# cracked steerer



## Bonked (Nov 11, 2002)

while trying to setup the headset/stem on my new used fondriest yesterday (click <a href="http://forums.roadbikereview.com/showthread.php?t=3174">here</a> for yesterday's issues with the headset), i heard a ripping sound while installing the stem. i pulled everything apart this morning and there is a crack in the steerer on the fork, which is a mizuno mc full with a carbon steerer. the crack is shown in the pic where the arrow is; the white line above the one with the arrow doesn't seem to be a crack but a little crease. when i was installing the stem, i was using a torque wrench and tighening to the stem (newton) guideline of 8Nm and tightened the lower bolt to around 5Nm, then the upper bolt to 5Nm, then each bolt again up to 8Nm. i have a few questions about this and would greatly appreciate any feedback:

1) did i do something wrong? i have repeatedly installed the stem on my other bike with a carbon steerer without any issues and had previously installed the stem on this fork just fine.
2) does this fork have a max torque of less than 8Nm?
3) yesterday's issue was that i couldn't get the play out of the headset and tightened the top cap much more than i was comfortable with. would stressing the carbon steerer by compressing it with the top cap make it more prone to crack when you install the stem?

and here is the one i know the answer to, but have to ask anyway:

4) is there anything i can do to fix this so i can ride this fork?

thanks!


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## Rusty Coggs (Jan 28, 2004)

*Buggered fork*



Bonked said:


> 3) yesterday's issue was that i couldn't get the play out of the headset and tightened the top cap much more than i was comfortable with. would stressing the carbon steerer by compressing it with the top cap make it more prone to crack when you install the stem?
> 
> and here is the one i know the answer to, but have to ask anyway:
> 
> ...


No message


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## MR_GRUMPY (Aug 21, 2002)

*I'm cheap enough to try epoxy.*

The crack seems kinda' low on the stearer. Maybe I'm looking at it wrong, but it looks like the crack is below where the stem and expander plug go. You are using an expander plug, aren't you ?? What kind of stem are you using ? Some stems aren't the best for carbon stearers.


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## KATZRKOL (Mar 4, 2004)

*Mr. Grump's Right. .Really Low*

It is absolutely essential you have the expansion wedge inside the fork tube before tightening the pince bolts on the stem. The expansion wedge does two things: it allows you to (when tightening the top-cap) pre-load the bearings, and it provides a circumferential support for the wall of the tubing when locking down the pinch bolts. 

That said, that crack seem to be nowhere near where I'd expect to see an "over tensioning" of the bolts. Yes, some stems are better than others. The Richey WCS was the first stem (that I've seen) that has a bias cut. . Excellent idea. One thing carbon fiber does NOT DEAL WITH: POINT LOADING!

You can't "fix" carbon fiber if cracked, and a steerer tube is no place to screw around. Hopefully, you can get a replacement under "crash replacement?"


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## C-40 (Feb 4, 2004)

*you goofed..*

Looks to me like you had a bunch of spacer on TOP of the steering tube, resulting in the stem being positioned BELOW the expanding plug, so it did not reinforce the steering tube properly. On top of that, you probably cranked down way too hard on the stem clamp bolts.

Those who advocate using a lot of spacers and putting the extra on top of the stem seem to forget the location and purpose of the expanding plug may be compromised during this trial fitting period.

You might be able to salvage the fork, but the only half-way safe method would be to stuff a cork in the steerer, at least an inch below the crack and fill the whole inside with epoxy.

Of course, you should get your bar height figured out first.

I measure my bar height vertically from the floor to the top of the bars. I know exactly how high is "high enough", so I have no more than 5mm of possible adjustment. Although bottom bracket height has an effect on bar height, there are few frames that deviate much from the nearly-standard 7cm BB drop, so it's rarely a concern.


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## buffedupboy (Feb 6, 2003)

*Yup, you goofed*

You had your expander bolt (I pray you didn't use a star nut), too tight, and you clamped down just below or at the bottom of the expander bolt. The torque you applied was enough to crush the steerer tube past the expander bolt thus causing the tube to deform past the expander bolt and cracking.

I would guess that if you cut the steerer tube down and have your expander bolt reinforcing the tube behind the crack, you would be fine.... but if you crash.... don't come blaming me.... Me being a cheapass would give it a shot. You should also be checking that you had the right angle bearings on your headset in the first place.

Regards,
Sean


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## Dave_Stohler (Jan 22, 2004)

It's still probably safer that the fork that idiot modified in my post yesterday.....


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## Bonked (Nov 11, 2002)

yeah, looks like i screwed up! i was trying to dial in my position before i cut the steerer and think that the expansion bolt wasn't down far enough. oh well, it's not really spring until you break a critical and expensive part of the new bike you've been working on all winter and taken for only one ride, right? i am going to try calling fondriest, although i don't really expect to get anything from this. anyone know anything about mizuno forks...they don't seem to be very easy to come by and i don't know if you can by the equivalent of the fondriest mc full except through fondriest.

also, the expander that came with the fork is not that long and i would like to replace it with one like the one that came with my colnago...it's about an inch and a half long. does anyone know where to get an expander like this? i know i have seen them before but now can't find it.

thanks for all of your responses!


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## Bonked (Nov 11, 2002)

ps - i'm using a newton. i have never heard that there are "good" and "bad" stems to use with carbon steerers...is this a "good" one?


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## divve (May 3, 2002)

Fondriest does sell their forks separately. If I'm not mistaken the MC Full lists for around $450...not a cheap fork.

The expander you're talking about is very similar or perhaps even identical to the one by ITM. Anyone dealing with QBP should be able to get it. If that fails I've seen it at a UK online shop:
http://www.wiggle.co.uk/v2_product_detail.asp?ProdID=5360010872

Your stem should be fine. Personally I go by feel when tightening bolts. I really don't like the idea of a torque wrench on delicate parts, unless you know exactly how to use one (there's more to it than most people expect) and that it's calibrated properly.


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## Dave_Stohler (Jan 22, 2004)

With any luck, you only damaged the part that you're now going to cut off, anyways. If the damage is just up at the very top, right by where you cut the end anyways, you should be OK.


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## Bonked (Nov 11, 2002)

no, it's right at the bottom stem bolt and i unfortunately had the stem pretty close to where i want it!


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## Bonked (Nov 11, 2002)

$450...that's what i was afraid of! do you know if they sell the same fork under a different name for less...i.e. it won't be a "fondriest mc full" but it would be the same thing without the stickers for less?

also, that itm expander is exactly what i am talking about. i'm pretty sure i have seen one mail order in the us but, of course, can't find the site now. i'll try my lbs.

thanks!


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## divve (May 3, 2002)

From what I read it's their exclusive design and manufactured by Mizuno.


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## C-40 (Feb 4, 2004)

*fork sources...*



Bonked said:


> $450...that's what i was afraid of! do you know if they sell the same fork under a different name for less...i.e. it won't be a "fondriest mc full" but it would be the same thing without the stickers for less?
> 
> also, that itm expander is exactly what i am talking about. i'm pretty sure i have seen one mail order in the us but, of course, can't find the site now. i'll try my lbs.
> 
> thanks!


http://www.bicyclebuys.com/HTML/Shocks_Forks.htm

Do a ggogle search under mizuno forks. There should be many possible sources. You don't need to buy a Mizuno either. Any 1-1/8" fork of the same length (I think they are 374mm) will do. If I was buying a new fork for my Fondriest, I'd get one with only 43 or 40mm of rake to slow the steering a bit. Fondriests are pretty quick steering.


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## bburgbiker (Apr 7, 2003)

*sorry to hear about your mishap but...*

you could cut the steerer just below the crack and then attempt to sell it through the classifieds or ebay. what size is your frame? if it's a larger size you might have some room to cut and someone with a smaller frame might be interested. hope you're able to work something out.


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## Bonked (Nov 11, 2002)

yeah, i figured that i'll probably do that. i think i won't cut it, but advertise it with the distance between the headset race and the crack shown. fortunately, i ride a larger bike, so there is some room. unfortunately, i don't use a lot of spacers so there isn't that much. it does suck that it is a perfect fork except for that one small crack!


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## buffedupboy (Feb 6, 2003)

*being the cheapass that I am.*

I would install the fork properly with the steerer cut. I will also mark the location of that crack. You could be lucky in that only the top layer is cracked.... who knows. I would then ride the bike a few times and see what happens. Pull it off and check whether the crack has increased.... but like I said, I can't stand waste, I am cheap and if my views defer to yours, don't follow it.... and most importantly..... may god be with you.....I mean force...

Ciao,
Sean


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## Bonked (Nov 11, 2002)

no, you can feel the crack on the inside...so it goes all the way through. called fondriest and their warranties don't transfer unless you get an extended warranty at the time of the sale; they also don't have any more 2003 forks and the cheapest 2004 fork retails for $499...ouch! (i must say, however, that they did offer to send me a used, cut fork for the price of shipping, but they didn't have any with enough length left for me...customer service from fondriest ROCKS.) i think i will try shoring it up with the expander right behind the crack and filling the steerer with epoxy...don't have much to loose at this point. i'll mark the ends of the crack, gingerly take it out for a few rides, then see if it has gotten any worse. if not, i'll gradually ramp up the harshness of the rides and keep an eye on it.

by the way...what kind of "epoxy" would you use? i'm not much of a do-it-yourselfer, except for my bike (unfortunately!), so could use some help here.

thanks for all of your help!


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## RUSA2392 (Feb 5, 2004)

*How about a new stem and cutting the steerer lower ...*

Could you get below the crack if you cut the tube and used an upward sloping stem mounted without spacers? Might not be a stem police beauty, but maybe that's preferable to a $500 lesson or the risk of keeping the crack....


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## divve (May 3, 2002)

I'd rather trade-in the fork for an Easton instead of risking extensive dental and skull repair. Their offer is still valid until April 1.

http://www.veltecsports.com/forkitover1/welcome.htm


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## C-40 (Feb 4, 2004)

*epoxy fix...*

If you try to repair with epoxy, you should clean the inside of the steerer with acetone first, then sand the inside with 120 grit sandpaper to insure a good bond. Just get the standard drying time (not 5-minute) epoxy glue.

The difficulty in making this type of repair will come from the Mizuno expanding plug and top cap. Since the top cap has a long internally threaded sleeve that fits fairly tight inside the steerer, any epoxy in this area will foul up the fit of the top cap. You would have to be carefully to apply the glue only below the area where the top cap extends.

A different style of expanding plug would be better. Colnago's would be great, but getting one might be tough. Try contacting the importer at www.trialtir-usa.com.

The suggestion to remove all spacers and use a different stem angle should be considered, depending on the current stem angle and amount of spacer. An 84 degree stem, flipped to 96 degrees is 2cm higher than it is in the 84 degree position.


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## RUSA2392 (Feb 5, 2004)

*Thank you C-40*



C-40 said:


> If you try to repair with epoxy, you should clean the inside of the steerer with acetone first, then sand the inside with 120 grit sandpaper to insure a good bond. Just get the standard drying time (not 5-minute) epoxy glue.
> 
> The difficulty in making this type of repair will come from the Mizuno expanding plug and top cap. Since the top cap has a long internally threaded sleeve that fits fairly tight inside the steerer, any epoxy in this area will foul up the fit of the top cap. You would have to be carefully to apply the glue only below the area where the top cap extends.
> 
> ...



You are the God of bike fit and you endorsed my suggestion. 

I can't tell you how flattered I am. i only wish it made me faster or go farther!!!


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## mtpisgah (Jan 28, 2004)

*What is the length of the steerer?*

I ride a 49cm frame and am willing to bet that it would fit on my bike. Send it to me and I will try it for you and let you know if it is safe.


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## Lemondpoprad (Jan 22, 2004)

True Temper Alpha Q makes a aluminum insert that is glued to the inside of the tube so you don't crush the stear tube like you did. They sale these for around $30.00. IT will fix your problem.


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## Bonked (Nov 11, 2002)

i was about to post an update...and this is the solution i came up with! any idea where i can get one of these inserts?

i was poking around work for some epoxy yesterday to just fill up the tube with when someone mentioned to me that we just hired a guy who is a carbon genius. turns out he builds his own bikes, has worked with trek and fsa and is currently doing stuff with rossignol. his suggestion was to create a vacuum when applying the epoxy to actually suck some of it into the crack (which i will need his equipment for) and to then glue an aluminum insert into place inside the tube. i figure that when we are done, it will basically be like an aluminum steerer with a carbon wrap...kind of like the merckx team sc chainstays...this could be the wave of the future. i'm pretty certain that this solution will be fine and, more importantly, he thinks so too, but i've marked the top and bottom of the crack and will watch it closely for a while. i'll post a write-up when i'm done.

thanks for all of the suggestions!


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## bostonkiwi (Feb 4, 2004)

Bonked said:


> i was about to post an update...and this is the solution i came up with! any idea where i can get one of these inserts?


I have a spare alpha q Al insert complete with factory installed starnut, if you are still looking PM me.


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## ACarter42 (May 28, 2004)

*More info on alpha Q insert?*



Lemondpoprad said:


> True Temper Alpha Q makes a aluminum insert that is glued to the inside of the tube so you don't crush the stear tube like you did. They sale these for around $30.00. IT will fix your problem.


 Know who can get these? emailed CC and excel, both listed as alpha Q distr.


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## Bonked (Nov 11, 2002)

don't know...this (http://forums.roadbikereview.com/showthread.php?t=5203) is what i ended up doing...

good luck!


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