What nut is in this steerer please?

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stran11
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Joined: Tue Jul 31, 2012 2:10 am

by stran11

Hi All,

I have an older Look carbon fork (steerer is also carbon), I believe either HSC 1 or 2, that is too tall. I want to cut it down, but I am not familiar with the nut that is in place (please see photo). Can I simply hammer this nut down??

Thank you in advance,
Stanley
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themidge
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by themidge

It looks like some kind of expander mechanism, which it should be with a carbon steerer. If it isn't totally rusted tight, you should be able to unscrew the central bolt (often quite far down, and recessed) and it will loosen and come out.
If it's something else, I'm not sure what you should do, and it probably shouldn't be in a carbon steerer. There was a thread about a star fangled nut in a carbon steerer here not so long ago, might be useful.

Edit: found it

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Calnago
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by Calnago

Pretty sure it’s not the Cannondale type shown by @midge above. You need to unscrew the bolt (if you can), part way, then give it a little tap to try and loosen the other end that is pushing against the other side. If it’s loose then no problem. It should just drop out when you turn it over. Some penetrating oil may be required if things are really corroded.
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c60rider
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by c60rider

themidge wrote:
Wed Apr 25, 2018 10:00 pm
It looks like some kind of expander mechanism, which it should be with a carbon steerer. If it isn't totally rusted tight, you should be able to unscrew the central bolt (often quite far down, and recessed) and it will loosen and come out.
If it's something else, I'm not sure what you should do, and it probably shouldn't be in a carbon steerer. There was a thread about a star fangled nut in a carbon steerer here not so long ago, might be useful.

Edit: found it
I have an old Look KG261 with the hsc fork and carbon steerer tube and had exactly this problem a few months ago where the central nut was stuck inside the expander. From memory I think I ended up just knocking it straight down which separated the two so it all fell out and I bought a new one. The one I bought was this https://www.sjscycles.co.uk/headsets/1- ... -expander/ though I didn't get it from here but 1inch expanders are few and far between for carbon forks. As yours looks a bit rusty in there I'd spray plenty of lube in there to help loosen it and just tap around the edges of the central bit. Don't smack the expander as it's the central bit that's jamming it against the inside of the fork and you risk damaging the fork. If that doesn't start to free it up then smack it a bit harder! It's only really small perhaps a couple of cm's long so it won't take much bashing to loosen it off. :thumbup:

In hindsight with mine I think what happened was the central nut and expander were wedged together so it wouldn't unscrew and the expander was slightly turning inside the fork steerer. It wasn't loose enough to pull out in one so I just knocked it out as above.

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jekyll man
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by jekyll man

Have you tried it with the stem clamp undone?
It's more than possible the stem is compressing the steerer onto the bung enough for it to not release.
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Fiery
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by Fiery

A neat trick to pull out an expander plug that’s stuck even after it has been loosened is to ise the top cap and its bolt. Loosen the plug, loosen the stem bolts, install the top cap and bolt as you normally would and start tightening - instead of pushing the stem down, this will start pulling the plug out, and it will give you more leverage than just pulling it by hand.

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stran11
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Joined: Tue Jul 31, 2012 2:10 am

by stran11

Thank you all for your input!

Through more searching and asking, I believe it's part of an expander that is missing a piece. Will try lubrication followed by gentle hammering.

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