Dropping stem height

bobgfish Posts: 545
edited February 2014 in Workshop

I have a full carbon fork and want to remove some of the spaces underneath it. Maybe up to 25mm. I know it's a simple job but inside the fork is a bung (not sure the exact name) which I guess gives support so that you can't clamp the stem up to hard. Does this also need moved down? Or leave as is? I plan to ride like this for a few weeks until I decide if I like or not before getting steerer chopped. I assume it will be safe just to move spacers without any worry.



  • slowbike
    slowbike Posts: 8,498
    Move the spacers from underneath to on top
  • on-yer-bike
    on-yer-bike Posts: 2,974
    In theory you are correct that the bung may not reach the clamping area. Many people ride their bikes with a few spacers on top, including me, for the same reason. It also makes the bike easier to sell if there is some room for adjustment. Just use carbon paste and do not over tighten the stem, I only use 4 Nm on my stems.
  • imposter2.0
    imposter2.0 Posts: 12,028
    The distance between the bolt in the top cap and the fork bung does not change by any more than a few mm, depending on the width of the spacers being used..
  • keef66
    keef66 Posts: 13,123
    Well the bung in the carbon steerer on my Scott sits just proud of the top of the steerer tube. Scott are insistent that you have a max of 5mm spacer above the stem, presumably so that the stem is clamped onto the part of the steerer which is supported internally by the bung.

    If you on the other hand have the kind of bung which you can move further down into the steerer then you have the option of leaving the steerer uncut and simply moving the spacers from beneath the stem to above it. Obviously it would be prudent to move the bung down the steerer so that it supports the new clamping zone.

    If instead you're planning to lose the spacers and therefore need to cut the steerer, remember to remove the bung first!