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  1. #1
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    Headset spacer "gap" question

    On Park Tool's website, when adjusting a headset/spacer/stem assembly, it says to leave about a 3mm gap here:


    Now, I'm in the process of putting a different stem on my bike...But, it's taller where the stem bolts sit. So, with my existing spacers, that "gap" is quite a bit larger than 3mm. More along the lines of 6-8mm. The cap and screw still reach the star nut, but I'm a little concerned if that big of a gap is acceptable.

  2. #2
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    It's fine, don't worry about it. As long as the bolt reaches the star nut, you will be able to compress the headset bearings. If you are concerned about the stem being unsupported, try shuffling spacers from the bottom for smaller ones to bring the gap down to a smaller size.

  3. #3
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    Quote Originally Posted by wschruba View Post
    It's fine, don't worry about it. As long as the bolt reaches the star nut, you will be able to compress the headset bearings. If you are concerned about the stem being unsupported, try shuffling spacers from the bottom for smaller ones to bring the gap down to a smaller size.
    Just what I thought. Thanks!

  4. #4
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    Quote Originally Posted by wschruba View Post
    It's fine, don't worry about it. As long as the bolt reaches the star nut, you will be able to compress the headset bearings. If you are concerned about the stem being unsupported, try shuffling spacers from the bottom for smaller ones to bring the gap down to a smaller size.
    It's not really fine!
    The last part of your statement is true however- except shuffling (which would do nothing), removing an 1/8th" would do the trick.

    If your stem bolt is near or above the top of the steerer, remove spacers - If not a possibility, find a different headset with lower stack IMO
    Honestly... ahh I give up

  5. #5
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    I agree with highdell. At minimum I would want the top stem bolt no higher than the top of the steer tube.

  6. #6
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    Alright, I gotta go to the bike shop anyways since the new stem I have is oversized, so I'll snaggle a few smaller spacers then.

  7. #7
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    ^^ good call!
    Honestly... ahh I give up

  8. #8
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    Is the 6mm when the everything is setup and tight? Or before you have adjusted the headset?
    I wouldn't hesitate to go with 6mm - that's less than 1/4 inch.
    I'll bet most people wouldn't have even measured it - eyeball it and decide it's fine.

    Any more and I'd swap a spacer.

  9. #9
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    The general rule of thumb I've heard from stem manufactures is that the steer tube should be no lower than the centerline of the upper pinch bolt. If it's lower than this the stem won't clamp squarely and it compromises the system.

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    tagged.
    roccowt.
    rocnbikemeld

  11. #11
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    So, I bought some smaller headset spacers over the weekend that should give me enough wiggle room to get the bike properly tightened down.

    My follow up question is about handlebars. The current handlebars are steel, with a 25.4 clamping surface...The stem has a 31.8mm diameter. Now, the appropriate spacers at the LBS are $14, and I know you can get used, grey-market online, or cheap takeoff handlebars for right around $14. Are there any benefits to using a spacer system like that, or would I be better off just replacing the whole handlebar with something cheap?

  12. #12
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    Quote Originally Posted by bucksaw87 View Post
    Are there any benefits to using a spacer system like that, or would I be better off just replacing the whole handlebar with something cheap?
    You should be able to get a much lighter, aluminum bar in the 31.8 diameter. New take-offs or old stock can be had for good prices.

    There are supposed benefits to going with the OS (oversized) 31.8 diameter, but in the real world, the main benefit is for the manufacturers (same size for road & mtn stems + a new "standard" to sell more stuff (cynical me)).
    [SIZE=1][/SIZE]

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    My policy is not to mess with shims on parts that are keeping me on the bike. Especially not shims that big.

    A pair of used bars will likely be cheaper and safer,

  14. #14
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    Cool! Now, to scrounge around bike shops for a bit to find some cool takeoff bars.

    I know it ain't much, but the old stem and bars were steel...The new stem is aluminum, so we'll see if we can find an aluminum bar to lighten things up a few more grams.

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