twisting handlebar with aero bar

Discussion in 'Cycling Equipment' started by [email protected], Jul 13, 2005.

  1. I have clip on aero bars on my handlebar and I can't get the stem clamp
    on the handlebar tight enough to maintain the position of the
    handlebar. Normally, the handlebar stays in position but when I'm
    riding on the aero bars (which is the norm) and I hit a bump, I hear a
    little click noise and the handlebar rotates downward which puts my
    aero bar out of position (tilted down). I've tried re-positioning the
    handlebar and re-tightening as tight as I can but the handlebar
    continues to rotate when I hit a bump.

    So I'm forced to conclude that there is not enough friction between the
    stem clamp and the handlebar. I've considered that maybe I need to
    remove the stem clamp (it's threadless and easy to do) and sandpaper
    the clamp to roughen it. Or perhaps I could insert double-sided
    sandpaper to give some grip.

    Anybody else have this problem and any suggested solutions?

    Denis
     
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  2. [email protected] wrote:
    > I have clip on aero bars on my handlebar and I can't get the stem clamp
    > on the handlebar tight enough to maintain the position of the
    > handlebar. Normally, the handlebar stays in position but when I'm
    > riding on the aero bars (which is the norm) and I hit a bump, I hear a
    > little click noise and the handlebar rotates downward which puts my
    > aero bar out of position (tilted down). I've tried re-positioning the
    > handlebar and re-tightening as tight as I can but the handlebar
    > continues to rotate when I hit a bump.
    >
    > So I'm forced to conclude that there is not enough friction between the
    > stem clamp and the handlebar. I've considered that maybe I need to
    > remove the stem clamp (it's threadless and easy to do) and sandpaper
    > the clamp to roughen it. Or perhaps I could insert double-sided
    > sandpaper to give some grip.
    >
    > Anybody else have this problem and any suggested solutions?
    >
    > Denis


    I've been able to increase friction between the stem clamp and
    handlebar to reduce slipping. I used 80 grit emery cloth to rough up
    the mating surfaces on both the stem and bar, sanding longitudinally
    (though I don't know if that's important).

    Also, cleaning the mating surfaces with alcohol or acetone may help. It
    certainly helps carbon seat posts stay put!

    Also, greasing the bolt (threads and shoulder) should help. Don't over
    tighten.

    Good luck!
     
  3. Martyn Aldis

    Martyn Aldis Guest

    In message <[email protected]>,
    [email protected] writes
    >[email protected] wrote:
    >> I have clip on aero bars on my handlebar and I can't get the stem clamp
    >> on the handlebar tight enough to maintain the position of the
    >> handlebar. Normally, the handlebar stays in position but when I'm
    >> riding on the aero bars (which is the norm) and I hit a bump, I hear a
    >> little click noise and the handlebar rotates downward which puts my
    >> aero bar out of position (tilted down). I've tried re-positioning the
    >> handlebar and re-tightening as tight as I can but the handlebar
    >> continues to rotate when I hit a bump.
    >>
    >> So I'm forced to conclude that there is not enough friction between the
    >> stem clamp and the handlebar. I've considered that maybe I need to
    >> remove the stem clamp (it's threadless and easy to do) and sandpaper
    >> the clamp to roughen it. Or perhaps I could insert double-sided
    >> sandpaper to give some grip.
    >>
    >> Anybody else have this problem and any suggested solutions?
    >>
    >> Denis

    >
    >I've been able to increase friction between the stem clamp and
    >handlebar to reduce slipping. I used 80 grit emery cloth to rough up
    >the mating surfaces on both the stem and bar, sanding longitudinally
    >(though I don't know if that's important).
    >
    >Also, cleaning the mating surfaces with alcohol or acetone may help. It
    >certainly helps carbon seat posts stay put!
    >
    >Also, greasing the bolt (threads and shoulder) should help. Don't over
    >tighten.
    >
    >Good luck!
    >

    The paper shim (even one with grit on either side) is a bad idea as the
    paper fibres could fail dramatically. If you must shim, metal would be
    better.

    Are you sure the stem clamp is intended for the diameter bars you are
    using?

    Some modern stems and bars have sizes marked on them. Otherwise you can
    use callipers (digital or vernier) to measure them.

    The following web page has a link that will allow you to download the 3t
    manual in pdf form. The manual includes information on installation in
    general and recommended torque for the clamp bolts. (Page 43 of the
    English version).

    http://www.3ttt.com/ing/fr_manuale.htm


    --

    Martyn Aldis, e-mail [email protected]
    ==============================================================================
     
  4. > Are you sure the stem clamp is intended for the diameter bars you are
    > using?


    The stem clamp is the right size. It fits snug and I've been using the
    same stem, handlebar, and aero bars for several years. This is the
    first year I've had problems with the handlebar rotating on me.

    Denis
     
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