJOYING YOUR LIFE EACH DAY, don't waste them away wishing for better days

  4. #4
    Professional Troll
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    Quote Originally Posted by SHIVER ME TIMBERS View Post
    would never chance it...seen the best and either there was a crack you didn't see or something so small like not using a torque wrench and over tightening and snapped you are hurt or even in the hospital....we ride crazy stuff and at speeds....that is just me but this is my experience
    This is just paranoia. Properly installed bars that are made correctly (I.e. any major brand) will be just fine. I run carbon bars on all my bikes. Even my downhill bike that Iím blasting 40 foot jumps on.

  5. #5
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    I've seen both carbon and aluminum bars snap. If you are going big and riding fast I think swapping out the bar once a year is warranted for either material.

  6. #6
    Ricky DH
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    IMO, even tho they make airplanes out of the stuff, I'd stick with aluminum. While I'm sure it's happened, I've never seen aluminum bars explode/fail the way carbon will. Like I said, this is just my opinion.

  7. #7
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    I'm a supplier to the composites industry and the technology has gotten WAY better over just the last 3-5 years for impact resistance. A straight bis-a epoxy thermoset from 10 years ago? Hellsno! But todays carbon bars are FAR stronger than aluminum bars with excellent impact resistance. In fact I can say with confidence that any DH carbon bar from a major manufacturer (like Deity) will be much more durable than ANY aluminum bar! This isn't opinion, conjecture or blowing smoke... the resin modifiers, coupling agents, crosslinking catalysts end even thermoplastic fillers and carbon fiber type and orientation have all had a HUGE impact on composite integrity and I've seen the tests that prove it.

    Have FUN!

    G MAN
    "There's two shuttles, one to the top and one to the hospital" I LOVE this place!!!

  8. #8
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    We should be well beyond asking this question by now. Your frame is carbon, no reason why your bars shouldn't be.

  9. #9
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    Update...purchased Answer Protaper 780mm Carbon bars three weeks ago after reading everyone's replies, even the smart-ass ones lol. I had a hard time finding the torque specs as they varied, but ended up determining 4-6Nm as one reply also said (thanks!). I was told I should use carbon grip goo, but the bars already had a grip area built-in. 18 rides later, stoked it came out as it did. Also, met two other DH riders while riding, both raced and had issues with both carbon and alloy bars failing mostly at or near the stem clamp, told me it seems over-torqueing carbon most common cause on carbon, or cheap mfg, then on alloy bars, riding them after a hard hit. Either way, replace. Both of them were riding carbon bars, one on a Canyon endure, the other on a Santa Cruz DH. Anyway, thanks for the advice!

  10. #10
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    ^^ 4 N*m MAX and make sure your stems' clamp has had the sharp edges sanded down.

    Have FUN!

    G MAN
    "There's two shuttles, one to the top and one to the hospital" I LOVE this place!!!

  11. #11
    damned rocks...
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    I installed my Protaper 810mm Carbon with 4Nm, had a crash three rides later, the crash was hard enough to send me flying over the bars and rotate the stem on the steer tube, damn stump didn't got out of the way .
    But the handlebars didn't rotate on the stem, the grip area seems to work really well.

  12. #12
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    If your bars are 35mm, they can provide much greater clamping forces than the smaller sizes.

    The purpose, in my opinion, for the larger bar diameter is only for more clamping area to reduce the torque required to hold the bars.

    The surface contact area is greater of a 35mm bar. Think of it like holding the bar with a finger and thumb then twisting the bar. Now hold it with 3 fingers and a thumb, you can squeeze it with less force and still not twist the bar.

    The lesser torque spec is less likely to crack the carbon when cinched down.

    It sounds wrong in the brain to think about bolts so loose holding things so secure. I know I struggle with that. I want to get a torque wrench for nothing more than bar clamp and seat clamp torque. ha

    The theory of the larger bars is similar to the motorcross world and inverted forks. The triple clamp can clamp around the larger diameter of the fork legs for more clamping power than the smaller stanchion tube.

  13. #13
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    ^^Great info guys! And yeah, most of those new bars have clamp areas that are now coming roughened up. I believe they just add a strip of silica infused prepreg at the clamp area before final baking/cure. It has worked out really well with no need for carbon paste!

    Cheers,

    G
    "There's two shuttles, one to the top and one to the hospital" I LOVE this place!!!

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