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  1. #1
    Senior Member Sundance89's Avatar
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    Carbon fiber "wrapped" seatpost. Torque wrench necessary?

    I picked up a FSA Carbon Pro seatpost. It's really 6061AL "wrapped" with carbon fiber for added strength.

    Question: Can I just blast away and tighten this thing down as with any other aluminum seatpost, or do I have to handle the carbon fiber "wrap" on this with the same care as full carbon?

  2. #2
    Pwnerer Wordbiker's Avatar
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    The torque wrench is needed more for the clamp than the post.

    You will want to install it with Tacx assembly lube (or another similar product) to prevent slipping and galling instead of grease.
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  3. #3
    Senior Member Sundance89's Avatar
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    Quote Originally Posted by Wordbiker View Post
    The torque wrench is needed more for the clamp than the post.
    Interesting. I had a full carbon (Specialized Pave) seatpost on an aluminum frame and my Specialized dealer was adamant about using a torque key to not damage the seatpost?

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    Senior Member Sundance89's Avatar
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    I guess I should add that this FSA seatpost is going on an aluminum frame (Xtracycle build) as well.

  5. #5
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    Sounds like the worst of all worlds for seatpost construction. The torque sensitivity and slipperyness of carbon and the weight of aluminum.

  6. #6
    Senior Member Sundance89's Avatar
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    Quote Originally Posted by HillRider View Post
    Sounds like the worst of all worlds for seatpost construction. The torque sensitivity and slipperyness of carbon and the weight of aluminum.
    Yeah, it is kind of a gimmicky design. I'm just hoping I can tighten it like any other aluminum post (aside from using Tacx lube). There were only so many 31.6 seatposts out there. This was on sale for a really low price and I like how it looks. It certainly goes with the lollipop red powder coat frame, and black rims with red nipples wheelset I have.

    My only concern is will I crack the outer carbon wrap in some sort of weird way if I over tighten this? I do have a torque key that I could keep on the Xtracycle if it comes to that I guess?
    Last edited by Sundance89; 09-26-11 at 08:38 AM.

  7. #7
    Senior Member Sundance89's Avatar
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    Well here's my deduction. I will assume by having AL at the center of the seatpost, this will eliminate the carbon wraps ability to flex and break. And because carbon fiber is basically plastic, it's not going to crush and break like glass against the aluminum when pressure is added. So I'm opting to be less cautious on tightening.

    If I suddenly find that I can sing falsetto like the Bee Gees, you'll know why. (And just shoot me if that happens too.)

  8. #8
    pmt
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    Quote Originally Posted by Sundance89 View Post
    I picked up a FSA Carbon Pro seatpost. It's really 6061AL "wrapped" with carbon fiber for added strength.

    Question: Can I just blast away and tighten this thing down as with any other aluminum seatpost, or do I have to handle the carbon fiber "wrap" on this with the same care as full carbon?
    Why would you think you could eschew the proper tool even if it was plain aluminum? Unless you've worked in a bike shop as a mechanic for twenty years and can do it by feel, you should use a torque wrench anyway.

    Even the pros should use a torque wrench as well, but let's not get into that discussion as it's already been hashed out many times here on BF.

  9. #9
    coprolite fietsbob's Avatar
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    Make sure the frame tube ID is smooth, Carborundum paper or cloth around a dowel ,
    inside the seat tube. so you don't unnecessarily gouge the post.

  10. #10
    cab horn
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    1) use carbon assembly paste
    2) collars are usually 5nm unless otherwise noted...
    Mes compaingnons cui j'amoie et cui j'aim,... Me di, chanson.

  11. #11
    Biking Viking. goatalope's Avatar
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    I've used the Ritchey torque key before. And then used a regular allen wrench. It seemed to me that by using a normal length allen wrench and tightening it to the point where there is resistance but you're not straining at all, I could achieve pretty darn close to the 5nm of the torque key.

    I don't think tightening this Al/C seatpost is a big deal. Just use a friction paste and tighten with an allen key at a reasonable level.
    Tuesdays I work on my hair helmet.

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