# quill stem tightening issue



## nayr497 (Nov 8, 2008)

I decided to raise my bars just a bit. Loosen the bolt in the top of the stem, tried to pull the bars up. Very hard to move, not seized, but tough. I pulled the stem out, which wasn't easy, and lubed the HT & stem. This bike is in very nice shape, not ridden in the rain at all.

Put the stem back in, pushed it down, went to snug the bolt and it went in a few turns, then just turned freely. Huh.

Pulled stem again, the expander cone (not the angular cut ones, just really a plug that has a bigger diameter on one side than the other, like an asymmetrical donut, sorry don't know the proper term for this part) was cocked at an angle. Put a flat head in the slot on the stem, pushed it out, pushed it back in so it was level.

Stem back in, tighten the top bolt down and it's now snug, but the bars turn. Not freely, but if you hold the wheel you can turn them.

Ideas?


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## nayr497 (Nov 8, 2008)

This is a Cinelli quill stem, circa ~ 1991.

I've moved it up/down before and never had any issues.

One thing I wondered about...which way should the wedge at the bottom be inserted into the bottom of the stem? Widest side into the stem? Narrow side into the stem? It is now wide side in, which seems correct, as it will then push the stem out and snug it against the HT inner wall. But, maybe I'm thinking about this all wrong.

I don't think anything is stripped since this was working just fine before I went to raise the bars and I didn't force or overtorque anything.

Hmm, I'm hoping I'm making a minor mistake and someone with more knowledge of quill stem mechanics will sort me out.

Thanks!


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## wim (Feb 28, 2005)

> _which way should the wedge at the bottom be inserted into the bottom of the stem?_


This way. If the cone has a ridge, line it up with the slot in the quill.

When loosening the stem again, you might have to use a wrench _and_ a (preferably plastic) hammer. Quite often, the cone remains tightly wedged in the quill even though you loosened the screw. In that case, back the screw out until it protrudes just a bit above the stem. Then tap the screw head with a hammer to dislodge the cone.


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## FBinNY (Jan 24, 2009)

If the cone ( actually a _frustrum_ or _tuncated cone_, but stick with cone) was at an angle, I suspect it or the bolt might be stripped. If you didn't force it and it simply didn't get far on the thread before jamming it's probably fine. If it's tight enough to ride now, leave well enough alone. Otherwise remove the stem, oil or grease the bolt threads, and clean and dry the outside of the cone and inside of the stem, leaving only a very light film of something like WD-40 or a similar light oil. 

Unless there's a small tab or key to engage the slot, the cone is kept from turning by friction alone, so it's important that there's more friction on the outer surface than in the thread.


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## nayr497 (Nov 8, 2008)

Very helpful tutorial, lads.

Okay...so the cone was in the wrong way. Ugh. (frustrum, ha I know what those are, should have known that). I bought this bike used, had never pulled the stem out.

Put the cone in the right way, put the stem back in, lubed everything...and the bolt threads in, but only a bit. I think I buggered the cone threads, maybe the bolt thread too.

Anything else to try with this setup? I can't hold the cone in any way to try and turn (force) the bolt to thread in. If I hold it with something, I think I'll chew up the outside.

I wonder if I can get just a cone? Are they universal? Proprietary to Cinelli stems?

Damn, don't know how the cone was originally put in upside down. That stinks. Hopefully I can replace the cone or the cone and bolt. Hopefully the stem is okay.

Thanks again though for the very thorough explanation.


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## wim (Feb 28, 2005)

If the bolt threads in only a bit and then hits strong resistance, the threads are probably buggered up. But if you can spin the bolt around without it going in any deeper, you might just be turning the cone. If so, take the entire stem back out. Before re-inserting it, pull the cone up into the stem with the bolt just enough for some friction to hold the cone in place and keep it from spinning. Then re-install the stem.

Not sure if another stem bolt / cone will fit your Cinelli, but chances are good it will. Some bike shops have a box full of old parts—that would be my first try if you need another bolt and / or cone. Your stem itself is almost certainly OK—this is a bolt 'n cone issue only.

If there's only slight thread damage, try holding the cone with vise grips and force the oiled bolt through in increments (turn in until strong resistance, turn back out, turn in until strong resistance, turn back out, and on and on until you've "restored the thread." Don't worry about scarring up the cone. Spreader cones are primitive, agriculturural technology where a few nicks and scratches don't matter.


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## FBinNY (Jan 24, 2009)

If the threads are only slightly buggered, Take it apart and hold the cone at the base with a decent pair of pliers and work the bolt back and forth until the thread runs smoothly. Make sure to work well past where it'll end up in the stem. Keep it well oiled and rest if it gets warm. With any luck at all, this is all you'll need to do. Since the cone never goes all the way in, a bit of nicking at the base won't hurt. Or you can clean it up with a file.

If you need to replace the cone, you'll probably need to visit a shop bringing the bolt with you. While the cones are similar the various brands use different threads, so you'll need to match it to your bolt.


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## nayr497 (Nov 8, 2008)

Wow, awesome help again!

I'll see how I go with this and get back to you! Very spot on advice, thanks so much.

I might have to send it to my old man; he's good with his hands, has all the tools, and is better at this stuff them I am. He likes conquering new stuff like this as well.

Thanks for the thorough instructions.


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## nayr497 (Nov 8, 2008)

Okay, sent off to the old man who has more tools than I do...

He's cleaned up the threads on the bolt. Goes into the cone a bit further. Two questions:

1) How far does the bolt need to thread into the cone to get the stem tight? (He has the bolt/cone and I have the stem/bike so can't just try it out)

2) He thinks it would be a good idea to try and clean up the threads on the cone. I'm guessing it is metric. Anyone have an idea on the TPI and bolt diameter? I know he can figure this out himself but thought I'd see if there is a standard for 1990 Cinelli quill stems. He might need to find a tap or see if the LBS has one. Mine didn't, maybe the one where he lives will.

Thanks.


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## FBinNY (Jan 24, 2009)

nayr497 said:


> Okay, sent off to the old man who has more tools than I do...
> 
> He's cleaned up the threads on the bolt. Goes into the cone a bit further. Two questions:
> 
> ...


1- it has to go far enough to spread the stem by a few thousandths of an inch. That's maybe 1-2 turns at the most from where it fist bottoms out unloaded. Assemble it out of the bike, and tighten until it bottoms, then test for another turn or two until you see the slot spread open.

2- don't know the thread offhand, and different makers use different threads, since it only has to match the wedge they provide, and not mate to anything else. I wouldn't bother trying to extend the thread except by using the wedge itself as a chaser and working it up by degrees. 

If you cannot thread it far enough consider winding one turn of duck tape onto the wedge, thereby enlarging it by enough to do the job within it's current range of travel.


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## wim (Feb 28, 2005)

nayr497 said:


> if there is a standard for 1990 Cinelli quill stems.


Cinelli 1A (left) expander bolt = M7 x 1
Cinelli XA (right) expander bolt = M8 x 1.25


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## nayr497 (Nov 8, 2008)

Wow...you two are GOOD!

Thanks for the information, I'll see how it goes. Hopefully this is the last time I need to gather knowledge from you two. Thanks!


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## nayr497 (Nov 8, 2008)

Just an update:

Sent bolt to my father, he cleaned up the threads and mailed it back. Took cone to my local mechanic and he put the proper tape through it, cleaned up those threads.

Bolt & cone back in stem, stem back in HT, bike ready to roll for a ride tonight.

Thanks for the info. and advice!


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