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Help, Star nut stripped!(16 posts)

Help, Star nut stripped!Len J
Nov 27, 2001 6:46 AM
Changed stems on my Trek OCLV this weekend. Unfortunatly, my (Old) Torque wrench decided to seize in the middle of tightening the adjusting bolt on the top cap, overtorquing the bolt and stripping the star nut. Now I have a star nut stuck in the fork that is unusable.

Anyone know of an easy fix?

Len
Serves you right!!cyclequip
Nov 27, 2001 6:54 AM
You shldn't be using a torque wrench anywhere near a bike. That top cap bolt is a light finger nip to take up slack on the bearings.
Now you gonna have to drill it out, or get a drift and push it deeper into the steerer tube so you can put in another one.
Thanks for the empathy!Len J
Nov 27, 2001 7:15 AM
Actually, under the heading of "Gotta know your own limitations", I (left to my own devices) tend to overtighten things which has caused me problems in the past. My solution to this was using a torque wrench. Up until this episode, It had served me well.

Thanks for the advice on fixing.

Len
He's right.vanzutas
Nov 27, 2001 7:16 AM
when I first read your post I was impressed that you actually used a torque wrench on your bike. Then I realized, the top of a threadless headset should be done by feel, and feel alone. Tight enough that it doesn't wobble and loose enough that it rotates.

The first thing that I would try is to just push it out through the bottom.
Huh?DCP
Nov 27, 2001 7:55 AM
Assuming you can find a torgue spec, wouldn't it always be better to use a torque wrench? Unless it breaks, of course. Speaking on behalf of ham fisted tool owners everywhere.
Sort of,TJeanloz
Nov 27, 2001 8:21 AM
Assuming you could find a torque spec, which would be impossible for this particular bolt. Without knowing the specifics of the headset, spacers, and anything else that could cause friction in the system, you could not recommend a torque spec. So yes, if there was a torque spec, it's better to use a torque wrench, but in this case, there can't be a torque spec (except perhaps a maximum- which you wouldn't want to approach).

In this case, the fix is to pound another star nut in above the old star nut.
Torque Recommendation...PsyDoc
Nov 27, 2001 7:40 AM
...for the top cap on a Reynolds Ouzo Pro is 22 inch pounds (or 1.83 foot pounds, 2.48 newton meters).
re: Help, Star nut stripped!Paul
Nov 27, 2001 8:47 AM
Len,
've I read that all you have to do is push the star nut deeper into the fork, shouldn't try to get it out though I dont know why you couldn't drill it out. I'm in the process of building a new kg 386, and just cut the carbon steerer last night, and they give a torque spec on the top cap. Supposely, everything that tightens on a bike has a torque spec. but I just use feel on the head cap. You did the right thing, too bad the experts who replied weren't a little kinder. In the past, i've just tighten to the point where there wasn't any play, and test the fork/bearings before every ride by appling the brakes and checking to see if the fork/headset moves. I'm sure you know this, but man, you must have really put some pressure on that cap to strip the nut.
Paul
The rest of the story....Len J
Nov 27, 2001 9:42 AM
is that I was "Bonding" with my son, as we worked on this project together. We were talking as I tightened the nut with the torque wrench, me "assuming" that I would hear the click when I reached the limit. Basically I wasn't paying attention and therefor didn't register that I had tightened it so dramatically (as a result of the faulty torque wrench). This definatly flls under "stupid wrench tricks"!

I've tightened this cap several times with no problem---until now.

Thanks

Len
The rest of the story....Paul
Nov 27, 2001 10:07 AM
Len,
For good info, go to parktool.com, read about problems with the torque wrenches that click/don't click. Hey, we all have those kind of stories. Let me know the outcome of the stripped nut.
Paul
Push it through w/ a dowel or leave it in, no big whoop. . .js5280
Nov 27, 2001 10:39 AM
Made a rookie headset mistake here just this past weekend on my new Superlight. Tried to tighten my headset w/out loosening the stem. In this case I had spacers above the stem because I wasn't ready to cut the steerer quite yet (experimenting w/ headset height). Course, it did nothing to tighten the fork agains the head tube cause I was only tightening tween the cap and the stem. It was a el cheapo plastic headset cap so I torqued out the center completely, D'oh! Fortunately it was $6 fix at the LBS and I got a styley aluminum one to replace the el cheapo plastic one. Very happy I didn't have to get a new head set. Course I over-torqued it by hand, at least you tried to do the right thing by using the torque wrench. Just a bummer it seized up on you.
Don't use a star nut with carbon steerer on yer' forks!CT1 Guy
Nov 27, 2001 11:53 AM
Just a quick message to say that using a star nut on a carbon fork steerer is not a good idea as it raises stress and can cause the steerer to fail - get an expanding plug insert instead - oh, and they come out as well!! If you haven't got calibrated wrists, then a torque wrench is a good idea, particularly to make sure you don't overtighten , particularly as carbon doesn't really like being crushed by over-zealous screw tightening.
Never say never,TJeanloz
Nov 27, 2001 1:13 PM
Time forks with carbon steerer tubes use a star nut. Somehow they try to convice you that it's "special"; but it looks, and works, just like a regular old star nut.
We're assuming...MikeC
Nov 27, 2001 12:59 PM
that you have a carbon steerer.
I'm embarrassed to say that I've done the same thing (with an alloy tube) and it was right before an event.
I actually got the nut turned sideways in the tube and pulled it out with needle-nose pliers.
And yes, I re-used it.
re: Help, Star nut stripped!metonymy3
Nov 27, 2001 4:46 PM
I use a threaded stem, and I'm curious about how a star nut works. I've seen a picture, and read Sheldon Brown's description, but I still don't get it. Can someone shed some light? Thanks.

Chris
re: Help, Star nut stripped!Crankist
Nov 27, 2001 7:50 PM
That darn thing is a thin, dished, moderately heat-treated cromoly steel nut which slides (with small effort)
into the steerer tube concave side up. It's outside diameter is scalloped; the contact points are sharp enough to lightly dig into the tube, function being to lock into place when pull-pressure is applied from above, as when pulling the tube up to fully contact headset bearings. Plus it serves as a topic discussion when nobody has air bubbles in their decals.
Mike