# cracked Star carbon steerer tube - help



## charliekeri (Apr 12, 2006)

A very bad thing happened. I attached a Cinelli graphis stem to my fork and when I clamped it to the steerer tube, the top of the Star fork steerer tube cracked. The crack goes down about a 1/2 inch and kind of cuts across. I know it probably isn't safe to ride although the stem clamp appears to be tight.

Is the steerer tube replaceable? Did I make an expensive mistake? Damn I barely screwed it down, the clamp was uneven.... I am scared of doing a Hincapie.


HELP


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## ballmon (Mar 23, 2005)

charliekeri said:


> A very bad thing happened. I attached a Cinelli graphis stem to my fork and when I clamped it to the steerer tube, the top of the Star fork steerer tube cracked. The crack goes down about a 1/2 inch and kind of cuts across. I know it probably isn't safe to ride although the stem clamp appears to be tight.
> 
> Is the steerer tube replaceable? Did I make an expensive mistake? Damn I barely screwed it down, the clamp was uneven.... I am scared of doing a Hincapie.
> 
> ...


Just how much preasure did you put on the stem bolts?? 50,000 PSI?? That tube has the thickest carbon layup of any I've ever seen outside of the Pinarello Onda carbon/kevlar fork. Tough stuff!! Did you use a torque wrench??


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## charliekeri (Apr 12, 2006)

*give me some credit*

Yeah I deserve all the jokes, but hey how about a little sympathy?.......No I didn't use a torque wrench, air gun, hammer, etc. The Cinelli Graphis stem's top clamp was uneven. I didn't realize it. Instead of both sides of the clamp coming together evenly, one side came in first (into the steerer). Since I had a spacer above the clamp (under the ahead cap) I couldn't the couple of millimeters it was off. 

Yeah I ^$%^%^ed - up. I'm beyond pissed. I'm just reaching out to find another sorry soul that has been through it to make me feel better. I posted it to give some other's out there a head's up, and you know what? I guarantee anyone who reads this will look a little closer next time they tighten their stem. 

Maybe finding someone who can reply and say "Hey my buddy did the same thing and has been riding the broken steerer tube for 3 years. It's strong." I know I got to replace it, but I was hoping to get through the season before dropping a load of cash.

I'm going to go back to sobbing and kicking myself in the ass now.................


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## ballmon (Mar 23, 2005)

Well, I do feel your pain. I've screwed some things up while building bikes, just not this. It's a totally spectacular gorilla move. I've cut one too short, which I guess puts me into the same BoneHead club you have now joined....LOL. Too bad that it will be such a pricey fix.


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## charliekeri (Apr 12, 2006)

I wish I could say I muscled it, but it didn't take much to snap it. I actually said "naaaah, that couldn't have been what I thought". I slept on it, then the next day decided to double check and take it apart. I have at least 20mm of spacers, so I'll either cut off the crack increase my flexibility or find someone with a shorter headtube that wants a 4 month old fork


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## ballmon (Mar 23, 2005)

charliekeri said:


> I wish I could say I muscled it, but it didn't take much to snap it. I actually said "naaaah, that couldn't have been what I thought". I slept on it, then the next day decided to double check and take it apart. I have at least 20mm of spacers, so I'll either cut off the crack increase my flexibility or find someone with a shorter headtube that wants a 4 month old fork




Whacking it off and going with as few spacers as you can stand is safer anyway. I've got an old Carbon Force fork if you need it.


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## charliekeri (Apr 12, 2006)

*much thanks*

Thank you very much for the offer. Very cool. I will let you know. I think I will cut off the bad. It appears to be less than a 1/2 inch. I will keep you posted. I just got new wheels so I don't want to lose any ride time.


-Charlie


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## ballmon (Mar 23, 2005)

charliekeri said:


> Thank you very much for the offer. Very cool. I will let you know. I think I will cut off the bad. It appears to be less than a 1/2 inch. I will keep you posted. I just got new wheels so I don't want to lose any ride time.
> 
> 
> -Charlie



1/2 inch!! Whack that puppy off and get areo! I got the impression that the crack was really long. The plug for the top cap (if properly installed) should support the inside of the tube from further compression when the stem is tightened. Good luck


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## charliekeri (Apr 12, 2006)

*update*

OK I'm a loser. Yeah I should be down lower, I know, I know. Most of the ride I am down anyway. I have been tweaking my position on the bike since I got it in April. This was just another stem I was checking out. 
Anyhow I just cut off a little over a half inch of dead steerer tube and removed all my "floyd landis hip necrosis spacers". All I have to say is the spacers did save my $$ ass. The crack was a "good" crack too, it went down about 3/8 an inch and then went horizontal. the rest of the tube down appears rock solid. As much as I should take the blame, the stem was pretty poorly designed - most likely designed for aluminum or just a bad batch. You should see how uneven the clamping bolt attachments are. And since it is all CNC'd and it is not a full wrap around clamp (it just clamped at the bolts) it made it like a sharp mini vice (if that makes any sense.) Funny thing is, this is the exact stem that they sell with the Colnago name on it.

thanks for holding my hand through this tough time in my life 

-Charlie


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## ballmon (Mar 23, 2005)

charliekeri said:


> OK I'm a loser. Yeah I should be down lower, I know, I know. Most of the ride I am down anyway. I have been tweaking my position on the bike since I got it in April. This was just another stem I was checking out.
> Anyhow I just cut off a little over a half inch of dead steerer tube and removed all my "floyd landis hip necrosis spacers". All I have to say is the spacers did save my $$ ass. The crack was a "good" crack too, it went down about 3/8 an inch and then went horizontal. the rest of the tube down appears rock solid. As much as I should take the blame, the stem was pretty poorly designed - most likely designed for aluminum or just a bad batch. You should see how uneven the clamping bolt attachments are. And since it is all CNC'd and it is not a full wrap around clamp (it just clamped at the bolts) it made it like a sharp mini vice (if that makes any sense.) Funny thing is, this is the exact stem that they sell with the Colnago name on it.
> 
> thanks for holding my hand through this tough time in my life
> ...


You might want to think about Deda Newton stem, it won't make a mess out of your steerer tube. They're virtually bullet proof, but watch the torque on the bolts when tightening.


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## charliekeri (Apr 12, 2006)

*much thanks*

Many thanks to all involved. All has been good, and I'm lower now - which is a good thing.


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## tmluk (Sep 19, 2005)

*Did you use the Fork Expander Plug?*

Did you use the fork expander plug that comes with the Star Fork? It is about 40-45mm in length which is about the full length of a stem's steerer tube clamp. It is heavy (45g) but it is much more solid than a tiny expander.

You can also use a stem with rise to compensate for your spacer loss. Glad you have a way out.


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## Al1943 (Jun 23, 2003)

I cracked the steerer tube on my Carbon Star (C-50). The stem is a Syntace with two binding bolts. I was using a torque wrench and the tube cracked at 9 nm, the recommended torque for the stem. I was being careful to tighten the bolts in small increments. I heard it pop but didn't realize it was cracked and rode it for more than a year with a 1 1/2 inch vertical crack. Finally gave in and ordered a replacement, $850 !!. Lessons learned.


Al


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## charliekeri (Apr 12, 2006)

*now I feel better*

Al,

I knew it wasn't just me. thanks for the reply. If anyone out there is listening be careful with seperate binder bolts that are "CNC'd or cut out". The can clamp unevenly and cut inward. I am now using a FSA K Force stem. It's pricey and sweet, but it is molded all around the steerer tube.

Sorry to hear you had to drop over 8 bills. I feel your pain.


Charlie


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## tmluk (Sep 19, 2005)

*Do a dry-run.*

I was very much worried when I installed the Newton-26 stem on my Star fork as well.
What I did was to use the cut-off (extra) steerer tube to do a practice run on the procedure. Therefore, if there is any problem, I would crack the cut-off section only. Did you use the expander supplied with the Star Fork.


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## charliekeri (Apr 12, 2006)

*I used the expander*

I did use the expander and to tell you the truth I think that is what saved the tube/stopped the crack. The expander was installed about 1/2" below the top of the tube. That is exactly where the cracked stopped and started to go horizontal. I cut the tube off a couple of millimeters below the horizontal crack. I played with the cracked cut off piece of tube with a pliers and the integrity of the carbon fiber below below the crack appeared strong. If I rode cobbles a lot I wouldn't be comfortable, then again I wouldn't be riding carbon fiber...........


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## idris icabod (Feb 7, 2005)

Charlie,

Texascyclesport has Star carbon forks on sale via their e-mail specials. I think they are selling for around $550. 

It might save you a little bit and make the mistake a little less painful.


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## Bocephus Jones II (Oct 7, 2004)

charliekeri said:


> Yeah I deserve all the jokes, but hey how about a little sympathy?.......No I didn't use a torque wrench, air gun, hammer, etc. The Cinelli Graphis stem's top clamp was uneven. I didn't realize it. Instead of both sides of the clamp coming together evenly, one side came in first (into the steerer). Since I had a spacer above the clamp (under the ahead cap) I couldn't the couple of millimeters it was off.
> 
> Yeah I ^$%^%^ed - up. I'm beyond pissed. I'm just reaching out to find another sorry soul that has been through it to make me feel better. I posted it to give some other's out there a head's up, and you know what? I guarantee anyone who reads this will look a little closer next time they tighten their stem.
> 
> ...


could be worse...Doug Sloan once cut a custom geo star fork too short so he never got to ride it at all.


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## odeum (May 9, 2005)

tighten the stem bolts sequentialy, that is, a little on top, then a lil' on the lower, aproaching the spec's torque gradualy to avoid this. a beam torque wrench works well for this, in comparison, somone using a "click" type torque wrench may tighten down the top all at once to full torque and this may result in a crack. that being said, i use no torque wrench on even stems w/ carbon, ti bolts, and have had no probs, as a feel for the adquate torque is developed over time if one has the tactile feedback goin'.

lots of shop mechs w/ experience do not use the torque wrench, though they may, in this day of fragile stuff w/ spec'd torque and liabilites state (with a wink) otherwise.

i have found the star steer tubes to be on the overbuilt side, able to handle adequate torque, practical for real-world road use and not susceptible to cracking upon building up. 





charliekeri said:


> Al,
> 
> I knew it wasn't just me. thanks for the reply. If anyone out there is listening be careful with seperate binder bolts that are "CNC'd or cut out". The can clamp unevenly and cut inward. I am now using a FSA K Force stem. It's pricey and sweet, but it is molded all around the steerer tube.
> 
> ...


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## elviento (Mar 24, 2002)

*Help is here.*

I am a fan of Colnagos but it does puzzles me that their steerers don't seem to be the sturdiest out there. Pinarello and Reynolds steerers seem much more solid. My colnago fork steerer had an uneven wall thickness and I remember seeing a thread on here where the steerer had some air bubbles inside the sidewall. When I cracked my steerer, I was using a Ritchey 4 Axis stem which has all sorts of carbon-friendly features. I really didn't tighten it that much, especially since it was probably the 2000th time I was installing a stem on a carbon steerer. 

So anyway, I got help from a gentleman who goes by the name "Bonked" on RBR, and I am happy to pass it on. 

Here is what you do:

Find a metal tubing (aluminum is best but copper and steel ok too), I would say 3"-4" is enough but there is no harm to go longer. It needs to have an outside diameter that's almost the same as but slightly smaller than (need some room for the epoxy) the inside diameter of your fork. It should be pretty close to 3/4". If you can't find a tube that's the right size, you will have to get a thicker one and have it machined down at a machine shop so that when you insert the tube down the steerer there should be a tiny amount of play. 

Then you can apply some epoxy and glue the tubing into the steerer. I cut some slots along the tube to give more room for the epoxy to sit (think gills on a shark's head). You could also drill some holes in the tube to achieve that. A thin layer of epoxy on the outside of the crack may help a little. Let it sit for a day and you can install a regular star nut. 

Total cost and weight penalty should be no more than 40-60g and under $50.


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## Bonked (Nov 11, 2002)

funny...i was just about to reply when i noticed elviento's response! his response just about covers it...if you want the full story, the original thread is at http://forums.roadbikereview.com/showthread.php?t=3203


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## Clevor (Sep 8, 2005)

elviento said:


> I am a fan of Colnagos but it does puzzles me that their steerers don't seem to be the sturdiest out there. Pinarello and Reynolds steerers seem much more solid. My colnago fork steerer had an uneven wall thickness and I remember seeing a thread on here where the steerer had some air bubbles inside the sidewall.


I just got my C50 and had forgotten about this thread. Glad it popped up again.

Heaven knows I'm a scrutinizer and can detect the faintest bit of lint stuck in the clearcoat, but I also notice the wall of the steerer tube on my Star Fork does not appear to have uniform wall thickness. It's also strange that for the weight of that fork, the steerer tube is not thicker.

I am a hotrodder and have assembled and blueprinted race motors. After awhile, you develop a feel for torque specs and can eyeball the 0.040" gap on piston rings without measuring. I mean, do famous chefs use a teaspoon or tablespoon or 1/4 cup to measure their liquids? :lol: 

Seriously, I don't use any of my many torque wrenches on stuff like the stem, when I'm using a carbon fiber steerer or bar. Sometimes the click-type torque wrenches seem to go overspec before clicking so the beam-type may be the best if you use one. I read in a bike mag somewhere that one pro recommended tightening enough so there is no movement, and tighten a bit more when you encounter it. I know I'm gonna follow this practice with that Star fork. It's too much trouble to me to epoxy that plug in there. Plus the expander plug that came with the fork already weighs a ton.


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## Bonked (Nov 11, 2002)

i've used my expander plug in my 'nago without any issues...i think if you use that, you're pretty much ensured that there won't be any issues.


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## divve (May 3, 2002)

If you're using a torque wrench start with 1/2 the recommended torque. Check whether stem is sufficiently tight. If not go up to 3/4 of the recommended torque. Usually 5-6Nm is sufficient to secure a stem.


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## manandjoe (Apr 14, 2006)

*Uneven wall thickness*

I am building up a cristallo as well and noticed that the star fork had an uneven wall thickness. Is that just the very top or does it get thicker the further down you go? I was comparing it to a fsa k force seat post that had an extremely thick wall, I know it for a different apllication.


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## Clevor (Sep 8, 2005)

I know roadies don't crash as much as mountain bike guys (and heaven forbid on a Colnago), but on my ATB bikes, nothing - bar, stem, shifters - are torqued to spec. After the usual endo where the bike will sometimes cartwheel end-on-end, you'd pick it up and the stem is canted 45 degrees to the right, the bar has torqued over, and the brake levers are pointing straight up. I simply twist them back into alignment. Better they give, than break.


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## manandjoe (Apr 14, 2006)

CharlieKer,

When you installed the stem did you leave a few mm from the top for a spacer? Did you try installing the headset cap prior to torking down the stem ? 

The key point being.... clamping down on the top of the steerer tube could have caused your failure.


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