# Bianchi Carbon Fork Warning



## GKSki

I stumbled across a safety warning on Bianchi's global site. This has to do with possible catastrophic failure of full carbon forks with carbon steerer tubes when assembled incorrectly. I checked Bianchi USA's site and there is no such recall/warning and no mention of the issue. Additionally, I had registered my Bianchi on BianchiUSA.com (and this information was actually logged on the global site in Italy), yet I did not receive notification of the possible problem.

The main theme of the warning is that they are claiming that stems and spacers were installed incorrectly on Sempre Pros and Intensos, but not limited to these models. They state that assembling with more than a 5mm spacer above the stem can cause damage to the steerer tube.

Interestingly, when I went into the full details and instructions, they also said that a 5mm spacer was required under the stem (and not more than 35mm) and they also said that carbon assembly paste was not to be used on the steerer tube for stem installation.

Now, my Intenso was set up with 10mm above the stem and below I had the 3mm alloy washer between the stem and the headset top cap. I recently swapped out the Reparto Corse stem for a FSA SL/K stem and flipped the 3mm alloy washer above the stem to get a lower position. Oddly the FSA instructions required me to use carbon assembly paste and now Bianchi states that is not to be done.

So I guess I will have to pull it apart and do the steerer tube inspection they are urging. Then reassemble without the carbon paste and that just doesn't make sense. I will lose my position as I am going to be required to put a 5mm spacer below the stem, and I will have to find a Bianchi dealer (mine ended business) to cut the steerer tube a few milimeters.


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## MMsRepBike

Few comments here, let me start with the instructions from FSA and the assembly paste.

Are you certain it told you to use it on the interface of the stem/steerer? It is to be used on the interface with the handlebars, but NOT with the steerer tube. If FSA is giving instructions to use it with the steerer tube there is a serious problem here.

Secondly, let's just make it very clear for everyone what Bianchi is saying. They are saying that your compressing plug must rest inside of the stem. Not above it, not below it, directly inside of it. There are NOT to be any stem clamping bolts used in an area not supported by the compression plug. The compression plug is there preventing the stem from crushing the steerer tube.

So, with that said, it works both ways. Forget about the numbers real quick and just make sure you understand the concept. You can't have a bunch of steerer above the stem, with the plug up there too, so that the stem is clamping on a hollow steerer tube. Also you cannot cut the steerer so short that the stem leaves a big gap above it, having the top stem clamp clamping nothing but air. See this video below:






These morons better take this video down as the right way to do things and they better learn how headsets and compression plugs work. Never have your bike setup like in this video. See how the top stem bolt is not clamping anything? Granted, the other way around is worse for the steerer, but both are wrong.


And from me to you, you do not need a 5mm spacer under the stem. That's ridiculous.


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## GKSki

MMsRepBike said:


> Few comments here, let me start with the instructions from FSA and the assembly paste.
> 
> Are you certain it told you to use it on the interface of the stem/steerer? It is to be used on the interface with the handlebars, but NOT with the steerer tube. If FSA is giving instructions to use it with the steerer tube there is a serious problem here.


"3. Apply small amount of FSA Dynamic installation compound on steerer tube, if it is carbon. Install the stem body ① onto the steerer tube"


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## MMsRepBike

bah. 

The reasons I don't like that company are many.

I know some people, for whatever reason, grease that interface, but I advocate that it should be dry. No lubricants at all. I can't argue against grease really, but carbon paste is just stupid. That's just asking for damage to the steerer. I think FSA is in the wrong here.

And for the record, the Carbon Ti plugs they often use are also pretty bad. The amount of support they offer is minimal at best. If they took the lead from Colnago and used those long and very supportive plugs, I bet this wouldn't have ever happened.


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## GKSki

Here's where I found he warning, Bianchi - Performance bicycles since 1885.

I appreciate and agree with your direction regarding the compression plug. When I swapped out my stem and also moved the small spacer from below the stem to above the stem, I made sure that the plug was centered inside the stem. I think Bianchi compounds the problem by using such a minimalist compression plug (see the intructions in the warning).

Still, none of the Bianchi warning goes into details about the plug, instead concentrating on where and how much spacers there are.

Again, I agree with your take on this but I wonder if you were a Bianchi dealer, for liability reasons, would you be doing the installation according to their new instructions?

thx,


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## MMsRepBike

I don't follow all of the manufacturer instructions of things. If so I'd be putting carbon paste on steerer tubes. 

Some companies say "no spacers above the stem" and some say "5mm spacer mandatory under stem" and some say other things. Well... the real world interferes with things.

In a shop bikes have to be set up for testing, and the stem moves around a lot. That's a problem for those little minimalist compression plugs, makes certain positions not possible to test with while following instructions. So... I understand how things work. I understand why things are said, I know how to prevent the damage, so that's what I do.

We have lots of extra very long plugs in the shop. They go in almost everything. They end up staying in many bikes after the sale if someone wants spacers above the stem. This means that I break the instructions but still have the steerer fully supported. What I don't do is ever let a bike leave with part of the steerer or stem unsupported. It doesn't really matter what they have to say about it, I make sure it won't happen.

But do shops carry those long and supportive plugs that allow spacers above the stem? Nope. Do shops even understand the concept of not crushing a carbon steerer? I wouldn't bet on it. Looking around at these places, like the one posting that video above, I think it's clear that most don't even understand how things work. I think even Bianchi is clueless. They passed off their plugs to FSA and Carbon Ti and both did a horrid job. It's as if they don't know any better. Meanwhile Colnago has this licked. Pinarello does a fine job too. Bianchi should be in that boat, but nope, they're in this boat now instead.

TLDR: If I do the job right, there will be no liability, there will be no breakage. If I follow their instructions (FSA and Bianchi, using that crap plug), there might be a problem. If someone needs spacers above the stem, there will be one. I do it my way, the right way, the steerer and stem are always supported when it leaves the shop. That means often times I have to use a different, much longer and more supportive plug, but I do whatever it takes to ensure the steerer is safe. 

Safety is the key and Bianchi needs to do a better job. They need better plugs and better understanding. They need to look no further than Colnago.


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## GKSki

Guess I will take it in and have the steerer tube shortened so that I just have a 5mm spacer on top. Right now the stem is "slammed" (although the HS dustcap is still installed below the stem and I think the pros are even removing that), with a 10mm spacer and the 3mm alloy ring that I flipped from bottom to top both above the stem. It wouldn't hurt my peace of mind if I got a longer compression plug. Although as currently assembled, I think I paid enough attention to assembly to make sure the plug was fully supporting the tightening of the stem bolts.


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## GKSki

I have asked my contact at FSA to comment on the discrepancy betwee instructions from Bianchi and FSA.


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## MMsRepBike

Great, I'd like to hear what FSA has to say for themselves.

I did take a gander at the instructions and I don't see any reason for the 5mm under the stem they state. They give correct warnings for all of the warning things, but that particular nugget carries no warning if not followed.


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## Srode

Trek says the same thing about 5mm minimum under the stem.


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## wim

MMsRepBike said:


> I can't argue against grease really, but carbon paste is just stupid.


Curious about why grease would be OK, but carbon paste not. Trying to figure this out by myself, but I'm missing something, I think.


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## GKSki

FSA got back to me, and to paraphrase they said that they recommend using carbon assembly paste all the time, except if the bike/fork manufacturer says not to.

I guess they've got things covered, but there should be more cooperation among manufacturers.


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## MMsRepBike

wim said:


> Curious about why grease would be OK, but carbon paste not. Trying to figure this out by myself, but I'm missing something, I think.


I don't think grease is okay, I think it has no place there, but I have a hard time proving it causes any trouble. Grease does not just degrade carbon, so it's not going to eat it away. 

Again, I see zero reason for grease there, it's counter-intuitive if you ask me, but I don't see it causing harm outside of a slippery stem.

Now is a slippery stem a problem on it's own, worthy of arguing against grease? Maybe. It might cause the pinch bolts to have to be slightly tighter to hold correctly and prevent the stem slipping left/right. But then again maybe it isn't really a problem there. Why take the risk of a slipping stem? Ask someone that greases that interface.

The argument I've heard several times is that "I've always greased that interface and never had a problem." I can't really argue against that. Let's be honest here as well, most mechanics when installing a fork get some grease on the steerer from the bearings. Most mechanics then will do no better than just wiping it off with a rag or whatever. That will not remove the grease from the steerer entirely. What I do, once the bearings and everything but the stem is ready, is clean the steerer with rubbing alcohol. That way no grease residue is left at the interface with the stem. But how many do that? Probably less than 1%. So honestly most of the time this interface is probably lightly greased.



GKSki said:


> FSA got back to me, and to paraphrase they said that they recommend using carbon assembly paste all the time, except if the bike/fork manufacturer says not to.
> 
> 
> I guess they've got things covered, but there should be more cooperation among manufacturers.



Hmmm... That's really pushing it. I'm no lawyer but there seems to be a pretty solid case against FSA if you ask me in terms of steerer tube failures. "We tell you to destroy your steerer, but don't do it if the manufacturer tells you not to." That doesn't cut it if you ask me. I think they're liable.


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## GKSki

Well I don't think their qualified recommendation to use carbon paste has anything to do with steerer tube failures. I mean, you've well pointed out that those failures can mainly be attributed to the compression plug being located incorrectly, the combination of too long a steerer, wrong amount and/or position of spacers.

What I do think carbon past can cause is perhaps limiting the turning of the bars in a crash and the chance that the silica component of the carbon paste could somehow work its way downwards into the headset bearings where it could cause damage.

Back in the day, when I raced, we mainly had quill stems, Ciinelli XAs, 3TTT Model 84, and we greased them as we were mating alloy to alloy. Also, and perhaps because of this, in a crash the handlebars could turn and maybe more importantly could be wacked back into a straight position.


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## wim

GKSki said:


> What I do think carbon past can cause is perhaps limiting the turning of the bars in a crash.


That was sort in the direction my thoughts were going. You do need friction for a good stem-to-steerer connection, and carbon paste increases that friction. But you're right about not wanting a bomb-proof connection. That stem should rotate if a huge force acts on it, as if in a crash.

It occurred to me that with carbon paste, having the bars knocked offset during a crash (or forcefully straightening an offset bar without loosening the clamp bolts) could scratch the steerer perhaps to the point of compromising the clear coat if there is one.

@MMsRepBike: thanks for your interesting observations.


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## GKSki

Hadn't thought about that. Maybe that's why we haven't seen a mechanic from a team car jump out and knock someone's bars straight after a crash recently. I will have to pay more attention as maybe now those are just straight bike changes.


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## coldash

I don't really get this. I'm working away right now and these numbers might be a bit out but from memory my Sempre Pro was supplied with about 15mm below stem and 10mm above. I've changed this to 5mm below and 20mm above. The fork looked perfect when I did this and I moved the bung down so that it was aligned with the stem. I haven't cut the steerer yet but the top cap pressures the spacers and the carbon bit above the stem has no internal or external pressure on it, so what's the problem? And I would be very grateful for any advice if there is


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## GKSki

coldash said:


> I don't really get this. I'm working away right now and these numbers might be a bit out but from memory my Sempre Pro was supplied with about 15mm below stem and 10mm above. I've changed this to 5mm below and 20mm above. The fork looked perfect when I did this and I moved the bung down so that it was aligned with the stem. I haven't cut the steerer yet but the top cap pressures the spacers and the carbon bit above the stem has no internal or external pressure on it, so what's the problem? And I would be very grateful for any advice if there is


Well I can tell you that I wrote an EMail to Bianchi USA asking why they are not publicizing this and given that we registered our frames on their site, why are we not given notification? If you go to the global site, Bianchi.com you'll see the warning prominently displayed. With the MLK holiday, have not heard back yet.

My stem was "slammed" to the HS top cap with 13mm above it (the only reason that I didn't cut it even further was in case I had to go back to being more upright or needed to sell the bike.). You'd think that 13mm of adjustment flexibility wouldn't be too much.


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## coldash

GKSki said:


> My stem was "slammed" to the HS top cap with 13mm above it (the only reason that I didn't cut it even further was in case I had to go back to being more upright or needed to sell the bike.). You'd think that 13mm of adjustment flexibility wouldn't be too much.


Definitely agree on these points but I've never seen this before. It means that you can move the stem down but that is a once only change. It can never be raised because you have to cut the steerer tube. The reply to your email should hopefully be interesting


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## rm -rf

Very strange.

From the link above, examples (and there are more extreme ones, too).

The problem is *crushing * at the front of the steerer tube, right below the stem. You can see the circular shadow where the hollow part of the stem clamps the steerer.

Damaged









Undamaged









~~~~~~~~~~~~
From the *linked installation pdf* on the warning page. This shows both styles of FSA plugs. I have the left side one on my Infinito, with the very narrow plug body. (I have 10mm on top, and just pulled the stem to check, and there's no damage.)

Two plug styles
Note that the left side one shows the plastic cylinder!








Spacing measurements on the skinny plug








*Positioning!*
The pdf says 35mm to 40mm from the cap to the top of the plug.
With a 5mm spacer above the stem:
35mm puts the *top edge of the plug* right about the centerline of the bottom bolt.
40mm puts the top edge of the plug around 3 mm above the bottom edge of the stem -- so the plug extends below the bottom edge of the stem. That's right where the crushing occurs, so it looks like that's the critical support area.

I always tried to center the (longer) plugs so that they spanned both stem bolts, not near or below the bottom of the stem.

*The plug is pretty small.*
My plug is just about level with the bottom stem bolt. I wondered about the short height of the plug, it doesn't reinforce the steerer even half way to the top of the stem. Other plugs I've seen are much taller. 
*
Plastic cylinder insert*
See this previous thread of noisy headsets due to the loose insert.

The *plastic cylinder* is thick and substantial, looking like a purposely designed reinforcement. It's way sturdier than some kind of packing material. But it's outside diameter is *smaller *than the inside of the steerer, so it rattles around in there. I put mine back with some electrical tape around it so it's snug. 

The expansion plug and the mystery cylinder. EDIT--the cylinder *does *show up in the pdf photo of the two plugs. But it's not mentioned after that.
This is just about the most minimalist, lightest weight plug you could make.









EDIT-- see the next post, I may replace this plug. I'm going to trim the steerer a little bit and use a 5mm spacer, and measure the gap between the cap and plug like the pdf shows. I may leave the black cylinder off this time.


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## rm -rf

*FSA Plugs Confusion*

googling finds this longer compression plug on the FSA site.
The page says it's "Road-->Headset Spares-->Carbon Steerer compression device"
But the URL has it under ../products/cyclocross..

I don't see any plugs at all when navigating the site from the front page.
But typing in "compression" at the search box finds a page full. 
For carbon steerers, they only show this long style and the medium sized one from the install pdf. 

My short one isn't shown. Is it obsolete? Should I replace mine? I think I'm going to get a longer one, just so I don't have to think about it on bumpy 40 mph downhills!

This one on the FSA site is a* lot longer* than the plugs in the other Bianchi pdf:









It's the style with a top lip that sits on the cut edge of the steerer tube, instead of just staying in place by compression force.


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## coldash

It's going to be two weeks before I can look at my setup but I think it has the longer of the two types shown but in any case I can't see why the number of spacers above the stem is a problem unless they prevent the plug being positioned correctly wrt the stem. Once the plug is positioned correctly and torqued up, the top cap and the spacers could be removed without any problems, appearances apart. 

Hopefully Bianchi will clear this up, although I doubt it, before I get back to my bike.


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## vic bastige

Bianchi USA seems to have adopted a "no consumer level communication" approach. When I had a problem with my first Infinito, I was able to call them up in California and get immediate support that resulted in a frame replacement (GREAT warranty support). Now that my replacement frame has a crack in it, I couldn't find a published phone number anywhere and was only able to get a response from Bianchi International that directed me to an authorized dealer as my only option for contact with them. I get it, but it is a change and this time they have not been near as responsive.

I hope they weigh in on this soon as it will impact my re-build.


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## GKSki

rm -rf said:


> *FSA Plugs Confusion*
> 
> googling finds this longer compression plug on the FSA site.
> The page says it's "Road-->Headset Spares-->Carbon Steerer compression device"
> But the URL has it under ../products/cyclocross..
> 
> I don't see any plugs at all when navigating the site from the front page.
> But typing in "compression" at the search box finds a page full.
> For carbon steerers, they only show this long style and the medium sized one from the install pdf.
> 
> My short one isn't shown. Is it obsolete? Should I replace mine? I think I'm going to get a longer one, just so I don't have to think about it on bumpy 40 mph downhills!
> 
> This one on the FSA site is a* lot longer* than the plugs in the other Bianchi pdf:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> It's the style with a top lip that sits on the cut edge of the steerer tube, instead of just staying in place by compression force.


Good luck trying to find a place to buy the longer FSA plug. They just are not being sold. By the way, they make the longer plug with both an alloy and a carbon top cap. Same height and internal mechanism.


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## GKSki

The more I think about this the more it seems like a ridiculous safety restriction. In my setup, I only have 13mm on the steerer tube that is not the stem. My stem is a FSA SL/K and that takes the 40mm of the steerer tube. By this I am saying that it seems reasonable to allow me 13mm of extra length of the steerer. 

Of that, at least 5mm would have to be taken for a spacer above the stem to be able to get the preload on the bearings. Then, although I still cannot understand the rationale, they are requiring another 5mm spacer under the stem meaning by the Safety warning I am only 3mm above bounds albeit mainly above the stem.


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## coldash

Right, I've now been able to check my setup and I have 10mm below the stem and 25mm above (I've also checked my records and it was supplied with 25mm below and 10mm above). I've moved it down in 5mm increments and repositioned the plug each time. In its current position the plug is exactly in the middle of the stem between the clamping bolts. So...... the thing I don't get is what is achieved by chopping 20mm off the unstressed bit of the fork above the stem apart from making it look better but making the bike more difficult to sell?
PS I've also looked at the whole fork above the headset and there is no sign of damage or odd stress marks


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## GKSki

I agree that spacers above the stem should be less concerning than those below the stem and as long as the compressor is in the middle between the clamp bolts, how can there be an issue. What model Bianchi is yours? Mine is an Intenso.


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## coldash

Mine is a Sempre Pro 2013 model bought in 2014. My son has used it as well as myself, hence the playing about with various stem heights.


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## GKSki

Here is what my configuration looks like. Hard to believe there would be a problem with this. That's 13mm (10mm + 3mm) above the stem and 0mm below. SL/K stem is 40mm tall.


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## coldash

GKSki said:


> Here is what my configuration looks like. Hard to believe there would be a problem with this. That's 13mm (10mm + 3mm) above the stem and 0mm below. SL/K stem is 40mm tall.


Agreed and to take things to an extreme, assuming that the plug / bung is aligned with the middle of the stem, you could, after torqueing the bolts, completely remove the top cap and any / all spacers above the the stem. From a mechanical pint of view, the length of the fork above the stem is now completely irrelevant. 

The only case where I can see the number of spacers >5mm above the stem being of any importance is if the length between the top cap bolt and the plug was so great that the bolt could not properly engage with the plug i.e. wasn't long enough but this isn't the case with mine and that has 25mm of spacers above the stem.


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## Bee-an-key

I love the slammed stem look, wish I was flexible enough to go that low and PRO! That said, my mechanic sets up every bike with top and bottom spacers. Practical is leaving a little extra fork, not so much for re-sale value but for flexibility reasons of changing stems, age and bad backs. The mechanics would rather error on the safety side and have the extra top spacer. As the video shows, way to many bikes are out there with too short at tube. My .02$
Recall: my 2015 Sempre frameset had a fork recall before I was even able to build it. Never saw it published anywhere but my shop was notified and a new Chinese replacement was sent without issue.


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## kbwh

I find all this kind of funny. Sorry. But a lot has been lost in translation, as some have alleged to. 
If GKSki had used a "flat" 5 mm top cap he'd have room for that "all important" 5 mm spacer below the stem. Add a bit more spacer and the resulting stack would have been equal.

I do not use the original top cap and expander plug om my 13 Sempre Pro, but one that puts the expander plug in the right place. I use the same 15 mm top bearing cap as GKSki plus a 3 mm spacer below a FSA K-Force/OS99 stem. On top there is a 5 mm spacer. I used to run the 5 mm below and the 3 mm on top, but my last bike fit ended seat up 6mm, bars down 2mm. God I feel aero now.


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## GKSki

O.K. while I wait for further advice from Bianchi USA, I think I will put a 5mm spacer under my stem and a 5mm above. That leaves out the 3mm alloy spacer that is currently part of the stack and I am not sure I can get away without it. Does anyone remember how far above the steerer tube my spacers need to be so that I can preload the headset?

I also purchased an Origin8 compressor plug because it has 50mm of coverage and in theory should support the steerer tube much better in the area where the stem clamps.


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