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  1. #1
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    Carbon Seatpost in carbon frame

    My wife has an '05 Trek Fuel 98 with an Easton EC70 seatpost. Regardless of how tight I tighten the seat collar she still experiences some slippage. We have done the following:

    1. Mark seatpost location by wrapping electrical tape around the post.
    2. Re-greased the threads on the seat collar bolt.
    3. Grabbed a handful of dirt and rubbed it onto the post prior to insertion

    Any other tricks out there I am not employing; anything I need to try prior to spending money? Does anyone know where I can get a supplemental seatpost clamp (just a plain clamp that fits onto the post itself; a la Paris-Roubaix roadie style...see image)?

    Thanks for any advice...and no, neither the seatpost or frame is greased.
    Attached Images Attached Images

  2. #2
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    Reputation: rockyuphill's Avatar
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    Tacx carbon friction paste
    I'm a member of NSMBA and IMBA Canada

  3. #3
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    I second the carbon paste, but also pull off the seat collar and lube the inside of the collar (the part that makes contact with the frame)
    If you have a QR collar, ditch it for a bolt on.

    make sure the post is the correct size, I bought an Easton EC90 road post in 27.2mm for my road bike, after it continually slipping I pulled it used a micrometer and it measured in at 27.0mm, but was labled 27.2 on the post itself.

    A collar like on the felt pictured is a great idea if you can find one in your size


    On aside note, how is this related to brakes? did you post in the wrong forum?
    Quote Originally Posted by thefuzzbl
    aluminium has a tendency to fail when you need it most. i.e. you end up with a bad day.

  4. #4
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    It would have made waaay too much sense to post this in a forum about seatposts.


    Thanks for the advice.

  5. #5
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    Maybe you got confused by "brake time" and "break time," which will happen if you clamp down on that seatpost too hard. They're fairly easy to overtighten and crush completely.

    Double check you haven't crimped your seatpost already, and that it's a uniform diameter. It may already be broken and will never tighten down properly.

    2 things:
    +1 for some sort of carbon paste. I use Finish Line Fiber Prep.
    Second, are you absolutely sure the seatpost is the right size for your seattube? Sometimes bikes come stock with the wrong sized seat post. Not often, but it happens.

  6. #6
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    It could also be that I was surfing the disc brake forums and thought "oh yeah, I should ask that question about carbon seatposts in carbon seat tubes, and see if anyone has any ideas", then I clicked "new thread"

    I am generally very careful when torquing down bolts that involve carbon parts. It is only with the metal parts that I follow the torque specs of tighten it until it breaks and then back it off a quarter turn.

  7. #7
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    are you using a QR seat collar or bolt on?
    Quote Originally Posted by thefuzzbl
    aluminium has a tendency to fail when you need it most. i.e. you end up with a bad day.

  8. #8
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    Had a similar issue. Tacx carbon paste works like a dream and will solve your problem.
    "Confidence is the feeling you have before you fully understand the situation".

  9. #9
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    Yeah...the carbon assembly compound seems to be the concensus. I borrowed a dolap from the local shop yesterday. We'll see if it does the trick.

    Thanks again.

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