I have just adjusted my spacers positions on my headset. There origionally 3 spacers below the stem one larger than the others and none above the stem, then I took the 2 smaller ones and placed them above the stem, will this affect the gap between the steerer tube and the top cap, (even if that matters). As I am unsure because I was thinking as long as I have the same amount of spacers on the steerer tube then it doesn't matter, or is there importance to do with the position of the stem?

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  • Also, I felt no play in the headset when tightened.
    – Asher
    Apr 8, 2021 at 12:23
  • 1
    Make sure you adjust the bearing preload correctly. There should be no play but it should also turn with very little force/friction. Use a torque wrench for clamping the stem, especially if you have carbon parts.
    – Michael
    Apr 8, 2021 at 20:28

2 Answers 2


You are fine and your understanding is correct. It's the total stack height of the spacers and the stem between the top of the headset and the cap that matters, so spacers can be swapped from below the stem to above and vice versa to adjust your stem height as you like it.


You can have all the spacers you want above the stem on a steel or aluminum steerer.

On carbon, some manufacturers use a wall thickness where their specified compression plug acts as a reinforcement for the clamped area. In most cases this will apply to the kind of plug where the part you turn down consists of thick aluminum that contacts the steerer ID all around. And because it's only so tall, that means you could be lacking sufficient reinforcement if there's too much spacer on top. I wish this wasn't true, but it is. In practice, one 5 or even 10mm spacer would likely never be a problem. But it's a good boundary to leave unpushed.

  • 1
    To clarify, you're saying that some carbon steerer tubes require a reinforcement inside the section clamped by the stem in order to prevent crushing of the steerer tube there. In that case, the fork manufacturer specifies a compatible compression plug and one needs to be sure that the "plug" part is actually in the section that the stem is clamping, not moved up too high by having lots of spacers on top, right?
    – Armand
    Apr 8, 2021 at 23:43
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    @Armand Yes exactly. The higher end Cannondale road bikes all have this going on, or have at periods in time, to name one example. Apr 9, 2021 at 0:43
  • Surely a few extra layers of carbon is both lighter and stiffer than a beefy expansion plug?
    – MaplePanda
    Apr 9, 2021 at 7:01
  • I am still a little confused, but I am guessing this is fine then, my fork is carbon, do I need this compression plug you guys are talking about?
    – Asher
    Apr 9, 2021 at 8:17
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    @MaplePanda Who knows. The sort of plugs I've seen this apply to are the "inverse" shaped ones like the Cannondale Si. I think it's probably reasonable enough as a way of shaving grams for a pro level bike. Putting the same system on a mass market bike is the unreasonable part. Apr 9, 2021 at 11:40

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