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Steeer tube not cut short enough

keithc440keithc440 Posts: 277
edited September 2018 in Workshop
I've just cut my steerer tube. Measured how much I wanted to take off and added 2 mm on so that the top cap would fit flush to the stem. Put it all together and there was play. I reckon I should have taken a few more mm off to take account of the top of the steerer bung. I've put a 5mm spacer on top and it's all tightened up nicely.
Question: Would trying to cut a few more mm off the steerer be too difficult or impractical ?
Question: Do you thing I would like get away with a smaller spacer on top, say 2mm(would look better) ?


  • timothywtimothyw Posts: 2,482
    If you have a guide for the cutter you might be able to get away with it.

    One thought though, so long as you set the preload with a 5mm spacer, once you have tightened the stem you could take off the top cap and replace the 5mm spacer with the 2mm one.
  • Thanks Tim. Good tip re preloading with a 5mm spacer first. I will get a 2mm and a 3mm spacer also and try it.
    I do have a cutting guide but feel to cut a few mm off could still be tricky.
    Thinking about what I did I took off 10mm of spacers form the top. I marked the steerer and measured that there was a tad over 4mm to take off. I added 2mm and took 6mm off. Thinking again I should have taken 10mm off.
    What I've done as it is now with 5mm spacer on top should be safe though shouldn't it ?
    It feels solid.
  • 5mm spacer on top should be fine. All my bikes are this way. It prevents accidental tightening of a top cap onto the steerer, which, if it’s carbon could be damaged.
    As long as the stem is supported inside by the expander, you’re good to go.
  • sungodsungod Posts: 15,256
    exact instructions vary between manufacturers of forks, unless they say otherwise the general approach to take with a cf steerer tube is...

    cut the steerer to ensure it remains long enough for the full depth of the stem's clamping area to be in contact with the steerer - with a secondary rule that you should not leave it so long that the bung will not extend the full length of the area that will be clamped

    [some manufacturers may say you actually need the steerer to extend a few mm above the stem]

    insert the bung, the amount these extend beyond the end of the steerer varies

    depending on the design of the various bits, you may find you can fit the top cap and apply preload without a spacer, but typically you'll need one

    fwiw i use a 2mm spacer
    my bike - faster than god's and twice as shiny
  • you don't need the 5mm spacer

    you don't need a 2mm spacer

    just trim the mm off and put everything together. MF has just trimmed a few mm off his steerer and it is simple.

    Alts, just file it off.


    Postby team47b » Sun Jun 28, 2015 11:53 am

    De Sisti wrote:
    This is one of the silliest threads I've come across. :lol:

    Recognition at last Matthew, well done!, a justified honour :D
    smithy21 wrote:

    He's right you know.
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