nut for the headset top cap



urge2kill

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I got a stem that came with a top cap, but there's no nut for the top cap. Shouldn't it come with the nut?
 

oldbobcat

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Aug 31, 2003
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Originally Posted by urge2kill
I got a stem that came with a top cap, but there's no nut for the top cap. Shouldn't it come with the nut?
No. The Allen-head bolt that holds the top cap down (and pre-loads the headset bearings) threads into a expanding nut inside the fork. That bolt comes with the headset.

You have the choice of using the cap that comes with the stem or the one that came with the headset. Select the one that fits better. There should be a small gap between the top of the steerer and the bottom of the nut. Also, the top of the upper bolt that clamps the stem to the steerer should be no higher than the top of the steerer. Use stem spacers to fine-tune.
 

urge2kill

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So I have to buy one of those "star fangled nuts"? My steerer is hollow and empty throughout.
 

urge2kill

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Does the headset come with upper and lower crown races, and upper and lower bearing cups?
 

dabac

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urge2kill said:
Does the headset come with upper and lower crown races, and upper and lower bearing cups?
A traditional headset should come with,(from the bottom): - crown race - bottom (ball) bearing assembly - bottom cup - top cup - top (ball) bearing assembly - top cone/race Threaded ones might have a washer, then a locknut. Threadless ones will have a conical compression ring. To threaded ones you can then add brake hangers, light holders and possibly some spacers. To threadless ones you can add pretty much whatever you want and think you need between headset and stem. Do note that for integrated headsets, things may be different. Cup and bearing can be one unit.
 

oldbobcat

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Originally Posted by urge2kill
So I have to buy one of those "star fangled nuts"? My steerer is hollow and empty throughout.
If the steerer tube is metal, yes, you need a star-fangled nut. If carbon, there are several types of internally expanding nuts. Setting the star nu requires a star nut setter. A badly set star nut will ensure that your bike will steer badly until you punch it through and install another. Don't try to do it without the tool. Your local shop shouldn't charge too much to do this for you.

All threadless headsets, whether integrated or not, have a crown race, a bottom bearing, a top bearing, a wedge shim (I can't remember the other names for this right now), a compression cone, a top cap, and a top cap bolt. A loose-ball bearing consists of cone (the crown race serves as the cone), balls, and a cup (inserts into the bottom of the head tube). On top, the cone inserts into the frame and the cup goes on top. The wedge shim keeps the top of the steerer centered in the bearing, and the cone, beneath the stem and spacers, compresses the bearings. On integrated headsets, shims are needed between the wedge shim and cone to provide some clearance between the cone and the frame. Some headsets have removable seals--follow manufacturer's instructions for proper installation.

When everything works properly, the top cap, stem, spacers, compression cone, and fork all rotate freely as a unit. Here's the link to the Park Tool headset page. http://www.parktool.com/blog/repair-help/categories/headset-service.
 

urge2kill

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Originally Posted by oldbobcat
If the steerer tube is metal, yes, you need a star-fangled nut. If carbon, there are several types of internally expanding nuts.
It's a carbon/aluminum fork with carbon blades and alloy steerer.

I need a 1 1/8" integrated headset. Is that the only spec? What about ID and OD?
 

oldbobcat

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Originally Posted by urge2kill

It's a carbon/aluminum fork with carbon blades and alloy steerer.

I need a 1 1/8" integrated headset. Is that the only spec? What about ID and OD?
Integrated or not. Integrated just means that the bearings are hidden inside the frame. Fitting and installing a headset is more complicated than your line of questioning here. Well, it can be very straightforward, but you can fall into some pretty deep holes, including destroying the frame if you do it wrong.

Probably the best thing to do is take your frame to a local shop, tell them you need a headset, and have them measure things up and let them order it for you. Or, if they have it in stock. Cutting the steerer (if necesssary), setting the star nut, setting the crown race, and pressing in the races (for non-integrated headsets) require specialized tools to do it right consistently. I've done it without the tools and made a mess, but I have to say I was lucky.

I don't know the inside diameter of a 1-1/8" steerer. Just tell the guy you need a star-fangled nut for a 1-1/8" steerer.
 

dabac

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oldbobcat said:
I don't know the inside diameter of a 1-1/8" steerer.
Don't know for CF ones, but for metal usually close enough to 1" for them to happily take an 1" quill stem/steerer tube extender/threaded-to-threadless adapter.
 

alfeng

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Jul 23, 2005
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Quote:Originally Posted by oldbobcat .All threadless headsets, whether integrated or not, have a crown race, a bottom bearing, a top bearing, a wedge shim (I can't remember the other names for this right now), a compression cone, a top cap, and a top cap bolt. A loose-ball bearing consists of cone (the crown race serves as the cone), balls, and a cup (inserts into the bottom of the head tube).


... CHRIS KING headsets do not have[COLOR=FF00AA]/[/COLOR]use a compression cone ... Quote:Originally Posted by oldbobcat .
[COLOR=FF00AA]Probably the best thing to do is take your frame to a local shop[/COLOR] ...


YES!
 

oldbobcat

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Originally Posted by alfeng
... CHRIS KING headsets do not have[COLOR=FF00AA]/[/COLOR]use a compression cone ...
So I've noticed. It appears that the top part of the top bearing is the bearing cone, and that serves as the compression cone, too. From bottom to top, the top bearing of a Chris King headset goes cup, balls, cone, the reverse of most loose-ball headsets.
 

urge2kill

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Originally Posted by oldbobcat
Cutting the steerer (if necesssary), setting the star nut, setting the crown race, and pressing in the races (for non-integrated headsets) require specialized tools to do it right consistently.
I found cheap versions of the tools, but do I really have to face the headtube? My headset instructions tell me to, but I don't have that tool.
 

oldbobcat

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Originally Posted by urge2kill

I found cheap versions of the tools, but do I really have to face the headtube? My headset instructions tell me to, but I don't have that tool.
It's impossible for me to answer that accurately without seeing the bike. Did the frame already have a headset, or is this a brand new build?
 

oldbobcat

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I feel like I'm playing 21 Questions. Aluminum frame? Did you buy it from Nashbar, by any chance?
 

alfeng

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oldbobcat said:
[COLOR=FF00AA]Probably the best thing to do is take your frame to a local shop[/COLOR] ...
Still true ... Particularly because the OP does not seem like a DIYer.
 

oldbobcat

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Originally Posted by alfeng


Still true ...
  • Particularly because the OP does not seem like a DIYer.
Yup. This has gone too long without knowing anything about the frame or the headset.
 

urge2kill

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Originally Posted by oldbobcat
I feel like I'm playing 21 Questions. Aluminum frame? Did you buy it from Nashbar, by any chance?
Brand new frame and fork
Aluminum
integrated
1-1/8"
performancebike.com

The shop told me "we don't do that", but one guy glanced and commented that it already looked like "a nice machined surface".


How do I know the top/bottom side of a crown race or bearing race? They headset fits nicely how it was packaged, but the bearing races have to be reversed to fit the headtube. The crown race, of course, doesn't mesh with the fork either way.
 

oldbobcat

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Originally Posted by urge2kill

Brand new frame and fork
Aluminum
integrated
1-1/8"
performancebike.com

The shop told me "we don't do that", but one guy glanced and commented that it already looked like "a nice machined surface".


How do I know the top/bottom side of a crown race or bearing race? They headset fits nicely how it was packaged, but the bearing races have to be reversed to fit the headtube. The crown race, of course, doesn't mesh with the fork either way.
Still doesn't tell me much.

On an integrated headset, the bearings should just drop into the frame. The crown race needs a crown race setting tool. The steerer and crown might also need some machining to get it to fit. Or it might simply be the wrong size. Anyhow, here's a link to the Park Tool page on headset technologies. http://www.parktool.com/blog/repair-help/headset-standards#is. You want to scroll down to "Integrated - Angular Contact System." Good luck.

I think you need to find a new bike shop.
 

urge2kill

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I just noticed that the frame came with a headset, but it doesn't seem to fit the headtube??? and the one I purchsaed separately is probably better anyway.