Should I get a spacer?
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Yes, In your case it won't put any preload on the bearings without the proper spacer on top. This video is a little long but explains how a threadless headset works.
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Yes, In your case it won't put any preload on the bearings without the proper spacer on top. This video is a little long but explains how a threadless headset works. How to adjust a threadless bicycle headset. (How it works and how to adjust it.) Aheadset - YouTube
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No, don't ride it. It will sort of function OK meaning it will steer and not fall apart but you could do some damage to the bearings/headset or worse in a short time. You mentioned removing a spacer which if it's the right thickness you could add it on top of the stem for a correct setup. Watch the video to understand it.
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You need a spacer so that the top cap can bear upon the spacer/stem combination in order to adjust the preload of the headset bearings. As it is, the topo cap is bearing on the steerer and not the stem/spacer, so the bearings cannot be correctly adjusted..
#6
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No, don't ride it. It will sort of function OK meaning it will steer and not fall apart but you could do some damage to the bearings/headset or worse in a short time. You mentioned removing a spacer which if it's the right thickness you could add it on top of the stem for a correct setup. Watch the video to understand it.
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I previously posted about it and was advised to take the spacer off - it's too tall. https://www.bikeforums.net/bicycle-m...-too-tall.html
In the current iteration, the steering tube extends above the stem and thus requires a spacer so that the top cap doesn't bottom out on the top of the steering tube.
Like this:
Another way to do it would be to put a thinner spacer under the stem, so that the bolt isn't above the steering tube, and there's a gap between the top of the stem (with no spacer above it) and the top of the steering tube., like this:
Last edited by Rolla; 06-25-21 at 08:20 PM.
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I'm confused. The top cap doesn't really do anything once the headset bearing is adjusted correctly and the stem locked in place. All I use the top cap for is to set the headset tension before torqueing down the top cap to lock it in. At that point all the cap is doing is preventing water and dirt from entering the top of the steering tube. One can remove it and ride normally.
In the OP's case one has to wonder if the headset is properly adjusted, especially since the picture of the cap seems to show the steerer tube is crooked.
Why are all of you knowledgeable guys saying there has to be a certain spacing on the top cap?
In the OP's case one has to wonder if the headset is properly adjusted, especially since the picture of the cap seems to show the steerer tube is crooked.
Why are all of you knowledgeable guys saying there has to be a certain spacing on the top cap?
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If you're confused watch the video in post #2 or one of the many videos and tutorials on threadless setup. It's very simple once you understand the function of the top cap preload, spacers and clamping the stem. OP says in another thread he was advised to remove a spacer from below his stem, OK, fine no problem except that if you remove a spacer from below the stem you have to move it to above the stem to maintain the proper spacing for the preload cap to work or cut the steerer tube (not the best solution in this case).
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I wouldn't make that diagnosis based on that photo, and even if the steerer tube was cut an an angle it will still function just fine as long as there's a gap between the top of the steerer and the top of the stem. The top cap doesn't interact with the steerer tube; it interacts with the top of the stem (or a spacer).
Last edited by Rolla; 06-26-21 at 09:16 AM.
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If you're confused watch the video in post #2 or one of the many videos and tutorials on threadless setup. It's very simple once you understand the function of the top cap preload, spacers and clamping the stem. OP says in another thread he was advised to remove a spacer from below his stem, OK, fine no problem except that if you remove a spacer from below the stem you have to move it to above the stem to maintain the proper spacing for the preload cap to work or cut the steerer tube (not the best solution in this case).
What confused me is why the spacers matter once the headset is properly adjusted. I think Rolla phrased the problem more clearly than I did, without the spacer/stem protruding above the fork tube it is hard to get the proper pretension.
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Thanks for the video but I've never had an issue adjusting a threadless headset.
What confused me is why the spacers matter once the headset is properly adjusted. I think Rolla phrased the problem more clearly than I did, without the spacer/stem protruding above the fork tube it is hard to get the proper pretension.
What confused me is why the spacers matter once the headset is properly adjusted. I think Rolla phrased the problem more clearly than I did, without the spacer/stem protruding above the fork tube it is hard to get the proper pretension.
*Yes, a lot of this is straight in line with the steer tube, which doesn't matter, but any off axis load coming in from the wheel or the handlebars tends to put a side load on the bearings, which through the tapered contact will result in an axial load trying to loosen them.
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I'm confused. The top cap doesn't really do anything once the headset bearing is adjusted correctly and the stem locked in place. All I use the top cap for is to set the headset tension before torqueing down the top cap to lock it in. At that point all the cap is doing is preventing water and dirt from entering the top of the steering tube. One can remove it and ride normally.
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When aheadsets first came out, the rule of thumb was to leave a 3mm gap at the top for the cap to seat into. Without the gap, the cap does not seat properly. Fast forward to today and crabon steerers that require compression caps at a certain location, the 3mm gap is no longer welcome so we add a 5mm spacer on a flush steerer for the cap to seat onto.
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