# Reinforcing carbon fiber steerer tube



## Waspinator (Jul 5, 2013)

Please, don't bother responding to this question with statements like "why bother?" or "what's the point?". I am asking this more as an academic question more than anything else.

If one wanted to reinforce a carbon-fiber steerer tube (along the entire length of the tube), what approaches could be taken to do this that wouldn't add too much weight?

For example, I was thinking that mixing epoxy with small styrofoam pellets, and filling the steerer tube with it (to create somewhat of a "pneumatized" structure like the long bones found in birds, which are extremely strong) might be one option. Any other ideas? A thin-walled tube of smaller diameter glued into the steerer tube could be another approach, perhaps?

Also, I'm wondering: are steerer tubes on forks actually carbon-fiber, or something else? They don't seem to have the glossy epoxy finish and carbon-fiber cross-hatched weaved cloth that you find in other carbon fiber parts. Would epoxy even bond to it?


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## pulser955 (Apr 18, 2009)

What do you want to accomplish? There are a few plugs that will reinforce the tube at the stem to prevent crushing. I don't know that you really need any reinforcement any place other than that.


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## My Own Private Idaho (Aug 14, 2007)

You could use an aluminum sleeve, bonded inside the carbon post.


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## tihsepa (Nov 27, 2008)

What are you trying to accomplish?
Undamaged steer tubes are not just breaking off all the time.


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## Waspinator (Jul 5, 2013)

pulser955 said:


> What do you want to accomplish? There are a few plugs that will reinforce the tube at the stem to prevent crushing. I don't know that you really need any reinforcement any place other than that.
> 
> View attachment 290236


To my knowledge, no one has ever snapped off an aluminum steerer tube while riding a road bike. CF steerer tubes are a different story, if I'm not mistaken. And let's face it, a steerer tube is an absolutely lousy place for a bike to fail. There are a lot of us - especially bigger cyclists - who are quite frankly squeamish about CF steerer tubes.

Steerer tubes are take a lot of forces in a wide variety of directions while essentially keeping the front half and the back half of a bicycle together as one functioning unit. They are the cycling equivalent of the Jesus pin on a helicopter (which keeps the main rotor attached to the main shaft). As such, they ought to be outright bomb-proof. I personally think that CF steerer tubes epitomize irresponsible design, but unfortunately, nowadays if you want a top-end bike you're going to get a CF steerer. There ought to be a way to add strength to them without increasing the weight too much.


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## looigi (Nov 24, 2010)

Cervelo uses an epoxy in aluminum plug instead of an expanding plug. This reinforces the steerer near the top headset bearing and stem. If the diameter fits your fork, this would be a good way to go. If not, fabricating something similar would good. Further down in the steerer? If it had to be done, you could lay in some pre-preg unidirection CF, a balloon, and cure it...


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## Waspinator (Jul 5, 2013)

tihsepa said:


> What are you trying to accomplish?
> Undamaged steer tubes are not just breaking off all the time.


Cyclists don't fall off their bikes all the time either, but they still wear helmets. We're talking about taking precautions. Steerer tube breakage is catastrophic.


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## tihsepa (Nov 27, 2008)

Waspinator said:


> To my knowledge, no one has ever snapped off an aluminum steerer tube while riding a road bike. CF steerer tubes are a different story, if I'm not mistaken. And let's face it, a steerer tube is an absolutely lousy place for a bike to fail. There are a lot of us - especially bigger cyclists - who are quite frankly squeamish about CF steerer tubes.
> 
> Steerer tubes are take a lot of forces in a wide variety of directions while essentially keeping the front half and the back half of a bicycle together as one functioning unit. They are the cycling equivalent of the Jesus pin on a helicopter (which keeps the main rotor attached to the main shaft). As such, they ought to be outright bomb-proof. I personally think that CF steerer tubes epitomize irresponsible design, but unfortunately, nowadays if you want a top-end bike you're going to get a CF steerer. There ought to be a way to add strength to them without increasing the weight too much.


Makes sense. To be honest I am more worried about the aluminum steer tube bonded to the carbon fork than a full carbon fork.


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## pulser955 (Apr 18, 2009)

Waspinator said:


> To my knowledge, no one has ever snapped off an aluminum steerer tube while riding a road bike. CF steerer tubes are a different story, if I'm not mistaken. And let's face it, a steerer tube is an absolutely lousy place for a bike to fail. There are a lot of us - especially bigger cyclists - who are quite frankly squeamish about CF steerer tubes.
> 
> Steerer tubes are take a lot of forces in a wide variety of directions while essentially keeping the front half and the back half of a bicycle together as one functioning unit. They are the cycling equivalent of the Jesus pin on a helicopter (which keeps the main rotor attached to the main shaft). As such, they ought to be outright bomb-proof. I personally think that CF steerer tubes epitomize irresponsible design, but unfortunately, nowadays if you want a top-end bike you're going to get a CF steerer. There ought to be a way to add strength to them without increasing the weight too much.


They make suspension forks with carbon steerer tubes. To my knowledge they don't fail very often and they are subjected to much harsher forces than any thing you're going to do on the road. Carbon is much stronger than aluminum. The problem is when people crush the tube with the stem. Other than that I don't really know of any wide scale problem with carbon tubes.


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## tihsepa (Nov 27, 2008)

Get a steel bike.
I tour on a Surly LHT. The fork will hold up fine.


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## Waspinator (Jul 5, 2013)

tihsepa said:


> Makes sense. To be honest I am more worried about the aluminum steer tube bonded to the carbon fork than a full carbon fork.


Good point. That certainly does raise questions too.

However, the carbon fiber around the stem is particularly vulnerable. It's being squeezed by stem, pulled side to side by the rider, all while supporting _some_ of the rider's weight (which can increase dramatically when hitting bumps). And its doing all of these things right above the upper headset bearing.


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## PlatyPius (Feb 1, 2009)

Waspinator said:


> Please, don't bother responding to this question with statements like "why bother?" or "what's the point?". I am asking this more as an academic question more than anything else.
> 
> If one wanted to reinforce a carbon-fiber steerer tube (along the entire length of the tube), what approaches could be taken to do this that wouldn't add too much weight?
> 
> ...


why bother?
what's the point?


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## BlueMasi1 (Oct 9, 2002)

Wood dowels.


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## Guod (Jun 9, 2011)

I think someone with industry knowledge needs to respond to this.

Personally, I worry more about whether or not I put sufficient tension on my quick releases on my wheels. I've hit potholes hard enough to cause my bars to slip in the stem clamp and nothing happened to the steerer. Note to alarmists: my bars and stem are both alloy, torqued to spec. I think it's needless worry to be paranoid about the steerer, just like my paranoia about quick releases.


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## velodog (Sep 26, 2007)

Waspinator said:


> To my knowledge, no one has ever snapped off an aluminum steerer tube while riding a road bike.


When Hincapie's steerer broke in the 2006 Paris Roubaix, taking him out of the race with a separated shoulder, it was an aluminum steerer bonded to a carbon fork. The break was just below the stem clamp, which means the steerer broke not the aluminum to carbon bond.

Stuff happens.


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## velodog (Sep 26, 2007)

BlueMasi1 said:


> Wood dowels.


When I was a kid a friend had a 165cc motorcycle and he wanted a chopper, so he stole a broom from his mother and cut two six inch sections out of the handle and forced them into the forks to extend them. He took his "chopper" with the six inch extended forks out for its maiden voyage and didn't even get around the block before the modification failed catastrophically.

He busted up his face pretty good, and all any of us did to help was laugh our asses off. It was one of those things that you never forget.


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## cxwrench (Nov 9, 2004)

My Own Private Idaho said:


> You could use an aluminum sleeve, bonded inside the carbon post.


^ This would work. As someone else posted, it's how Cervelo does it. ^


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## redondoaveb (Jan 16, 2011)

cxwrench said:


> ^ This would work. As someone else posted, it's how Cervelo does it. ^


Alpha Q does it with their forks also.


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## brianmcg (Oct 12, 2002)

You could buy a Surly Pacer and have no worries at all.


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## Insight Homewood (Aug 15, 2013)

I suggest you ask the manufacturer of your carbon fiber fork/steerer tube what strength it has vs an aluminum one. The very best springs made are now carbon fiber because they can be designed with a fatigue life far beyond what normal mortals would be able to apply to them. As far as I know, the main bicycle manufactures are not on the carbon fiber bandwagon as a fad; they are afraid of product safety recalls that could sink a company. For that reason alone, carbon bikes are over-designed in strength and fatigue strength to make them as bombproof as possible. Calfee Design, in their dragon fly bike, mix carbon fiber with boron fiber to make the tubes much tougher for the weight and damage-resistant.
:aureola:


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## lbkwak (Feb 22, 2012)

Waspinator said:


> To my knowledge, no one has ever snapped off an aluminum steerer tube while riding a road bike. CF steerer tubes are a different story, if I'm not mistaken. And let's face it, a steerer tube is an absolutely lousy place for a bike to fail. There are a lot of us - especially bigger cyclists - who are quite frankly squeamish about CF steerer tubes.
> 
> *Steerer tubes are take a lot of forces in a wide variety of directions while essentially keeping the front half and the back half of a bicycle together as one functioning unit.* They are the cycling equivalent of the Jesus pin on a helicopter (which keeps the main rotor attached to the main shaft). As such, they ought to be outright bomb-proof. I personally think that CF steerer tubes epitomize irresponsible design, but unfortunately, nowadays if you want a top-end bike you're going to get a CF steerer. There ought to be a way to add strength to them without increasing the weight too much.


Don't you think engineers thought of that before and design carbon forks?

If you are worried, you should ask tandem riders how they do it. I've seen a 350lbs tandem team using a Enve Road 2.0 since it was available without an issue. Btw, both Enve and Whiskey forks have 350lbs. rating.

Unless you are heavier than the tandem riders, I don't think you need to worry.


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## scott967 (Apr 26, 2012)

Interesting question. I can see intuitively there is the idea that "more" is better than "less", but when I think of a multi-layer CRF layup, it seems really hard just to assume how the stress is managed. My fear would be that by reinforcing one point, it just moves the stress concentration somewhere else (but I'm not a materials or structures guy, so what do I know). If I was doing it without the benefit of knowledge, I would want to build some examples and conduct instrumented test to failure to see what happens. Boeing 777 Wing Test.

scott s.
.


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## wetpaint (Oct 12, 2008)

This was an aluminum steerer.... Anything can break, your fear over carbon steerers is irrational.


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## cxwrench (Nov 9, 2004)

Most of the posters that have replied so far should probably re-read the OP's very first sentence. Just sayin'...


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## Cinelli 82220 (Dec 2, 2010)

Serious answer.

I would epoxy in a stiffening rib in a fore-aft plane of the steerer, so the steerer is divided into two "D" shapes. As long as the inner diameter of the steerer is consistent this should be fairly easy. Some manufacturers use a similar stiffening rib in their downtubes or chainstays.

Gluing in a tubular metal reinforcement is not as good an idea as it sounds. The metal tube and carbon steerer will have different modulus of elasticity. When the steerer deforms under load, one will bend more than the other. This puts a shear stress on the adhesive and the bonded layer of the carbon, which could theoretically lead to delamination. This is also why I don't like frames that are metal/carbon hybrids, I have seen carbon stays detach from aluminum frames. 

Carbon steerers usually have kevlar or similar material in the weave to prevent catastrophic failure.


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## Waspinator (Jul 5, 2013)

wetpaint said:


> This was an aluminum steerer.... Anything can break, your fear over carbon steerers is irrational.


I see. So your conclusion from this video is that this rare aluminum steerer breakage means that aluminum steerers and CF steerers are equally prone to breakage.

Your interpretation of statistics is below remedial, my friend. Seriously, there are few things that drive me up the wall more than people who make conclusions based on isolated anecdotes.

CF steerers, despite being around for well under a decade and only on a small percentage of bikes, have broken on _many _occasions. Aluminum steerers have been pretty much standard on all bikes for two decades easily, and _rarely _break.


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## tihsepa (Nov 27, 2008)

Waspinator said:


> I see. So your conclusion from this video is that this rare aluminum steerer breakage means that aluminum steerers and CF steerers are equally prone to breakage.
> 
> Your interpretation of statistics is below remedial, my friend. * Seriously, there are few things that drive me up the wall more than people who make conclusions based on isolated anecdotes.*
> 
> CF steerers, despite being around for well under a decade and only on a small percentage of bikes, have broken on _many _occasions. Aluminum steerers have been pretty much standard on all bikes for two decades easily, and _rarely _break.


No kidding, have you ever read anything posted here by that Waspinator guy?


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## velodog (Sep 26, 2007)

Waspinator said:


> Also, I'm wondering: are steerer tubes on forks actually carbon-fiber, or something else? They don't seem to have the glossy epoxy finish and carbon-fiber cross-hatched weaved cloth that you find in other carbon fiber parts. Would epoxy even bond to it?





Waspinator said:


> I see. So your conclusion from this video is that this rare aluminum steerer breakage means that aluminum steerers and CF steerers are equally prone to breakage.
> 
> Your interpretation of statistics is below remedial, my friend. Seriously, there are few things that drive me up the wall more than people who make conclusions based on isolated anecdotes.
> 
> CF steerers, despite being around for well under a decade and only on a small percentage of bikes, have broken on _many _occasions. Aluminum steerers have been pretty much standard on all bikes for two decades easily, and _rarely _break.



Yours is a mighty high handed response from somebody who doesn't even know what a carbon steerer is made out of.


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## mikerp (Jul 24, 2011)

Fill it with an unobtainium poly matirx.


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## myhui (Aug 11, 2012)

Waspinator said:


> If one wanted to reinforce a carbon-fiber steerer tube (along the entire length of the tube), what approaches could be taken to do this that wouldn't add too much weight?


( per cxwrench's request, I am responding to the OP)

If you are allowed to modify the manufacturing process, then I would put in discs ( also made of CF ) that are tightly bonded to the walls of the tube at regular intervals down the length of the tube. The discs are perpendicular to the tube's length.

I saw this principle explained on a video made by professors in an engineering school who were trying to attract students to enroll in the school: a cylinder that is hollow at the end is very weak. But if you put on caps, and bond them tightly to the tube, then it becomes very strong. That is how airplane fuselages are reinforced: by putting in bulkhead sections at regular intervals down the tube.


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## myhui (Aug 11, 2012)

BlueMasi1 said:


> Wood dowels.


IKEA should sell a self assembled wooden bike made of wood from a very light species of tree. Can you imagine the flood of new posts here if their instructions aren't clear enough?


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## cxwrench (Nov 9, 2004)

Waspinator said:


> Also, I'm wondering: are steerer tubes on forks actually carbon-fiber, or something else? They don't seem to have the glossy epoxy finish and *carbon-fiber cross-hatched weaved* cloth that you find in other carbon fiber parts. Would epoxy even bond to it?


This is a 'finish' layer, not the actual structural carbon fibre material. It is included by some manufacturers because some people (like you) expect to see the 'weave' where carbon fibre is involved.


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## Waspinator (Jul 5, 2013)

cxwrench said:


> This is a 'finish' layer, not the actual structural carbon fibre material. It is included by some manufacturers because some people (like you) expect to see the 'weave' where carbon fibre is involved.


Wrong.

This weave is actually carbon-fiber cloth, and is used to make many carbon fiber parts - including bike parts. It is every bit “structural" in nature. Don’t believe me? Go see a Ferrari, Lamborghini, Formula One, or IndyCar chassis being made.

I am fully aware that CFRPs can be made with ‘directional’ strength, in which case a woven organization of carbon tows may not be optimal. One would think, however, that a steerer tube wouldn’t necessarily be stronger by having its carbon fiber tows only in parallel.


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## mikerp (Jul 24, 2011)

Waspinator said:


> Wrong.
> 
> This weave is actually carbon-fiber cloth, and is used to make many carbon fiber parts - including bike parts. It is every bit “structural" in nature. Don’t believe me? Go see a Ferrari, Lamborghini, Formula One, or IndyCar chassis being made.
> 
> I am fully aware that CFRPs can be made with ‘directional’ strength, in which case a woven organization of carbon tows may not be optimal. One would think, however, that a steerer tube wouldn’t necessarily be stronger by having its carbon fiber tows only in parallel.


While the outside visible layer does add the overall structure of the component, many parts/components are available with your choice of "cosmetic" layer. I personally could not pass a "blind" part test to determine the difference between out weaves.
Examples: Ritchey provides the same parts in a weave as well as unidirectional.
Chinese Carbon frames and rims are offered with a choice of weave.

From Yeoleo
Carbon fiber is measured by the width of the weave. For instance, a 1K weave will be approximatley 1mm in width while a 12K weave will be much larger at approximatley 12mm and so forth.


The outer layer of any carbon frame serves several purposes. The first purpose is to provide a cosmetic layer of carbon giving the frame it's final look. Secondly, it provides a final touch to the ride of the bicycle. Some weaves are more rigid than others and some weaves flex more providing more supple ride characteristics. Some people will say that the weave you choose does not make a difference in overall ride quality. If that is the case then our Fascenario 0.7 and 0.8 should produce the exact same stiffness numbers, as they are made the same with the only difference being the outer layer of carbon. The fact is that the 12K carbon used in the Fascenario 0.8 makes the bike stiffer and can be seen in stiffness-to-weight measurements.

So, what are the characteristics of each weave that Storck uses in relation to our bicycles?

1K - 1K is a very rare fiber used in the cycling industry. It is lighter than other fibers and provides a more supple ride than a larger weave. These smaller carbon fibers also display the incredible amount of craftsmanship needed to complete one of our bikes. The Fascenario 0.7 is the only model in the Storck line that features this coveted carbon.

2K - 2K is the rarest carbon fiber available on the market. It is produced by no more than 2 carbon manufacturers in the world. The Fascenario 0.7IS is the only bicycle in the world featuring this carbon. 2K carbon provides the optimum ride characteristics to pair with our VVC frames. This gives the bike perfect stiffness, low weight, and great vertical compliance (comfort).

3K - 3K is the most common carbon fiber that you will find externally on a bicycle. It provides a comfortable ride while still allowing the bike to be stiff and strong enough to handle a powerful rider in the midst of his/her best sprint.

12K - 12K is the largest weave and the stiffest. This outer layer featured on the Fascenario 0.8 makes for the stiffest "feeling" ride of all three. It is slightly heavier and much less expensive to use in production, hence the price difference in the Fascenario 0.7 and the Fascenario 0.8.


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## myhui (Aug 11, 2012)

Thanks for that info, mikerp.

I suppose unscrupulous manufacturers can cheat and change the weave for just the top visible layer too.


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## Cinelli 82220 (Dec 2, 2010)

Waspinator said:


> It is every bit “structural" in nature


Well it depends on what you mean by structural eh.

Sometimes the outer woven layer is not structural at all. It is there to protect the layers underneath from abrasion or impacts.


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## cxwrench (Nov 9, 2004)

Waspinator said:


> Wrong.
> 
> This weave is actually carbon-fiber cloth, and is used to make many carbon fiber parts - including bike parts. It is every bit “structural" in nature. Don’t believe me? Go see a Ferrari, Lamborghini, Formula One, or IndyCar chassis being made.
> 
> I am fully aware that CFRPs can be made with ‘directional’ strength, in which case a woven organization of carbon tows may not be optimal. One would think, however, that a steerer tube wouldn’t necessarily be stronger by having its carbon fiber tows only in parallel.


Well, since we're on RBR and we generally talk about bicycles here, why don't you tell about your personal experience w/ carbon fiber layup where bicycle parts are concerned. I'm all ears. 
Just remember, there is a certain amount of "been there, done that" when I'm involved.


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## DaveG (Feb 4, 2004)

I can see some merit to the idea of a reinforcing sleeve. I would imagine that most CF steerer failures are the result of over-torqing the stem bolts. While that is mechanic error, a sleeve might reduce that without adding a lot of weight. It would also allow higher torque values, thus reducing any chance of stem slippage


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## mikerp (Jul 24, 2011)

DaveG said:


> I can see some merit to the idea of a reinforcing sleeve. I would imagine that most CF steerer failures are the result of over-torqing the stem bolts. While that is mechanic error, a sleeve might reduce that without adding a lot of weight. It would also allow higher torque values, thus reducing any chance of stem slippage


Is there really a problem out there with CF steerer tubes failing?


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## mikerp (Jul 24, 2011)

What would be the benefit? If the parts start to fail, they won't be in business long.


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## DaveG (Feb 4, 2004)

Its certainly not an epidemic but you see posts here from time to time about folks damaging the steerer and the suspected cause is over-tightening the stem clamp. I hope you can agree that riding a bike with a cracked steerer is asking for a catastrophic failure. Because of user error, the steerer has to be one of the most damage prone areas of a frame. If I were a manufacturer I'd be worried about litigation even if it were the buyers fault.


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## velodog (Sep 26, 2007)

mikerp said:


> Is there really a problem out there with CF steerer tubes failing?


Probably not, but then there's just gonna be something else to worry about.


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## rebel1916 (Aug 4, 2007)

wetpaint said:


> This was an aluminum steerer.... Anything can break, your fear over carbon steerers is irrational.


Irrational is the polite word for it.


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## stanseven (Nov 9, 2011)

mikerp said:


> While the outside visible layer does add the overall structure of the component, many parts/components are available with your choice of "cosmetic" layer. I personally could not pass a "blind" part test to determine the difference between out weaves.


Thanks for the information. Also thanks for your very informed and knowledgeable replies on so many threads here. You are a valuable contributor and I really appreciate your participation.


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## aclinjury (Sep 12, 2011)

As Myhui pointed out, a hollow cylinder is weaker than the same cylinder being reinforced with cross-members. And these cross-members can be "discs" bonded at regular intervals. 

Fuji also use these cross-members in their downtube; Fuji calls it "ribs" (same concept, different name).

You can also use "honeycomb" reinforcement. Take a honeycomb structure and shove it down the hollow steerer tube, and bond them together. Honeycomb structure itself can be made of aluminum or carbon fiber.

The above 2 solutions are not easy to execute. You would need to be an expert in the field of carbon fiber and materials to reinforce it soundly sucessfully. Do you even have the equipment and resources to make it happen?

The much cheaper alternative is to drop in an aluminum sleeve like Cervelo. But as Velodog pointed out, aluminum and carbon fiber expand (and flex) differently. So you would need to understand the characteristic of the combined structure, and you would need to use the right epoxy too (because often times the damage is to the epoxy layer in addition to the fiber and/or aluminum contituents). Personally, I don't like this method. It's an in-the-field bandaid solution.

The other cheap method is use a reinforcing expander plug at the stem clamp area. This of course only reinforces the clamp area, and not the whole length of the steerer. But reinforcing the clamp area still provides additional margin of safety.

Honeycomb is probably the best overall solution since this will not only reinforce the whole length of the steerer, but also at the stem clamp area. Discs solution may not reinforce the clamp area. Sleeve and expander-plug reinforce the clamp area, but not the whole steerer. Honeycomb solution is probably gonna cost too much to even consider.

Specialized a while back had a recall on some of their carbon forks. The recall involves the steerer breaking if you had a lot of spacers underneath the stem. A cases did in fact happened. Specialized solution was to use some sort of sleeve too. I don't recall the exact nature of the recall though.

Having said this, if you are a heavy person and have a real fear in your carbon steerer tube, and you are not an expert in working with carbon fiber, then the elegant solution is to buy a more robust fork. You can get a used Alpha Q fork for cheap (one of the strongest fork out there). You can also get the Enve 2.0 fork (a new one can be bought online for well under msrp price). DON'T get the Enve 1.0 fork as this a weightweenie and has thinner cylindrical wall. The Alpha Q or Enve 2.0 solution will cost about $200 - $300. 

If this was not an academic question, and safety was a real concern, then I'd get an Enve 2.0 or Alpha Q and call it a day. No question about it.


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## Reynolds531 (Nov 8, 2002)

I am on an engineering design safety committee at a Fortune 100 company. Making modifications like you are describing is much more complex with many more factors to consider than most people can imagine. making changes without proper design, review, execution and control is far riskier than riding a bike with a CF steerer tube. Many disasters are caused by improper management of change.


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## stanseven (Nov 9, 2011)

velodog said:


> Probably not, but then there's just gonna be something else to worry about.


It's really amazing how worried people get about ridiculous things. I've had seatpost clamps break, a friend that a saddle rail snap, and I had a front skewer come apart. Those are all more likely than a steerer tube. Of course after saying that, probably many people are thinking "oh, oh!" 

Realistically there are so many more likely things that happen like getting hit by a car, sliding on an oily spot on the road or ice, hitting a pothole, being chased by a dog, hit my another cyclist, etc. 

Just ride and enjoy it and stop worrying.


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## mikerp (Jul 24, 2011)

Glad you touched on this point, as soon as you mod something the manufacturer is not liable for any issues. So while you may think you are making something better, you are taking on all the issues with it if you have a failure.


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## scott967 (Apr 26, 2012)

This article suggests steerer failure is a problem and not always well tested for:
Cervelo founder calls for industry-wide fork steerer test - VeloNews.com

scott s.
.


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## DaveG (Feb 4, 2004)

stanseven said:


> It's really amazing how worried people get about ridiculous things.


You mean like Cervelo? (see posted article below)


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## stanseven (Nov 9, 2011)

DaveG said:


> You mean like Cervelo? (see posted article below)


Someone is far more likely to experience a bar snapping, a seatpost falling apart, a defective tire blowing, or any number of things that a steerer snapping. I like Cervelo and have one. But don't you see a self serving motive here for Cervelo with this article? If the problem was bad, lots of other people in teh industry would be complaining and drawing attention to it.


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## myhui (Aug 11, 2012)

Use carbon glue between stem and steerer tube, so that you can use the least amount of clamping force.


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## Cinelli 82220 (Dec 2, 2010)

stanseven said:


> If the problem was bad, lots of other people in teh industry would be complaining and drawing attention to it.


I don't personally know a single person who has broken a carbon steerer.

The Hincapie video is a red herring. He had crashed previously and kept riding the damaged bike instead of changing it. The stress a big guy like him, in Paris Roubaix, applies has little relevance to recreation riders.


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## rebel1916 (Aug 4, 2007)

Cinelli 82220 said:


> I don't personally know a single person who has broken a carbon steerer.
> 
> The Hincapie video is a red herring. He had crashed previously and kept riding the damaged bike instead of changing it. The stress a big guy like him, in Paris Roubaix, applies has little relevance to recreation riders.


Not to mention, as was stated previously, it was a #$%#^& aluminum steerer!


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## Camilo (Jun 23, 2007)

Waspinator said:


> Good point. That certainly does raise questions too.
> 
> However, the carbon fiber around the stem is particularly vulnerable. It's being squeezed by stem, pulled side to side by the rider, all while supporting _some_ of the rider's weight (which can increase dramatically when hitting bumps). And its doing all of these things right above the upper headset bearing.


Yea, I wonder if they've ever had any engineers or experienced bicycle designers look at that problem?


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## velodog (Sep 26, 2007)

Waspinator said:


> I see. So your conclusion from this video is that this rare aluminum steerer breakage means that aluminum steerers and CF steerers are equally prone to breakage.
> 
> 
> CF steerers, despite being around for well under a decade and only on a small percentage of bikes, have broken on _many _occasions. Aluminum steerers have been pretty much standard on all bikes for two decades easily, and _rarely _break.





Waspinator said:


> To my knowledge, no one has ever snapped off an aluminum steerer tube while riding a road bike.


So, do aluminum steerers never break or rarely break?


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