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Old 02-16-08, 10:25 PM   #1
purevl
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Star Nut Trouble

I'm working on my On-One Inbred and when loosening the top cap the "star nut" (in this case it is actually just a disc) is rotating inside the top tube. I take it that this is not the way it is meant to function. So i assume that i'll be replacing it very soon. My question is this: how can i keep it from rotating to get it out? I thought about tapping the whole thing up and out, since it is obviously loose, but in reading Sheldon it seems as if this might damage the head tube. Any suggestions?

Also, are there any reasonably reliable "homebrew" methods for installing a new star nut? I'd prefer not to buy a tool i will in all likelihood use only once, but since it's relatively cheap i suppose i can if there's not a good free/cheap method. This is the second new-to-me technology that has failed miserably today. First the self-extracting crank bolt completely stripped the extraction threads, and now the damn star nut won't do its job. Not to sound too retro-grouchy but at the moment i am really not seeing the value of these improvements.
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Old 02-16-08, 10:34 PM   #2
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Did the "teeth" of the star nut dig a groove into the steerer? You might be able to just tap the star nut down farther into the steerer tube a few MM. It should then have a better "bite", and hopefully won't spin anymore.

As for installation...I've put a few in with no special tools...but they all were going into steet steerers. AL ones might be harder, since the tube walls are thicker...?
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Old 02-16-08, 10:38 PM   #3
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The steerer is steel. What i'm saying is that i can't actually get the top cap off because when i try to loosen the bolt the nut turns with it. As far as i can see from the bottom, there are no teeth, it just looks like a flat disc with a lip on it. Like a small upside down tin. Do you think if i tap it up it will bite? or would this damage the steerer?
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Old 02-16-08, 10:43 PM   #4
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By top tube I take it you mean steerer tube. By star nut I take it you mean something that takes the place of a star nut, a compression washer of some sort. Could you supply the brand and model of headset? Type and material of fork and steerer tube?

Personally, if it's steel or aluminum, I'd tap it out from the bottom with a dowel. A new star nut should install no problem, even if the inside of the steerer tube is scarred.

A star nut tool is handy, but not essential. You can use the compression bolt (or a longer one with the same thread) to drive it in. Work it in slow, correcting it if it starts getting crooked, and make sure not to drive it in too far where the bolt threads won't reach. The tool sets it at the right depth and has the leverage to straighten it if crooked, but that's all it does. Our shop charges the minimum $5 for the service.
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Old 02-16-08, 10:48 PM   #5
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Can you put enough pressure from the bottom with a screwdriver to hold the disc while you turn the allen bolt?
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Old 02-16-08, 11:05 PM   #6
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Originally Posted by Wordbiker
By top tube I take it you mean steerer tube. By star nut I take it you mean something that takes the place of a star nut, a compression washer of some sort. Could you supply the brand and model of headset? Type and material of fork and steerer tube?
I did mean steerer tube, my frustration is affecting my command of the language.

Sorry for that, I was under the impression that compression washers are generally used in carbon steerer tubes, but like i said it is my first threadless experience.

The steerer/fork is reynolds 853 steel, and the headset is an FSA "The Pig"

Given that would you tap it up with a dowel?

I'm so annoyed with it right now because i was really really excited about this bike but nothing seems to be going my way. On an older bike i'd be riding it already for the cost of two-hours work and some grease. Now it looks like i'll be replacing: the bottom bracket and wheel bearings, because naturally they aren't rebuildable and feel rough as hell, a star nut/compression washer that won't stop rotating, and most expensively a stripped crank arm that i may or may not even be able to remove. Things are getting very expensive very fast.
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Old 02-16-08, 11:12 PM   #7
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Quote:
Originally Posted by purevl View Post
I'm working on my On-One Inbred and when loosening the top cap the "star nut" (in this case it is actually just a disc) is rotating inside the top tube. I take it that this is not the way it is meant to function. So i assume that i'll be replacing it very soon. My question is this: how can i keep it from rotating to get it out? I thought about tapping the whole thing up and out, since it is obviously loose, but in reading Sheldon it seems as if this might damage the head tube. Any suggestions?

Also, are there any reasonably reliable "homebrew" methods for installing a new star nut? I'd prefer not to buy a tool i will in all likelihood use only once, but since it's relatively cheap i suppose i can if there's not a good free/cheap method. This is the second new-to-me technology that has failed miserably today. First the self-extracting crank bolt completely stripped the extraction threads, and now the damn star nut won't do its job. Not to sound too retro-grouchy but at the moment i am really not seeing the value of these improvements.

I bet I know what you got by what you say, (Funky aluminum expansion plug,,,,)I have seen it, in truth I forget how I got it apart, I did end up very carefully driving it out the top. And then I vowed not to buy another one like it, I replaced it with an FSA Headset, no more problems. Not star nut.
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Old 02-16-08, 11:18 PM   #8
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Given that would you tap it up with a dowel?
I would. Any of the compression washers that take the place of a star nut that I have seen shouldn't damage a steel steerer if driven up with a dowel. Most likely it's just a bit of corrosion making it stick, and is easily broken loose with a tap. If it were a star nut designed to be driven only one direction, yes...it could cause some damage, but it's still more likely to be destroyed than to damage a steel steerer.

BTW, I didn't mean to mock your terminology, just meant to clarify so we'd be talking the same language.

I am sorry about the troubles. Had you posted about the self-extractor, I could've warned you that they also often seize and do not allow for crank removal without being removed and a standard crank extraction tool used. They're much like titanium crank bolts in that it's best to torque with a steel bolt, then install the ti bolt.
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Old 02-16-08, 11:43 PM   #9
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I would. Any of the compression washers that take the place of a star nut that I have seen shouldn't damage a steel steerer if driven up with a dowel. Most likely it's just a bit of corrosion making it stick, and is easily broken loose with a tap. If it were a star nut designed to be driven only one direction, yes...it could cause some damage, but it's still more likely to be destroyed than to damage a steel steerer.

BTW, I didn't mean to mock your terminology, just meant to clarify so we'd be talking the same language.

I am sorry about the troubles. Had you posted about the self-extractor, I could've warned you that they also often seize and do not allow for crank removal without being removed and a standard crank extraction tool used. They're much like titanium crank bolts in that it's best to torque with a steel bolt, then install the ti bolt.

Thanks, i will give that a try in the morning, for now i shall go and pour some libations to the gods of bikedom and hopefully assuage their apparent anger with me.

I didn't take it to be a mockery at all. I may not post here often but i do lurk in the mechanics forum quite a bit and i "know" you to be a generally helpful guy, I appreciate the correction.

As for the self-extracting bolts... Sometimes i have to learn things the hard way. Any idea where i might find an older model Truvativ Stylo SS crank for cheap?

Thanks for the help everyone, hopefully i'll get this all sorted soon.
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Old 02-17-08, 07:22 AM   #10
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Dur...for some reason it didn't register in my head that your top cap would most likely still be on...

That model headset usually comes with a standard star nut, strange that they'd put an expander plug in...

Try just applying pressure from underneath first, as someone already posted...hopefully that will work, and you won't have to tap it out.

Let us know how it goes!
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Old 02-17-08, 07:05 PM   #11
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Popped right out with a dowel rod and a mallet, nothing serious to the steerer, maybe a few scratches.
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Old 02-17-08, 07:32 PM   #12
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Popped right out with a dowel rod and a mallet, nothing serious to the steerer, maybe a few scratches.
Glad Phase one went well for you.

I hope Phase Two (installing the new star nut...unless you plan to reuse the compression stack...) goes as easily.
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Old 02-17-08, 07:34 PM   #13
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So it did end up being the compression/expander deal?
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Old 02-17-08, 07:41 PM   #14
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Yes, it was in fact the compression stack. At the moment i have yet to get the screw free from the expander wedge. What would you recommend? Theres a star nut on the way but if i lubricated the threads on the screw and was sure to clean the contact surfaces of the expander and the steerer tube would there be a problem re-using it? I think it failed due to a combination of the threads oxidizing together and a lack of friction between the compression stack and the steerer tube. (grease?) what's the recommended surface treatment between the two?
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Old 02-17-08, 09:43 PM   #15
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That is the main issue with those expansion plug setups: the internal friction often overcomes the desired friction inside the steerer tube before it has a chance to wedge and compress the headset.

I have had some success with using grease on the threads and internals, then coating the outside surface with anti-seize compound. Make sure to coat the wedging surfaces so they slide. This may be something to try before installing that star nut. If it works, there's nothing wrong with the compression plug system.
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