whats down my steerer tube

fat daddy
fat daddy Posts: 2,605
edited September 2016 in Workshop
I have a Specialised Roubaix SL - carbon forks and with at least 2 inches of spacers on it .... the stem was ridiculously high, I have been gradually lowering it to find the best position and I am now at a point where I have more spacers above the stem than below it

Now when I look into the steerer tube, I don't have a star nut .... or at least not one that look likes what is in my MTBs ..... it might be an expanding plug ?

what I need to know is does this plug thing provide a strength to the forks allowing me to clamp the stem on wuithout damaging the carbon ..... should I lower this plug as I lower the stem .... of which case I will need to cut the steerer tube down so the cap still screws down

Or can I just lower the stem indefinitely until the last mini spacer

Comments

  • sungod
    sungod Posts: 16,547
    edited September 2016
    if there steerer tube is cf then it'll be a plug/bung rather than a star nut

    typically this needs to be positioned so that the bung extends throughout the area clamped by the stem

    it varies a bit by manufacturer, if you look on their website you may find explicit instructions for your fork, this is just for example...

    https://media.specialized.com/support/0 ... 8_revE.pdf
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  • fat daddy
    fat daddy Posts: 2,605
    that is exactly what I wanted to hear .. thanks for the clarification .... I'll hold back dropping the stem any more until I can figure out if I need to lower the plug.

    Probably for the best anyway, there is so much steerer tube above the stem as it is, if I crash I will literally spear myself through my chest with the tube !
  • g00se
    g00se Posts: 2,221
    You can replace the bug with a longer one if necessary. Check the ones by Deda and Colnago.
  • fat daddy
    fat daddy Posts: 2,605
    will do ..... could be tempted to do that as eventhough I have THE longest steerer tube known to man, and we are talking epicly long ..... I am too scared to cut it !
  • mfin
    mfin Posts: 6,729
    fat daddy wrote:
    will do ..... could be tempted to do that as eventhough I have THE longest steerer tube known to man, and we are talking epicly long ..... I am too scared to cut it !

    If you're too scared to cut it get someone else to do it who has done it plenty of times.

    Last time I removed a bit from an already built bike it took 10 mins flat from grabbing the bike to having it all back together ready to ride, it really is that easy for someone who knows what they are doing.
  • sungod
    sungod Posts: 16,547
    fat daddy wrote:
    will do ..... could be tempted to do that as eventhough I have THE longest steerer tube known to man, and we are talking epicly long ..... I am too scared to cut it !

    measure, measure, measure, then once more for luck, cut

    often you'll need to use a thin spacer just above the stem to stop the cap bottoming out on the bung/steerer, 2 or 3mm is plenty

    fine tooth hacksaw blade, wrap the area to be cut with tape first to reduce likelihood of splintering, ideally use a guide to keep the cut straight

    use a bit of fine abrasive paper to smooth any sharp edges

    cf dust is not nice, do the cutting over a sheet of newspaper with some damp kitchen paper on it (helps stop the dust spreading) so you can roll it up afterwards for disposal
    my bike - faster than god's and twice as shiny
  • Wheelspinner
    Wheelspinner Posts: 6,562
    sungod wrote:
    fat daddy wrote:
    will do ..... could be tempted to do that as eventhough I have THE longest steerer tube known to man, and we are talking epicly long ..... I am too scared to cut it !

    measure, measure, measure, then once more for luck, cut

    often you'll need to use a thin spacer just above the stem to stop the cap bottoming out on the bung/steerer, 2 or 3mm is plenty

    fine tooth hacksaw blade, wrap the area to be cut with tape first to reduce likelihood of splintering, ideally use a guide to keep the cut straight

    use a bit of fine abrasive paper to smooth any sharp edges

    cf dust is not nice, do the cutting over a sheet of newspaper with some damp kitchen paper on it (helps stop the dust spreading) so you can roll it up afterwards for disposal
    Easy way to set a guide (if you don;t have the actual guide tool) is to use two headstems, with a spacer to protect them, set either side of the cut line. Just pinch the bolts up enough to keep them in place while you cut. So, stem, spacer - cut line - spacer, stem.
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