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Old 05-12-12, 10:46 AM   #1
K. Olsen
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Tightening headset bearings

I have an integrated headset and I think the top cap is not tightening enough. I have a carbon fork with carbon steer tube. I have a Ritchey topcap expander thing and I can't get it to pull the stem down tight with the bearings. I have a gap from the top of the stem to the top of the steer tube. Part of the problem is I have to tighten the plug before I put it in the tube otherwise I can't get the plug to stay still while I tighten...make sense? I could sure use some insight how to make this work
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Old 05-12-12, 11:30 AM   #2
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Most, if not all, expanding plugs separate the function of expanding and wedging in the fork from the adjustment of the top cap. Typically the top of the plug takes a fairly large hex key to expand and lock it, then the 6mm top cap screw is threaded into the locked plug.

If the headset isn't adjusting, the most common causes are,

1- fork too long, and top cap beaching on the top of the steerer.
2- stem not free to slide down, (forgot to loosen?) or some other obstruction
3- expander not tight and getting drawn up by top cap screw
4- centering cone missing from stack, or bottom of the stem resting on bearing top cover, rather than the cone. This is critical, as some cones sit very low above the headset and require a small OD spacer above to keep the stem from touching the bearing cover.
5- upper bearing inverted.

There are other possibilities, but this is for starters.

I suggest you, pull the top stack apart, down to the upper bearing, and reassemble it in sequence, making sure that you have a continuous, uninterrupted line from the lip of the top cap, down to the centering cone of the bearing, so that the cap can press the cone without anything getting in the way.

I suggest, you pull it
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Old 05-12-12, 12:40 PM   #3
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Originally Posted by FBinNY View Post
1- fork too long, and top cap beaching on the top of the steerer.
I've had cases in which I've had a gap, but it's been just a millimeter or so too short of a gap. You can easily test by adding a small spacer on top. If suddenly that fixes the problem, then your gap is not enough.
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Old 05-12-12, 03:38 PM   #4
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Good advice from the others.
Check again to make sure the stem is loose enough to slide down the steer tube.
The gap from the top of the stem to the top of the steer tube should be 1/8 inch.

Last edited by Al1943; 05-13-12 at 01:04 PM. Reason: TYPO
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Old 05-12-12, 03:42 PM   #5
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...
The gap from the top of the stem to the top of the steer tube should be 2/8 inch.
Is this a Typo? Most say 2-4mm which is about half that. I'd consider this to be near the upper limit of what's OK.
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Old 05-13-12, 01:05 PM   #6
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Is this a Typo? Most say 2-4mm which is about half that. I'd consider this to be near the upper limit of what's OK.
Yes, good catch, I meant 1/8 inch. Will correct.
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Old 05-13-12, 01:48 PM   #7
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Center line of the top stem pinch bolt needs to be below the top of the steerer tube,
on metal steerers that is usually fine,
carbon steerer I'd feel better if the steerer tube was proud above the stem
and a spacer above the stem, under the top cap, itself, being 6mm above
the end of the fork-steerer.
NB: You can get lovely carbon fiber tube spacers..

the top cap bolt should be greased so It wont unscrew
the whole expansion nut thing ,
when the headset preload adjustment is re done.

Last edited by fietsbob; 05-13-12 at 01:52 PM.
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Old 05-13-12, 07:14 PM   #8
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Ok, so I have plenty of clearance. I measure about 4.5mm from the top of the stem and the steerer. The problem I think is I can't put the plug in while it is still loose...when I try to tighten there is nothing holding it. I have to tighten the expander before I put it in so it can stay in place. Does this make sense? IF not I might just have to make a video because I have trouble explaining in words sometimes
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Old 05-13-12, 07:46 PM   #9
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Can you tighten the expander enough so it can hold itself in place and then tighten it up once you have it positioned? Then tighten the top cap with the stem loose to set preload.
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Old 05-13-12, 07:56 PM   #10
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take the plug apart and grease all the wedge bits. put some grit paste on the inside of the steerer. lock the plug in. adjust the headset as normal
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Old 05-13-12, 08:00 PM   #11
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Quote:
Originally Posted by K. Olsen View Post
...The problem I think is I can't put the plug in while it is still loose...when I try to tighten there is nothing holding it. I have to tighten the expander before I put it in so it can stay in place. ....
Pre-expand the plug so it's a snug fit into the fork, and push it down into place. That should provide enough friction on the expanding ring that you can tighten it. Sometimes the plug will be a bit undersized and hard to keep from spinning as you try to expand it. If so, try over -expanding slightly outside the fork, so you have to squeeze it down to slide it into the fork. Now it'll stay put as you tighten the expander.

BTW- these plugs depend on friction to stay put as you expand them. So be sure that the thread is well lubricated so thread friction will be lower and not tend to spin the entire unit.
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Last edited by FBinNY; 05-13-12 at 08:06 PM.
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Old 05-15-12, 08:48 PM   #12
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Well I tried the suggestions and still no work :-|
I went on ahead and ordered one that designed a little differently. Hoping it works out.
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