# Thomson Seatpost Broke today



## apacherider (Mar 18, 2004)

I'm OK, which is the main thing. Seriously, if I had not been riding on smooth concrete, this would have been a compete disaster. Added help was that I have a small Cannondale seatbag for a spare tube under my seat with small velcro loop that goes around the post in addition to the seat rails. That's the only thing that saved me from an aluminun colonoscopy. I have 5 Thomson seatposts and never had an issue with any of them till today. Across those posts I have over 100,000 care free miles. Owned this particular post 10 months and about 2000 miles. It's a Thomson Setback 31.6 410mm I have been using in Cannondale Caffeine framesets. The post has never been dropped, wrecked, knock over or even put in a repair stand.

Frankly I did not think this was possible because I read that the bolts are supposed to break before the seatpost. I have not even heard of a Thomson failure before.


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## Jerk_Chicken (Oct 13, 2005)

That really sucks. Call them and they'll take care of you.


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## f3rg (Aug 29, 2007)

Wow, that sucks. Although, not everyone can brag about breaking a Thomson, so at least you have that much going for you.


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## sgtgeo (Feb 18, 2009)

I'm guessing they will be very concerned, send you a new one, and ask for the broken one for analysis


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## Jerk_Chicken (Oct 13, 2005)

Ever hit a garage?


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## Ricko (Jan 14, 2004)

Jerk_Chicken said:


> Ever hit a garage?


'Zakly what I was thinking:skep: .


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## apacherider (Mar 18, 2004)

Jerk_Chicken said:


> Ever hit a garage?


Nope. Don't even own a roof rack. Don't even own a garage.

Had to ride 18 miles home standing. That gets a little old after awhile. But not too bad. The weather was nice and I had the wind at my back.


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## Ricko (Jan 14, 2004)

apacherider said:


> Nope. Don't even own a roof rack. Don't even own a garage.
> 
> Had to ride 18 miles home standing. That gets a little old after awhile. But not too bad. The weather was nice and I had the wind at my back.


Wow, that is just nuts...looks like something absolutely catastrophic happened there. 18mi...no cell phone? I called the wife today to come and rescue me with the truck because I flatted on the road bike a 2nd time 15 miles from home, grrr.


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## RookieBeotch (Nov 2, 2008)

Is this even common for any kind of kind of seat post, including non name brands? Just thinking about the potential injury from taking that up the rear is disturbing.


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## Da Dook (Oct 6, 2007)

Now I've seen it all.


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## bensf (Mar 8, 2007)

Maybe it was a manufacturing defect that took 2k miles to finally break?


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## civil (Feb 13, 2008)

Any chance of getting a macro close up of the cross section on both ends? I'd love to see a close up of the damage.

I had a post fail on me on the trainer. But the funny part was that I was on the trainer b/c I had a broken collar bone so I couldn't use my arm/ride outside.

When the post broke, I collapsed to the floor banging my arm/shoulder into pretty much everything, that really hurt. But kinda funny now....


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## apacherider (Mar 18, 2004)

civil said:


> Any chance of getting a macro close up of the cross section on both ends? I'd love to see a close up of the damage.












That's about as good a photo as I can get with my crummy camera. I know nothing about metal or fatigue. The front side is the clean break side, the rear is the jagged side. From what I understand, the seatpost has an elliptical build to it with more material on the front/back rather than the sides. Does it look like the rear end lacks some material or is that just a result of the deforming when it broke?

In the photo below, see all the little teeny tiny fractures? They are on the rear facing side of the seat post. I don't know if they occured over time and I did not notice or if they occured as a result of the post at the moment it broke.


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## civil (Feb 13, 2008)

Well, I'll make some generalizations here, but here's a quick guess..

Judging by the pic (I can't really tell b/c I can't see enough detail), it looks like a crack may have initiated here (arrow) and slowly propagated outward towards the line. Every loading cycle would cause the crack to propagate further. (front side of post in Tension and back side in Compression, cracks propagated through tension side due to opening and closing of crack from loading cycles)

The surface looks smooth up until the line, indicating the area that the fatigue crack propagated through. 

To the right of the line, the remaining material wasn't strong enough to hold the stress and a shear failure (rough surface indicates this) occured, which would have deformed the rear end of the surface. The little wrinkles on the back of the post could be some straining due to the final shearing. 

Do I'll chalk it up to a fatigue failure due to some stress riser/imperfection.

*edit* Glad you were OK


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## 4 Jaw Chuck (Oct 2, 2004)

Geez that scares the crap out of me, and its a 31.6mm post too!

I guess I will be examining my 31.6mm straight post tonight real careful. From the lack of shiny rub points in the fracture zone it looks like it happened more or less all at once, sure looks thin on the relieved side.

Thanks for sharing with us, you may have saved someone elses rectum if they have a similar post issue. Glad you weren't hurt, it could have been real nasty. 

Kinda makes me rethink the weight savings from these seat posts, for the small amount of weight a straight gauge tube sure sounds safer.


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## Bikinfoolferlife (Feb 3, 2004)

Can't say I've seen a report of anything like the OP experienced FWIW. Everyone's gonna have a problem here and there. I think you can usually rely on Thomson's products more than many others in any case...


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## f3rg (Aug 29, 2007)

OP, how much do you weigh?




/hoping it's twice as much as I weigh


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## kapusta (Jan 17, 2004)

RookieBeotch said:


> Is this even common for any kind of kind of seat post, including non name brands? Just thinking about the potential injury from taking that up the rear is disturbing.


I've broken a post, and I don't think there is a huge danger of getting sodomized by the post. When it breaks you have the seat between your a$$ and the top of the post. Now, if you forget about it as you ride on, that's a different story.


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## Berkeley Mike (Jan 13, 2004)

*Thompson will want to see this.*

I'd send it to them for science alone. Now whether you want to see if they will cover it, that is another issue but I don't sense that you feel they are obliged


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## ash240 (Jun 2, 2007)

Also looks to me like a MFR issue. 
Just goes to show ALL parts need a regular check.

Oh, I would not have expected it to fail at that point. Should have been more flex further down the shaft. I would be very sure this was a fault from production.


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## desertking (Apr 9, 2009)

I ride nothing but Thomson, that blows my mind I thought they were indestructable. Glad to hear your ok, but 18 miles standing up...Your an ANIMAL!!!!


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## Spindelatron (Aug 15, 2006)

was anything sharp on your saddle bag rubbing the seatpost?


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## Cozy.Beehive (Apr 12, 2009)

*Thanks Apacherider*

Apacherider,

I noted a similar incident on a Thomson Elite seatpost on my blog. *Read it here.*

Seems like a good way to connect...

As you will see in my writeup and the attached pictures, I did the best I could to collect all relevant details from the rider as to how he used it. Given his information (and trusting it), I don't see how the bolting ears could have just snapped off like that.

In your case, again...I can't see how 2000 miles of riding will cause the post to crack at that spot.

What's your weight? And did you follow all installation instructions in the manual, like torque settings on the clamps? Did the post also take a fall anytime you remember, and like someone asked before me, do you remember having put anything sharp in your saddlebag that may have marked up the post? (I do not see how that can happen when something sharp is inside your bag but for the sake of information collection, let's have it all from you...)

Thanks...

Ron
Cozy Beehive Bike Blog


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## Jerk_Chicken (Oct 13, 2005)

> I noted a similar incident on a Thomson Elite seatpost on my blog. Read it here.


This failure is not similar.


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## Cozy.Beehive (Apr 12, 2009)

*Anodized Finish ?*



Jerk_Chicken said:


> This failure is not similar.


No, no one said its a similar failure. I said the incident is similar as in it involves a Thomson post.

Failures with Thomson are pretty rare given their reputation among cyclists for making strong components. But these two incidents occurred not very far apart from each other (both this year). Marketing materials from Thomson claim "over 40% on ultimate strength test than the strongest production seat posts on the market" and the presence of a unique 'bending fuse' to prevent catastrophic failure. *In my writeup*, we determined that this fuse could be nothing more but a fancy term for the cushion of safety achieved by the elliptical bore, specifically in the lateral sections of the post where it is thinnest, as opposed to the bolt ear locations which are thickest. Due to this, the sides of the post folds before the fore and aft sections having the bolt ears do, offering some degree of protection to the cyclist from a fall.

What could be interesting about the pictures provided by apacherider is that the ideas behind the "bend, not break" philosophy and the elliptical bore may be insignificant in reality...because as Civil pointed out here before, the crack originated on the thicker section (pointed by red arrow). But that's needs confirming through a fracture analysis.

Just one final thought. The black finish is beautiful. It is chemically polished and then anodized. *But my mind keeps asking whether this treatment makes the post any more susceptible for failure.* Jobst Brandt, mechanical engineer and author of "The Bicyle Wheel", didn't favor anodized rims, advising that when rims are anodized, a thin layer of porus, Al oxide is the result and the problem is that this oxide material is extremely hard but brittle. This makes the rim more susceptible to cracking and fatigue failure. This is actually a well known issue in materials circles. As Al bends elastically, the anodized surface cracks and the crack grows into the body of the Al. Anodized aluminum only worsens the fatigue limitations of Al. You can't bend anodized Al significantly without cracking it. The cracks that develop on the coating are stress risers and potential sources for fatigue failure in the substrate metal.

*Could the same be said for this seatpost, which also has an anodized finish? * My feeling is that anodizing is a bad choice for a part made to take bending.


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## Jerk_Chicken (Oct 13, 2005)

> No, no one said its a similar failure. I said the incident is similar as in it involves a Thomson post.
> 
> Failures with Thomson are pretty rare given their reputation among cyclists for making strong components. But these two incidents occurred not very far apart from each other (both this year). Marketing materials from Thomson claim "over 40% on ultimate strength test than the strongest production seat posts on the market" and the presence of a unique 'bending fuse' to prevent catastrophic failure. In my writeup, we determined that this fuse could be nothing more but a fancy term for the cushion of safety achieved by the elliptical bore, specifically in the lateral sections of the post where it is thinnest, as opposed to the bolt ear locations which are thickest. Due to this, the sides of the post folds before the fore and aft sections having the bolt ears do, offering some degree of protection to the cyclist from a fall.
> 
> ...


Your theory doesn't take into account that the moment Al is exposed to air, its surface oxidizes anyway. It's true, it's not controlled oxidation as Anodizing is, but there is a thin layer (thinner than anodization) that is actually protective.

You obviously haven't seen plenty of non-anodized parts bent that exhibit cracks like that.

Additionally, you're relating two things incorrectly. The cracks are on the back, and from shifting and bending as the last piece of the post was was still attached there. Some of your words here, and on your site, are looking like Alex Jones conspiracy theories, just jumping around for conclusions. And we get it. You're looking to get people to visit your site. Big deal. The post cracked, either from impact in a crash while riding, rider, anything, then the crack worked its way backwards and tore off. We can have a multitude of theories here, in and against the OP's favor, but there's also a history of Thomson's posts as having a low rate of failure and outlasting bikes.


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## Cozy.Beehive (Apr 12, 2009)

Jerk_Chicken said:


> Your theory doesn't take into account that the moment Al is exposed to air, its surface oxidizes anyway. It's true, it's not controlled oxidation as Anodizing is, but there is a thin layer (thinner than anodization) that is actually protective.
> 
> You obviously haven't seen plenty of non-anodized parts bent that exhibit cracks like that.
> 
> Additionally, you're relating two things incorrectly. The cracks are on the back, and from shifting and bending as the last piece of the post was was still attached there. Some of your words here, and on your site, are looking like Alex Jones conspiracy theories, just jumping around for conclusions. And we get it. You're looking to get people to visit your site. Big deal. The post cracked, either from impact in a crash while riding, rider, anything, then the crack worked its way backwards and tore off. We can have a multitude of theories here, in and against the OP's favor, but there's also a history of Thomson's posts as having a low rate of failure and outlasting bikes.


For a successful surface preparation before anodizing, an AL surface is chemically cleaned off all oxides and this is a basic requirement for the process. [See : AL and AL Alloys, ASM Handbook, Joseph Davis] I'm not sure what other intermediate oxide you're talking about. Please clarify.

Anodizing significantly decreases the fatigue strength of Al alloys. I based my judgment off that fact. I acknowledged the reputation of Thomson components already, as you can see. Infact, I'm a Thomson seatpost user and I wouldn't install one on my bike if I didn't think it was good. But again, no design is perfect. Not sure why you're so angry but you need to calm down. Again, if you actually read my blog post, you'd see that I made an effort to collect facts and discuss what might have caused the failure, since I understand a lot of folks may be using this product. You're quick to jump to narrow judgments.

Way to inform others about your knowledge though....:thumbsup:


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## Jerk_Chicken (Oct 13, 2005)

> For a successful surface preparation before anodizing, an AL surface is chemically cleaned off all oxides and this is a basic requirement for the process. [See : AL and AL Alloys, ASM Handbook, Joseph Davis] I'm not sure what other intermediate oxide you're talking about. Please clarify.





> Way to inform others about your knowledge though....


I'm displaying the contrast between the two parts of your post. You either don't read very well (comparing my post, and your first paragraph), or you don't want to read well and want to keep referring to your big book 'o knowledge.

And anger? Where do you gather that from? This is a message board and this is entertainment. You just don't seem to like when opinions counter yours because you have a book. You and Alex Jones should pair up.


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## Cozy.Beehive (Apr 12, 2009)

Jerk_Chicken said:


> I'm displaying the contrast between the two parts of your post. You either don't read very well (comparing my post, and your first paragraph), or you don't want to read well and want to keep referring to your big book 'o knowledge.
> 
> And anger? Where do you gather that from? This is a message board and this is entertainment. You just don't seem to like when opinions counter yours because you have a book. You and Alex Jones should pair up.


Ok I will pair up if I wish.  Tell me something. What oxide were you talking about? Thought you were going to reply to that.  I acknowledge my mistake... I meant to say the wall thickness of the post body are thinnest at the sides, when you look from the bottom. It is more thicker to the front and rear.


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## Jerk_Chicken (Oct 13, 2005)

The answer is in post 26.


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## Cozy.Beehive (Apr 12, 2009)

Jerk_Chicken said:


> The answer is in post 26.


I did see that and replied right away that before anodizing, the industry standard is to chemically clean the surface off any pre-existing oxides to ensure a good anodized finish through electrolysis, which you didn't bother replying to.


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## Jerk_Chicken (Oct 13, 2005)

> I did see that and replied right away that before anodizing, the industry standard is to chemically clean the surface off any pre-existing oxides to ensure a good anodized finish through electrolysis, which you didn't bother replying to.


Then I can't help you.

Also noted is altering your posts after I reply to them.


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## Cozy.Beehive (Apr 12, 2009)

apacherider said:


> I'm OK, which is the main thing. Seriously, if I had not been riding on smooth concrete, this would have been a compete disaster. Added help was that I have a small Cannondale seatbag for a spare tube under my seat with small velcro loop that goes around the post in addition to the seat rails. That's the only thing that saved me from an aluminun colonoscopy. I have 5 Thomson seatposts and never had an issue with any of them till today. Across those posts I have over 100,000 care free miles. Owned this particular post 10 months and about 2000 miles. It's a Thomson Setback 31.6 410mm I have been using in Cannondale Caffeine framesets. The post has never been dropped, wrecked, knock over or even put in a repair stand.
> 
> Frankly I did not think this was possible because I read that the bolts are supposed to break before the seatpost. I have not even heard of a Thomson failure before.


Apache, no where did I come across a statement that their bolts are supposed to break before the seatpost. I would expect something like this to be counterproductive to safety. If the bolts break, the saddle comes off and there goes the rider.

From *marketing materials*, this is said : *"Under severe impact the Thomson seatpost would bend slightly and allows the rider to come to a safe stop or finish the ride. The ride could continue."*

Putting this alongside what you actually experienced, things do not add up.


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## apacherider (Mar 18, 2004)

Cozy.Beehive said:


> Apacherider,
> 
> I noted a similar incident on a Thomson Elite seatpost on my blog. *Read it here.*
> 
> ...


Read your link. Wow! You really got in depth there.

To answer your questions, I weigh anywhere from 190-200lbs depending on the time of year. I only ride XC, mostly fire roads, XC trails and pavement. That post has never been in a wreck, collision, never hit a tree, post or pole. Never even been in a repair stand.

Installation instructions were followed to the letter. Not so much for the seat post's sake but because I have an expensive Fizik saddle and do not want to bugger it up. Like I said in my post above, it is a 31.6mm 410, which fits the Cannondale Caffeine. I was using it in a 2009 Cannondale 29er 2, that I have only owned since early March. I have been over that bike with a fine tooth comb a dozen times since I bought it. Here is the top tube/seattube junction:










Brand new bike for the most part. Maybe 800 miles on the frame, only 50 of which were on dirt.

Here are a few more photos with the hardware removed. Gives one a better sense of where it broke:

Back:








Front:









Also included a photo of the saddlebag I use, since you asked about it.









Must just be a complete fluke that it broke. Like I said, I have used Thomson seatposts for a decade, 100,000 miles worth. I'm one of their biggest fans. Just left me scratching my head as to how it broke. I average about 800-1000 miles a month riding, so this was a very low mileage part for me.

I'll get in contact with them on Monday and see about a warranty replacement. Still have the cloth bag it came in too!


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## kapusta (Jan 17, 2004)

This is not that big of a mystery. Things break. Even high quality things that almost _never _break _sometimes _break. It's like the lottery: You can pretty much count on NOT winning with near certainty, and it is a huge surprise when you do, but it's not "how could this possibly happen?"

I would say that after 100,000 miles, it is not that outlandish that you could see some unlikely event, such as one of these failing. That's what, 5,000 20-miles rides? A 20 mile ride _every _day for almost 14 years?

After 2,000 miles (100 20-mile rides, or roughly three 20-milers per week for the ten months you've had it) I find it unlikely that you can say for certain that there was never any damage that happened to the post, or some blow that could have started the crack. Not saying you did it, but I can't see how that could _possibly _be ruled out.


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## apacherider (Mar 18, 2004)

kapusta said:


> I find it unlikely that you can say for certain that there was never any damage that happened to the post, or some blow that could have started the crack. Not saying you did it, but I can't see how that could _possibly _be ruled out.


Just to rule that out, I don't have so much as a scratch of any kind on my saddle. It's a Fizik with 5000 miles on it. Like I have said, no damage to the seatpost. Besides, that failure is so far up underneath the saddle nose(on the front) and basically under the rails(on the rear), that I don't think anything could contact it. It. Just. Broke.


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## civil (Feb 13, 2008)

kapusta said:


> This is not that big of a mystery. Things break.


Very true, but the question is why. Riding mishap? Installation error? Manufacturing defect?



kapusta said:


> I find it unlikely that you can say for certain that there was never any damage that happened to the post, or some blow that could have started the crack. Not saying you did it, but I can't see how that could _possibly _be ruled out.


While it may not be certain, it's highly unlikely that something would have hit that area while riding. It's very high on the post, almost hidden by the bolt, and shielded by his legs. For an item small enough to hit that exact spot, with enough force to damage the post, while dodging all the obstacles in the way is pretty low on the probability scale. Not impossible, but unlikely.

Probably not an installation error, that would have failed the post at the seat-tube clamp or post bolt.

A much more probable solution was that there was some kind of stress riser there from the manufacturing process.

Or it was damaged in shipping and handling. That being said, for it not to be noticed during installation would mean a very small damaged area which would require a very large force by a very small object. Possibly your room-mate with a hammer and nail punch. Do you have any enemies that would benefit from your passing?


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## kapusta (Jan 17, 2004)

civil said:


> Possibly your room-mate with a hammer and nail punch.


I was thinking pissed off ex.


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## RookieBeotch (Nov 2, 2008)

Regardless, I still want a Thomson post for my bike.


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## civil (Feb 13, 2008)

kapusta said:


> I was thinking pissed off ex.


Even more likely



RookieBeotch said:


> Regardless, I still want a Thomson post for my bike.


PM apacherider, I think he has one for cheap.


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## Cozy.Beehive (Apr 12, 2009)

apacherider said:


> Read your link. Wow! You really got in depth there.
> 
> To answer your questions, I weigh anywhere from 190-200lbs depending on the time of year. I only ride XC, mostly fire roads, XC trails and pavement. That post has never been in a wreck, collision, never hit a tree, post or pole. Never even been in a repair stand.
> 
> ...


Sounds good. Let us know how the conversation goes. The last time I tried emailing them on this topic, their email wasn't even working. I figured concerns about the reliability of the seatpost must have flooded their inbox, but in reality...a lady who worked there told me that they were having some work done to their telephone network. Either way, if you're going to call them based on the number on their website, its going to go to a call center...the people who work there may have limited knowledge about technical issues. Just a heads up.


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## sherijumper (Feb 19, 2007)

This has been an interesting read , I run thomson posts on two of my bikes and no problems thus far ( like 99 % of us) . As Kapusta said " it`s like winning the lottery" I think that is a pretty good point . Thomson posts , stems are some of the strongest in the industry . I think this thread is just another good reason to inspect our equipment when mantaining it . I know you won`t catch every hairline crack, but you never know what you might find .


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## CdaleTony (Jun 21, 2005)

Jerk_Chicken said:


> *Your theory doesn't take into account that the moment Al is exposed to air, its surface oxidizes anyway.* It's true, it's not controlled oxidation as Anodizing is, but there is a thin layer (thinner than anodization) that is actually protective.
> 
> You obviously haven't seen plenty of non-anodized parts bent that exhibit cracks like that.
> 
> Additionally, you're relating two things incorrectly. The cracks are on the back, and from shifting and bending as the last piece of the post was was still attached there. Some of your words here, and on your site, are looking like Alex Jones conspiracy theories, just jumping around for conclusions. And we get it. You're looking to get people to visit your site. Big deal. The post cracked, either from impact in a crash while riding, rider, anything, then the crack worked its way backwards and tore off. We can have a multitude of theories here, in and against the OP's favor, but there's also a history of Thomson's posts as having a low rate of failure and outlasting bikes.


The answer is in post 26..I looked, and there it is! 
I think JC is talking about a non-anodized post becoming "anodized" (IE oxidized) anyway when exposed to the elements. Thereby nullifying to some extent the claim that anodizing is worse than non anodized!
By Jove!
CDT :thumbsup:


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## sdf1968 (Mar 7, 2007)

I had a seatpost break once when I first started to ride. It was not a Thomson so I am not as talented as apacherider.  I was on a really fast downhill and I just jumped off a small lip and when I landed all I heard was PING and I was on the ground looking at the sky. Had a round bruise in the middle of my chest so I think there is less chance of rectal damage and more chance of torso damage. I had to ride 7 miles back standing up and I thought that was bad....18 miles!:eekster:


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## wormvine (Oct 27, 2005)

I guess we all should get thermal cams then. Easy to spot a crack with a thermal cam!


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## wormvine (Oct 27, 2005)

CdaleTony said:


> The answer is in post 26..I looked, and there it is!
> I think JC is talking about a non-anodized post becoming "anodized" (IE oxidized) anyway when exposed to the elements. Thereby nullifying to some extent the claim that anodizing is worse than non anodized!
> By Jove!
> CDT :thumbsup:


How does it nullify it? Just cause nicks of exposed aluminum oxidized slightly doesn't mean it has the same affect that a large scale chemical anodization does. It raises a question that needs to be researched but far from nullifies the original statement.


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## TNC (Jan 21, 2004)

Yeah, this has been interesting. Thomson makes some nice, tough seatposts, but as already stated, nothing is indestructible. The only Thomson seatpost issue I've ever seen is the "crimping" that can occur, usually in cases of overtighening the post collar at the seat tube. Seatposts shouldn't be overtightened, but a Thomson is one such post that can develop a "waist" at the point of normal seating height. Not that the Thomson is the only one that can have this occur. Even then, however, I've never seen one break at that "waisted" spot on the post. Usually the only evidence of this is when the post won't stay put exactly where you tighten it.


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## themanmonkey (Nov 1, 2005)

OK from an industry standpoint Thompson stuff is great and has one of the best reps around, but they're far from perfect. I've installed a few hundred posts and stems and seen a good number of broken and poorly-machined parts. Of course I don't know of a post maker I haven't seen break. Parts breakages are part of the game and it's so much better than 10-20 years ago. I generally tell folks that if you have a lightweight post, stem, or bar think about replacing them after 10,000 miles.

Personally I have a Control Tech, a couple American Classic, and various Campy posts that are well over a decade old and 10,000 miles was a long time ago on all of them. I also have a superlight ti McMahon post that supposedly "always broke" still running strong. I know I'm on borrowed time on each of these posts and I just keep that in mind when I ride. It's not about if a part will break, it's about when it'll break.

Again, Thompson parts are some of the most reliable parts in the industry, but they won't last forever.


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## longcat (Apr 24, 2008)

Its a brittle fracture, I guess all these common aluminum alloys breaks brittle more or less. What could have caused it? I dont know, anything from bad hair day to alloying % being out of specs to microscopic pores to bad heat treatment or overheating while being machined etc etc etc probably 1000s of possible resons for this failure. Could be anything really


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## civil (Feb 13, 2008)

longcat said:


> Its a brittle fracture, .......... Could be anything really


Did you actually read any of the posts?

There are a couple of educated guesses with some valid reasoning behind them which point to a specific answer.


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## longcat (Apr 24, 2008)

civil said:


> Did you actually read any of the posts?


Yes, all of them.


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## civil (Feb 13, 2008)

longcat said:


> Yes, all of them.


Your previous post begs to differ.



longcat said:


> etc etc etc probably 1000s of possible resons for this failure. Could be anything really


The damaged x-section gives plenty of info to narrow it down to a few things.


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## longcat (Apr 24, 2008)

civil said:


> Your previous post begs to differ.
> 
> The damaged x-section gives plenty of info to narrow it down to a few things.


Does it? Could you elaborate?


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## civil (Feb 13, 2008)

longcat said:


> Does it?


Absolutely.



longcat said:


> Could you elaborate?


See post #14 and #26 for some opinions and reasoning.

Are you sure you read all the posts?


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## themanmonkey (Nov 1, 2005)

*civil* just because there are some people posting good speculation, and it is only speculation, there can be a thousand other reasons the part fails. No one on this thread has done any kind of xray or dye penetration tests, or even FEA. We're all a bunch of folks on the internet and if you hadn't heard 'everybody on the internet is an expert.'


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## civil (Feb 13, 2008)

themanmonkey said:


> *civil* just because there are some people posting good speculation, '


There's wild speculation, and there's speculation with reason.

I have seen 3 reasonable guesses with some evidence that make it seem plausible.

I took note of the previous poster's comment b/c it was obvious that he didn't read the thread at all and gave some wild speculation and I called him on that. No big deal, I skim through threads all the time an miss details.

If you read my post, which I'm sure you did, you will see that I state the limitations of my interpretation.



themanmonkey said:


> there can be a thousand other reasons the part fails.


Yes there can, but looking at the evidence can help point to a probable cause, and reduce the it from thousands to several.



themanmonkey said:


> or even FEA.


Funny this topic came up actually, here is a project I did just 2 days ago on my Thomson setback post. Is it correct? Who knows......probably not given my crap Abaqus skills  . But it was fun.


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## kapusta (Jan 17, 2004)

civil said:


> Funny this topic came up actually, here is a project I did just 2 days ago on my Thomson setback post. Is it correct? Who knows......probably not given my crap Abaqus skills  . But it was fun.


Nice paint job:thumbsup:


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## civil (Feb 13, 2008)

Thanks, I was worried it was going to be too blingy


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## apacherider (Mar 18, 2004)

If you need any proof that Thomson is a great company, check this out. I sent them an email late this afternoon, outlining my seatpost issue. Thought nothing of it, considering it's Easter Sunday afternoon. Probably hear back later in the week. Boy was I shocked when someone sent me an email almost right back regarding replacement of the post! On Easter Sunday! 

Can you believe that?

Great companies do business this way.


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## steadite (Jan 13, 2007)

civil said:


> Funny this topic came up actually, here is a project I did just 2 days ago on my Thomson setback post. Is it correct? Who knows......probably not given my crap Abaqus skills  . But it was fun.


But doesn't include the radius where the fatigue occurred....

Your analysis of the fracture (post #14) is correct...only thing I would add is that I see multiple fatigue origins on the tensile side of the post (there are "ratchet" marks along about a 5 mm length) rather than just one initiation site. This argues against the discreet material defect theory and for the theory of "just plain exceeded the fatigue strength of the material".


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## Jerk_Chicken (Oct 13, 2005)

CdaleTony said:


> The answer is in post 26..I looked, and there it is!
> I think JC is talking about a non-anodized post becoming "anodized" (IE oxidized) anyway when exposed to the elements. Thereby nullifying to some extent the claim that anodizing is worse than non anodized!
> By Jove!
> CDT :thumbsup:


Sir, unless you come to this thread armed with Tobin's Spirit Guide, you are not welcome here :thumbsup:


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## themanmonkey (Nov 1, 2005)

apacherider said:


> Can you believe that?


Yep, that's the reason they're one of the most respected names making bike parts. It's also is the reason the post is one of the best reviewed parts over in the reviews section.


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## civil (Feb 13, 2008)

steadite said:


> But doesn't include the radius where the fatigue occurred....


Yeah, I should have clarified, that was just for an unrelated project I was doing on my own. I only posted it b/c thought it was funny how I had just recently finished that and this thread came up. They are only related by the product name....



steadite said:


> ........only thing I would add is that I see multiple fatigue origins..........This argues against the discreet material defect theory and for the theory of "just plain exceeded the fatigue strength of the material".


I can't see the ratchet marks very well, my eyes are not as good as they used to be so I'll take your word for it (a high quality pic of that area would help me). However, if it was the case of just exceeding the fatigue strength of the material, does it surprise you that it occurred at such a low cycle count (used for ~ 2000 miles)?


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## Jim311 (Feb 7, 2006)

I visited the Thomson factory in Georgia once on a road trip. In fact, the late Mr. Thomson himself was there, on a Sunday! I came to ride their trail network that they had behind the factory just to break up the monotony of a road trip, but ended up touring the factory and checking out some new parts they had and chatting with them for a bit. They are a super cool company and very nice guys. When I saw this thread I was sure they would take care of you regardless of what the problem was. They charge a premium but the service and quality you get justify it! That said, nothing is 100% and even good parts break or have defects once in a while.


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## steadite (Jan 13, 2007)

civil said:


> if it was the case of just exceeding the fatigue strength of the material, does it surprise you that it occurred at such a low cycle count (used for ~ 2000 miles)?


Well, the whole thing flies in the face of everyone else's experience: the fact that these posts don't generally break. With trail bumps and whatnot, I suppose it's reasonable that a lot of cycles could be racked up in 2000 miles (100 bumps per mile would be 200k cycles).

Who knows...maybe the material wasn't aged right (low hardness)...maybe some machining damage (surface deformation or tool marks) or anodizing pits that we can't see...they need a real failure analysis...one with microscopes involved!!

I do agree with the statement that anodizing is bad for aluminum fatigue---that's a known thing. it's done successfully on bike components all the time tho. The natural oxidation that occurs in air is not nearly as thick as the anodized layer.

To the OP...don't rub the fractures together and wrap them in paper towel separately in ziplock bags b4 sending back. hard for their lab to analyze the fracture if they're all rubbed up.


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## kntr (Jan 25, 2004)

Those are the first 2 I have ever heard or seen break.


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## xcguy (Apr 18, 2004)

Yes, I did read every reply but I didn't see anything mentioned about: were all the OPs other Thomson seatposts "setback" posts and...could the potential for failure in a Thomson seatpost be possibly higher _because_ it is a setback? I have four Thomson straight seatposts working now with two more in a box.


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## apacherider (Mar 18, 2004)

xcguy said:


> Yes, I did read every reply but I didn't see anything mentioned about: were all the OPs other Thomson seatposts "setback" posts and...could the potential for failure in a Thomson seatpost be possibly higher _because_ it is a setback? I have four Thomson straight seatposts working now with two more in a box.


All my other posts are traditional straight seatposts. Don't think that really matters though since the failure occured up near the top. If you try to visualize it, I don't see how the bend further down the seatpost could be a cause.


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## labeda14 (Feb 8, 2007)

Just figured I would throw in my two pennies here...I have four bikes with Thomson posts and stems. The oldest one is on a full sus. cross bike that is nearly ten years old. In 2004 the face plate developed a crack. I called up Thomson and they sent me a new one, no questions asked. About three weeks ago, my brother was riding the above mentioned bike and as he got to the top of a steep loose gravel climb, he said "I think something is wrong with the handlebars" Upon further inspection the bars had rotated. I straightened the bars and went to tighten the steerer tube clamp bolts and noticed they were very loose. The bike does not get much use these days and spent most of the winter in my unheated garage. I did not think much of and we finished the ride (probably another hour or so). Well the following weekend I grabbed the bike to go for a ride and noticed a crack from top to bottom on the back of the steerer tube clamp. It is a black stem and there is no way I would have missed that on the trail...perhaps I over tightend the bolts, perhaps there already was a hairline crack...who know...I called up Thomson and they said to send it back and they would send me a new one. The stem got here about a week later, no questions asked. THEY REPLACED A PART NEARLY 10 YEARS OLD!! THOMSON ROCKS!

Ok, well I have rambled enough...glad to hear you are ok and that they took care of you too.

Cheers,

Doug


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## apacherider (Mar 18, 2004)

steadite said:


> To the OP...don't rub the fractures together and wrap them in paper towel separately in ziplock bags b4 sending back. hard for their lab to analyze the fracture if they're all rubbed up.


I already mailed it before I read your post.The head of the post I wrapped in a paper towel, then stuck it in the Thomson bag with the rest of the post, inside a bubble mailer.


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## xcguy (Apr 18, 2004)

apacherider said:


> All my other posts are traditional straight seatposts. Don't think that really matters though since the failure occured up near the top. If you try to visualize it, I don't see how the bend further down the seatpost could be a cause.


Trust me, I'm no engineer but every time I look at a "setback" or "layback" seatpost it seems to me that there would be stresses applied totally unlike with a straight post along its entire length.


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## snowdrifter (Aug 2, 2006)

apacherider said:


> That post has never been in a wreck, collision, never hit a tree, post or pole. Never even been in a repair stand


You ride 2000 miles without crashing once? That's insane.


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## apacherider (Mar 18, 2004)

snowdrifter said:


> You ride 2000 miles without crashing once? That's insane.


Nope. No wrecks. No falling down. Nearly all my riding with that seatpost was on pavement. Some fireroads, some singletrack. I spend more than half my time in Dallas, the balance in Taos, NM. The Cannondales that I ride with this particular seatpost have spent over 90% of it's time in Dallas rather than Taos.

Plus, much of last year (spring and summer) I was recovering from a monster huge car accident I was in, that occured in October 2007. Car drivers fault, ruined a road bike, I got a nice check. Broken ribs, messed up tailbone, shoulder etc. So....all last spring and summer I would ride everyday, but just on pavement. Falling and wreckin' was verboten! Pretty incredible how careful you can be while riding if you are scared of re-breaking a rib.


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## cruso414 (Aug 19, 2004)

since it was in a cannondale, it looks like it heard that cannondale's will now be made in taiwan and it's head exploded.


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## crashtestdummy (Jun 18, 2005)

Thomson setback posts are machined and then bent to the setback position. You would think if there were any fatigue points they would be caused by this. This doesn't appear to be the case in *apacherider's* situation though.


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## xcguy (Apr 18, 2004)

crashtestdummy said:


> Thomson setback posts are machined and then bent to the setback position. You would think if there were any fatigue points they would be caused by this. This doesn't appear to be the case in *apacherider's* situation though.


I'm not talking about "induced" fatigue points caused by the actual bending/manufacturing process. I'm talking about the funky forces caused by the saddle not being in the same relative position as on a straight post (maybe even exacerbated by the saddle being back on the rails).

Again, I'm no engineer but it seems clear to me that it just isn't the same situation all around, setback vs straight. Doesn't it seem odd that the OP has a history of Thomson seatposts and the only one he's broken was a setback?

We all know Thomson makes the best seatposts but I wonder if their parameters for a setback are as stringent as on their straight ones? You know, like they might be saying "setbacks aren't the best way to re-position a rider (due to long thighs or too-short a top tube or whatever) but if the rider really wants one we'll give him one, even though it's not going to be as strong as our straight seatposts". Maybe. Kind of like doing curls with your elbows out in front of you and not at your sides.


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## Dazed (Feb 7, 2004)

Setback seatposts used to be used much, much more than inline posts, so I don't really think so.


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## apacherider (Mar 18, 2004)

xcguy said:


> I'm not talking about "induced" fatigue points caused by the actual bending/manufacturing process. I'm talking about the funky forces caused by the saddle not being in the same relative position as on a straight post (maybe even exacerbated by the saddle being back on the rails).
> 
> Again, I'm no engineer but it seems clear to me that it just isn't the same situation all around, setback vs straight. Doesn't it seem odd that the OP has a history of Thomson seatposts and the only one he's broken was a setback?
> 
> We all know Thomson makes the best seatposts but I wonder if their parameters for a setback are as stringent as on their straight ones? You know, like they might be saying "setbacks aren't the best way to re-position a rider (due to long thighs or too-short a top tube or whatever) but if the rider really wants one we'll give him one, even though it's not going to be as strong as our straight seatposts". Maybe. Kind of like doing curls with your elbows out in front of you and not at your sides.


The seat on that particular seatpost was pretty far back on the rails. Meaning in addition to having the setback post, I had the seat moved back a little further back beyond the neutral position on the rails. If that makes sense. The result was that the post was clamped on the forward 1/3 of the usable rail area. Not sure if that made a difference or not but it would have given a little bit more leverage on the top end of the post. Although I bet my saddle rails would have bent before the seatpost did.


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## sand101 (Nov 30, 2008)

steadite said:


> But doesn't include the radius where the fatigue occurred....
> 
> Your analysis of the fracture (post #14) is correct...only thing I would add is that I see multiple fatigue origins on the tensile side of the post (there are "ratchet" marks along about a 5 mm length) rather than just one initiation site. This argues against the discreet material defect theory and for the theory of "just plain exceeded the fatigue strength of the material".


This is correct - there is a large process zone there where the material fatigued. Only thing wrong in that post is the assertion that there was subritical crack growth through 1/2 of the circumference - you can see the crack origin pretty clearly and the crack would have gone to a critical flaw size well before that. T6 aluminum is a 40ksi material and pretty much linear to very close to failure. The rider must have been putting some serious weight down on the nose of his saddle (many times).

I'm surprised to see such a process zone in T6.


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## Cozy.Beehive (Apr 12, 2009)

apacherider said:


> Nope. No wrecks. No falling down. Nearly all my riding with that seatpost was on pavement. Some fireroads, some singletrack. I spend more than half my time in Dallas, the balance in Taos, NM. The Cannondales that I ride with this particular seatpost have spent over 90% of it's time in Dallas rather than Taos.
> 
> Plus, much of last year (spring and summer) I was recovering from a monster huge car accident I was in, that occured in October 2007. Car drivers fault, ruined a road bike, I got a nice check. Broken ribs, messed up tailbone, shoulder etc. So....all last spring and summer I would ride everyday, but just on pavement. Falling and wreckin' was verboten! Pretty incredible how careful you can be while riding if you are scared of re-breaking a rib.


Apache,

This is interesting because if this is true, you're essentially telling us that you didn't abuse it. However, what I was interested in knowing was whether you used a torque wrench to tighten the bolts. According to Thomson, a majority of failures like these happen due to over torquing. You're really lucky to escape without injury. Let us know your thoughts on this.

-Ron


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## apacherider (Mar 18, 2004)

Cozy.Beehive said:


> Apache,
> 
> This is interesting because if this is true, you're essentially telling us that you didn't abuse it. However, what I was interested in knowing was whether you used a torque wrench to tighten the bolts. According to Thomson, a majority of failures like these happen due to over torquing. You're really lucky to escape without injury. Let us know your thoughts on this.
> 
> -Ron


Yes. I used a torque wrench. I use a torque wrench on virtually all my bike parts. In the past, back when I used square taper bottom brackets, using a torque wrench was essential. I have kept that practice up over the years. I'm 100% positive a torque wrench was used on this particular seatpost. Matter of fact, if you look at one of the bolts, you can see where I kind of buggered up the head of one of them with the torque wrench as it slipped off.

Besides, where the seatpost broke is far removed from the area where the bolts affix to the seatpost itself. I do not see how there could be any correlation.

Like I have said before, I'm a big fan of Thomson seatposts. I have them on many of my bikes. I would never consider using anything but them. I have gone through and carefully looked at all my other Thomsons, checked for cracks and also checked the torque on the bolts. Each were crack free and right on the money.


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## Barkleyfan (Jul 26, 2008)

I wouldn't worry about it Apache. Manufacturers buy metal in bulk, and then process it into a final product. Sometimes the metal has defects. Thompson is pretty good at detecting flawed material, and their machining techniques are top-notch. I'm no expert metalurgist, but I've got a little experience from the machinists end. Looks like there was a flaw that slowly expanded to failure. It happens. See if Thompson is willing to warranty the post, and call it a day.


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## Cozy.Beehive (Apr 12, 2009)

Barkleyfan said:


> I wouldn't worry about it Apache. Manufacturers buy metal in bulk, and then process it into a final product. Sometimes the metal has defects. Thompson is pretty good at detecting flawed material, and their machining techniques are top-notch. I'm no expert metalurgist, but I've got a little experience from the machinists end. Looks like there was a flaw that slowly expanded to failure. It happens. See if Thompson is willing to warranty the post, and call it a day.


You seem to be inventing your own little story here. I have been in talks with Thomson and so far, no mention was made of defective material. They absolutely stand by their products. It seems you know more about their material than they do.


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## wormvine (Oct 27, 2005)

Cozy.Beehive said:


> You seem to be inventing your own little story here. _I have been in talks with Thomson _and so far, no mention was made of defective material. They absolutely stand by their products. It seems you know more about their material than they do.


I think you meant to say you work for Thomson. Why on earth would any manufacturer mention to a customer that there was a flaw in their product materials? You do not need to admit fault to stand by your product. You just send out a replacement item or fix it if possible.


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## Cozy.Beehive (Apr 12, 2009)

wormvine said:


> I think you meant to say you work for Thomson. Why on earth would any manufacturer mention to a customer that there was a flaw in their product materials? You do not need to admit fault to stand by your product. You just send out a replacement item or fix it if possible.


You bring together some of your "little" machinist experience working for some company in the past to make generalizations about Thomson and their QC. How come you know that their material is defective for certain? Can you spell F-L-U-F-F?


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## Barkleyfan (Jul 26, 2008)

Cozy.Beehive said:


> You seem to be inventing your own little story here. I have been in talks with Thomson and so far, no mention was made of defective material. They absolutely stand by their products. It seems you know more about their material than they do.


LMFAO Vested interest? Seriously, WTF do you care about Apaches resolution? If you wanna pretend Thompson does UT testing on every inch of every peice they put out, pretend away. Having done production level QA, I know it's highly unlikely. Especially for the price. Sometimes flaws get through.It's not the end of the world.


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## Cozy.Beehive (Apr 12, 2009)

Sorry, you lose. Your attitude is the traditional way of thinking and it doesn't help. All to often its easy to say 'things break, let's move on'. If this was someone in your family getting hurt, you would probably change your outlook. Your claims about Thomson's QC is some conjecture at best. I'm also not sure what caused you to "LMFAO". All this is a circus act to you.


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## mullet dew (Jun 4, 2008)

Cozy.Beehive has at last exposed the truth, 2 Thomson seatposts, of the thousands upon thousands of posts sold, have broke. The sky is officially falling. Thomson is not perfect, the Apocalypse has begun.

PS anyone wanna trade their Sette for my 30.9x367 Thomson? I no longer feel safe.


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## adam728 (Jan 25, 2006)

Cozy.Beehive said:


> Sorry, you lose. Your attitude is the traditional way of thinking and it doesn't help. All to often its easy to say 'things break, let's move on'. If this was someone in your family getting hurt, you would probably change your outlook. Your claims about Thomson's QC is some conjecture at best. I'm also not sure what caused you to "LMFAO". All this is a circus act to you.


If we are allowed a 0% failure rate then every manufacturer in the world would shut their doors. No product is perfect, and no amount of testing is going to ensure that it is. The idea is to design it right, build it right, and have enough QC checks in place to try and get as close to that 100% perfect as you possibly can.

You want a product with a 0% chance for failure? Go pick up rocks and sell them as paper weights. Of course, then someone will drop one on a family member's toe and sue you anyway.


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## MarcusSommers (Sep 11, 2008)

To the op, glad you are okay. I consider Thomson posts and stems to be the best in the industry, and it sounds like you would agree. I would let them have it for testing, but request it back, because you will need proof that you broke one.


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## Cozy.Beehive (Apr 12, 2009)

adam728 said:


> If we are allowed a 0% failure rate then every manufacturer in the world would shut their doors. No product is perfect, and no amount of testing is going to ensure that it is. The idea is to design it right, build it right, and have enough QC checks in place to try and get as close to that 100% perfect as you possibly can.
> 
> You want a product with a 0% chance for failure? Go pick up rocks and sell them as paper weights. Of course, then someone will drop one on a family member's toe and sue you anyway.


I didn't propose anywhere that the manufacturer in question has 0% failure rate.


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## Bikinfoolferlife (Feb 3, 2004)

Cozy.Beehive said:


> I didn't propose anywhere that the manufacturer in question has 0% failure rate.


No, but you're pushing an issue, that not only isn't yours, but one that is one of the least to be concerned with in the whole of the mountain bike component world...you have more of the flavor of a lawyer looking for that very small exception on which to base a rule...


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## apacherider (Mar 18, 2004)

MarcusSommers said:


> To the op, glad you are okay. I consider Thomson posts and stems to be the best in the industry, and it sounds like you would agree. I would let them have it for testing, but request it back, because you will need proof that you broke one.


It hit their mailbox in Georgia, last friday. Should be getting a new one back any day now. No problems! Only reason I started the thread was due to the rarity of a failure. Had it been some other random part I would not even have mentioned it, much less started a thread. I hope you guys now include periodic checks of all your parts for cracks. I personally don't know when this crack formed or how long I'd been riding with it this way. Think I mentioned before, that I'm rather anal about bike maintenance, so this crack was a complete shock to me.


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## Cozy.Beehive (Apr 12, 2009)

Please read on the engineering issues and analysis of the broken seatpost in question. Here's the results of my latest interview with a Thomson insider. *http://cozybeehive.blogspot.com/2009/04/broken-thomson-seatposts-overtightening.html
*

Apache, you're copied to this as well. Thomson says there is no doubt in their minds that you overtightened this seat post, as much as 2.5 to 3 times the recommended values (read link above). Again, that's not me saying it. I also have a vested interest in this matter only so far as to get objective information.


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## wormvine (Oct 27, 2005)

What a fukin joke?


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## Cozy.Beehive (Apr 12, 2009)

That was quick. Turns out you didn't even read the link I posted.


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## Jerk_Chicken (Oct 13, 2005)

Cozy.Beehive said:


> Please read on the engineering issues and analysis of the broken seatpost in question. Here's the results of my latest interview with a Thomson insider. *http://cozybeehive.blogspot.com/2009/04/broken-thomson-seatposts-overtightening.html
> *
> 
> Apache, you're copied to this as well. Thomson says there is no doubt in their minds that you overtightened this seat post, as much as 2.5 to 3 times the recommended values (read link above). Again, that's not me saying it. I also have a vested interest in this matter only so far as to get objective information.


Did you even ask anyone's permission to do such a thing?


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## ash240 (Jun 2, 2007)

Cozy.Beehive said:


> Please read on the engineering issues and analysis of the broken seatpost in question. Here's the results of my latest interview with a Thomson insider. *http://cozybeehive.blogspot.com/2009/04/broken-thomson-seatposts-overtightening.html
> *
> 
> Apache, you're copied to this as well. Thomson says there is no doubt in their minds that you overtightened this seat post, as much as 2.5 to 3 times the recommended values (read link above). Again, that's not me saying it. I also have a vested interest in this matter only so far as to get objective information.


What else was said? We only have limited quotes and nothing you have put up there is "proof" of the claims being made. Having looked at the pics I have a hard time believing that line blaming the customer. A REALLY hard time thinking anyone with any training would see that failure and fall for that line. Your own "information" even points to holes in the lines you were fed blaming the customer.

"Dave : "I also observed that the bolt heads are distorted. The bolts are grade 12.8. We know how much torque it requires to distort the bolt heads, and it is in excess of 125 inch pounds. ....."

THAT is ABSOLUTELY idiotic. You are a fool for putting such a stupid comment online and thinking it supports your "case".

In my opinion, I wouldn't "trust" any "engineer" who acted like you have been. 
No supporting evidence of your claims, reproducing claims made by others (who may or may not be qualified and ARE not independent) and misrepresenting this as being an open minded and valid investigation of an issue.

Do you have permission to use the photos?


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## Cozy.Beehive (Apr 12, 2009)

ash240 said:


> What else was said? We only have limited quotes and nothing you have put up there is "proof" of the claims being made. Having looked at the pics I have a hard time believing that line blaming the customer. A REALLY hard time thinking anyone with any training would see that failure and fall for that line. Your own "information" even points to holes in the lines you were fed blaming the customer.
> 
> "Dave : "I also observed that the bolt heads are distorted. The bolts are grade 12.8. We know how much torque it requires to distort the bolt heads, and it is in excess of 125 inch pounds. ....."
> 
> ...


Sorry that you didn't like the outcome of this case. I'm not supporting either one, just informing people of what the user did, and what Thomson says. Be known, that if you live in Georgia, and contact Dave Parett, he'll be more than happy to lead to on a factory tour to show you how everything is done. Maybe you can argue with him there? In the end, I obviously see contradications. Apache says he used a torque wrench, like he always did...Thomson claims he didn't and that their observation of the broken specimen shows there's only limited number of ways that seatpost could break. My job is to inform people that eitherway, you cannot afford to overlook the tightening values of nuts on bolts on your bike. That's some sound advice that many people in the bike industry has been giving over the years. Not many riders keep a tool like a torque wrench at home nor know how to use it. Meanwhile, you're most welcome to do a rebuttal of Dave's comments on my blog. I value the discussion. If you think something was stated wrong, come and talk about it.


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## apacherider (Mar 18, 2004)

Weird thing is, I use a Park Tool Torque Wrench and it only goes to 60 pounds. Huh.


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## Cozy.Beehive (Apr 12, 2009)

> Weird thing is, I use a Park Tool Torque Wrench and it only goes to 60 pounds. Huh.


Apache, agreed. Someone on my blog commented about getting calibration certificates for the wrench you used. Which is a valid statement because what if the tool one is using is completely inaccurate?

Now, based on your statement above, I have read that a torque wrench, calibrated by someone traceable to the National Bureau of Standards, is not accurate in the first 1/6th and last 1/6th of its range. So, a 60 ft.lb torque wrench is accurate only over the middle 2/3 of its range. *http://www.vansairforce.org/articles/tips/tip_torque_bolts.html *

If you have the original papers of the Park wrench, what do they say about periodical calibration, if any. You do know that this is a precision tool right? Everytime you drop this wrench, or toss it in a toolbox, there's a likelihood that the wrench is off its accuracy.


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## Jerk_Chicken (Oct 13, 2005)

Wow, this really is getting to be like those Loose Change guys because when they want you to believe what they are saying, they back it up using words from another similar site, which references yet another .org, and so on.


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## Cozy.Beehive (Apr 12, 2009)

http://www.parktool.com/repair/readhowto.asp?id=88

Here. See the section they talk about calibration.


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## Jerk_Chicken (Oct 13, 2005)

Noted is the edit after I posted.


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## wormvine (Oct 27, 2005)

Who do you work for Cozy? Your not Al Sharpton are you?


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## Cozy.Beehive (Apr 12, 2009)

wormvine said:


> Who do you work for Cozy? Your not Al Sharpton are you?


Al Sharpton is a college dropout. So no...


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## ettore (Nov 13, 2004)

There is essentially ZERO chance a torque wrench would indicate 60 in·lbs but is actually exerting 125+ in·lbs unless it is outright destroyed. Also, the OP isn't an idiot, he has easily been riding long enough to know what 60 in·lbs is roughly ... unless he was exerting 60 ft·lbs; that would be hilarious.

Hope the seatpost situation works out for you, I am not going to Mr. 20 posts (I think all in this thread, to be honest) website where it seems like he claims to have the story? I dunno.

BTW: I'd like to throw in that going to college has almost zero bearing on how intelligent you are; I went to MIT (I am not proud of this) and a substantial number of my fellow students were, at best, highschool intelligence.


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## wormvine (Oct 27, 2005)

Cozy.Beehive said:


> Al Sharpton is a college dropout. So no...


Who do you work for?


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## Cozy.Beehive (Apr 12, 2009)

wormvine said:


> Who do you work for?


http://www.exxonmobil.com/corporate/


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## Cozy.Beehive (Apr 12, 2009)

> There is essentially ZERO chance a torque wrench would indicate 60 in·lbs but is actually exerting 125+ in·lbs unless it is outright destroyed. Also, the OP isn't an idiot, he has easily been riding long enough to know what 60 in·lbs is roughly ... unless he was exerting 60 ft·lbs; that would be hilarious.


Roughly is not enough.


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## wormvine (Oct 27, 2005)

Cozy.Beehive said:


> Roughly is not enough.


Give us a fukin' break dude. If you think any of us are going to believe that a miscalibrated torque wrench caused the seatpost to fail, well you need to lay off the hooch Mr. Hazelwood! I am done with this stupidity. You are obviously a troll.


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## Cozy.Beehive (Apr 12, 2009)

> Give us a fukin' break dude. If you think any of us are going to believe that a miscalibrated torque wrench caused the seatpost to fail, well you need to lay off the hooch Mr. Hazelwood! I am done with this stupidity. You are obviously a troll.


50-60 in.lbs of torque can be generated by hand no doubt, even without a torque wrench. But what is "rough" according to you? 64 in-lbs may be roughly 60? That's plainly above the limit as per Thomson manual.

Giving those extra turns to nuts and bolts for that "extra" security is a false sense of security. It isn't conclusive that Op has an uncalibrated torque wrench, however I laid it out to him the possibility that a beam type wrench could be off zero unless checked. Why are you so hurt? Want a napkin?


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## Cozy.Beehive (Apr 12, 2009)

ettore said:


> BTW: I'd like to throw in that going to college has almost zero bearing on how intelligent you are; I went to MIT (I am not proud of this) and a substantial number of my fellow students were, at best, highschool intelligence.


That can be debated either way. Al Sharpton, however, is not very intelligent. We'd all be much better off without his 'preaching' and race-baiting. Reverend also thinks a pirate is a "voluntary coast guard'...  [http://www.thefoxnation.com/al-sharpton/2009/04/15/sharpton-calls-pirates-voluntary-coast-guard]


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## ettore (Nov 13, 2004)

Thomson is not manufacturing their seatposts with a 7% safety factor as is shown by the limited stories of breaking them ... plus this failure has nothing to do with bolt torque. Anyhow, I would say no torque wrench that is made of anything other than silly putty should go out of spec by over 10% no matter how you "store" it; my piece of garbage Sears torque wrench from 20+ years ago is dead nuts and I always forget to "release the spring" during storage. All these idiots that get their torque wrenches constantly calibrated, ask them how "off" they ever are.

Anyhow, a troll with a blog, I have a feeling this will not end soon.


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## Circlip (Mar 29, 2004)

I must admit that I'm not particularly concerned about the actual content regarding the failure of the post (despite being the owner of several Thomson posts and products) but I will say that Cozy.Beehive is an a$$ for culling a topic from a discussion forum and making it into a blog entry.

Furthermore, my opinion of Thomson the company has just been lowered a notch, that one of their staff would participate in what they must feel is a required public debunking of the reasons for the seatpost failure. I'm quite certain it would have been entirely acceptable to the vast majority of readers of this thread to simply dismiss the entire issue with thoughts similar to "Hmmm, that's interesting but seems pretty rare, and nice that the company stood behind their product in providing a replacement." Seems like a resolution that everyone could have lived with. One rare failure certainly wouldn't have been any reason for me to change my personal buying habits with respect to Thomson. But now with what's gone on...

Shame on both Cozy.Beehive and Thomson in this case, orchestrating and participating in a web flogging of this sort. The customer wasn't treated very well in the final analysis IMHO, and that _*will*_ have more of an effect on my buying decisions than the actual failure of the product.


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## Barkleyfan (Jul 26, 2008)

Cozy.Beehive said:


> Sorry, you lose. Your attitude is the traditional way of thinking and it doesn't help. All to often its easy to say 'things break, let's move on'. If this was someone in your family getting hurt, you would probably change your outlook. Your claims about Thomson's QC is some conjecture at best. I'm also not sure what caused you to "LMFAO". All this is a circus act to you.


Actually, I just have a realistic outlook. I've had parts fail. It sucks. You move on. It's not a "circus act" to me at all. It's just life. I try (and succeed, for the most part) to keep things in a balanced perspective. I abuse my bikes. Sometimes, I abuse them a little too much. Then I replace what I broke, and move on. If I can get it covered under warranty, cool. If not, I replace the part and move on anyways. The theme here is that I move the f*** on. Life's too short to dwell on petty s***. And I have to chalk a broken seatpost in the "petty s***" column.


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## Cozy.Beehive (Apr 12, 2009)

ettore said:


> Thomson is not manufacturing their seatposts with a 7% safety factor as is shown by the limited stories of breaking them ... plus this failure has nothing to do with bolt torque. Anyhow, I would say no torque wrench that is made of anything other than silly putty should go out of spec by over 10% no matter how you "store" it; my piece of garbage Sears torque wrench from 20+ years ago is dead nuts and I always forget to "release the spring" during storage. All these idiots that get their torque wrenches constantly calibrated, ask them how "off" they ever are.
> 
> Anyhow, a troll with a blog, I have a feeling this will not end soon.


*Following comments by Dave Parett from Thomson : *

_The fastener load is transferred, that should be easy to understand. You can take a fresh part, overtighten it and look for haze in the anodized surface. Interesting to see how load moves through the part. FEA will show you as well. The fasteners place the top of the post in tension against the force of the clamps. The radius from the head/ear area transfers some of the load from the top to the tube.

Here is the thing on the post. He may have used the wrench when he set it up originally, who knows, sounds like he is sure he did. No reason to dispute that. The point is that at some point in its life something happened to distort the allen sockets on the bolt heads and something caused divots to be formed in the cradle by the bottom clamp being forced into the cradle with a lot of force. Now that force comes from only 2 things, fastener load or an "event." I can't tell which, but it was one of the two. The post was in service for 4 years or so, it is conceivable that it was tightened more than once in it's life. If the anodic coating failed, you could get stress corrosion, but there is no evidence of that in this post. Let me repeat this part: Something exerted enough force on the post that the bottom clamp was driven into the cradle at the top of the post, and caused the clamp to dig into the material. Something happened to the post, either fastener load or an event. This is the one point that has not been answered and it is the answer that would tell us what happened.

I am not sure why this is hard to grasp. Pick a bike part, tighten down to 2.5 to 3 times rated torque and observe. Is that really not as simple as it sounds?

I can simulate the failure the guy had here. Just not sure what the confusion is. You take a setback post, tilt the saddle nose down, take the bolts to just before yield, and you will get the divots I see in this post. Keep in mind these are grade 12.8 steel bolts, with threads rolled after heat treat. They can take a high load. The heads of the bolts showed twisting/distortion that indicates they were near yield._


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## dascro (Apr 1, 2007)

Circlip said:


> I must admit that I'm not particularly concerned about the actual content regarding the failure of the post (despite being the owner of several Thomson posts and products) but I will say that Cozy.Beehive is an a$$ for culling a topic from a discussion forum and making it into a blog entry.
> 
> Furthermore, my opinion of Thomson the company has just been lowered a notch, that one of their staff would participate in what they must feel is a required public debunking of the reasons for the seatpost failure. I'm quite certain it would have been entirely acceptable to the vast majority of readers of this thread to simply dismiss the entire issue with thoughts similar to "Hmmm, that's interesting but seems pretty rare, and nice that the company stood behind their product in providing a replacement." Seems like a resolution that everyone could have lived with. One rare failure certainly wouldn't have been any reason for me to change my personal buying habits with respect to Thomson. But now with what's gone on...
> 
> Shame on both Cozy.Beehive and Thomson in this case, orchestrating and participating in a web flogging of this sort. The customer wasn't treated very well in the final analysis IMHO, and that _*will*_ have more of an effect on my buying decisions than the actual failure of the product.


I agree 100%. This is truly sickening and I truly hope he is not affiliated with Thomson, though I suspect otherwise.

What's even more sickening is he seems to think he knows so much more than anyone else here. He doesn't realize that he is making an ass of himself to those who really know what is going on with real experience in QA, FEA or manufacturing. WHAT A JOKE!


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## Circlip (Mar 29, 2004)

dascro said:


> I agree 100%. This is truly sickening and I truly hope he is not affiliated with Thomson, though I suspect otherwise.


Well, the engineer at Thomson is certainly an employee. While he may think that he's just giving matter-of-fact technical information, he showing he has crap for brains from a PR perspective, and is doing a good job of making what I thought was a respectable company look like a bunch of whiners instead. If any of the higher ups at Thomson have any common sense they'll put a gag order on their engineer before he digs an even deeper hole for them.


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## apacherider (Mar 18, 2004)

Well.....I guess this weekend what I'll do is see what the situation is with all my other Thomson seatposts. I have 4 more on 4 different bikes. All were put on with the same torque wrench I think. Friend of mine restores cars and I can borrow one of his super chi chi torque wrenches and test whatever torque is currently used on my other seatposts. Seems like that would be the right way to shadetree test it? Should be able to figure out within 5-6 pounds how tight the bolts are.

Sidenote: I was worried the minute Cozy Beehive picked up the scent of my post here. I saw that he linked this thread to his blog and shook my head a little. Just kind of said to myself "Oh, baby jesus, please dont let him get involved". But he did. 

The Thomson guy in this thread, who Cozy Beehive has been posting messages from seems to be a really nice guy. Like I said in an earlier post, he has been really nice and proactive, really top notch. I think Thomson should be lucky to have a guy like that. Not sure why any of you could read anything else into it than that. Some of you need to chill out and let him do his job.

Maybe Cozy Beehive needs to relax too. Like unplug his computer for awhile and do some riding or go for a long walk. Kind of wound up a little tight?


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## dascro (Apr 1, 2007)

Well now after looking through this again I'm even more throughly confused. Who is this cozy beehive and how is he involved? Why did he steal someone's post on here and make it the topic of his blog, why is he obsessed with it? Why does a Thomson company engineer or material scientist have so much time as to release public statements regarding this? As an engineer myself, I can say that doing something like that is a big no no if you value your career at a place, especially when you are making statements to one consumer about a failure that happened to another customer. Bizarre! 

What a fuster cluck this thread has become!


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## Cozy.Beehive (Apr 12, 2009)

apacherider said:


> Well.....I guess this weekend what I'll do is see what the situation is with all my other Thomson seatposts. I have 4 more on 4 different bikes. All were put on with the same torque wrench I think. Friend of mine restores cars and I can borrow one of his super chi chi torque wrenches and test whatever torque is currently used on my other seatposts. Seems like that would be the right way to shadetree test it? Should be able to figure out within 5-6 pounds how tight the bolts are.
> 
> Sidenote: I was worried the minute Cozy Beehive picked up the scent of my post here. I saw that he linked this thread to his blog and shook my head a little. Just kind of said to myself "Oh, baby jesus, please dont let him get involved". But he did.
> 
> ...


I'm worried about you man 

Keep safe. We're all nice guys.


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## Cozy.Beehive (Apr 12, 2009)

dascro said:


> Well now after looking through this again I'm even more throughly confused. Who is this cozy beehive and how is he involved? Why did he steal someone's post on here and make it the topic of his blog, why is he obsessed with it? Why does a Thomson company engineer or material scientist have so much time as to release public statements regarding this? As an engineer myself, I can say that doing something like that is a big no no if you value your career at a place, especially when you are making statements to one consumer about a failure that happened to another customer. Bizarre!
> 
> What a fuster cluck this thread has become!


Apparently, "stealing" is one thing, referencing it with proper citation is another. I did the latter if you didn't notice* (http://tiny.cc/APkhT)*. I'm pretty sure the forum, especially this thread, will have got some extra visits from non-members as a result. And then there's no telling how many from new visitors may have chosen to register . Look at the big picture.

I also think you misunderstood what I'm trying to do. I take an interest in failures and discussing them at length and I try my best to have the facts down on the table. If I haven't done so in the past, I apologize. The blog has great coverage, and a seatpost such as this is used by many people. If I can use a little bit of my time to spread known instances of failures and why they happened, I can get people to just double check their equipment which I believe will go a long way. Over the years, I have seen many people get hurt and injured pretty badly simply through wrong installation of bike parts or outrageous manufacturer failures that they had little role to play in. Sorry if this theme did not find favor with you.

Who's Cozy Beehive? Non-profit cycling blog. Zero ads. Just interesting information. Here's an introduction to the blog from the sponsor of this forum, Competitive Cyclist. [B]http://www.competitivecyclist.com/road-bikes/product-accessories/2008-belgium-knee-warmers-water-bottle-4972_49_TRUE.html[/B]


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## qbert2000 (Jul 30, 2008)

Cozy.Beehive said:


> Apparently, "stealing" is one thing, referencing it with proper citation is another. I did the latter if you didn't notice* (http://tiny.cc/APkhT)*. I'm pretty sure the forum, especially this thread, will have got some extra visits from non-members as a result. And then there's no telling how many from new visitors may have chosen to register . Look at the big picture.
> 
> I also think you misunderstood what I'm trying to do. I take an interest in failures and discussing them at length and I try my best to have the facts down on the table. If I haven't done so in the past, I apologize. The blog has great coverage, and a seatpost such as this is used by many people. If I can use a little bit of my time to spread known instances of failures and why they happened, I can get people to just double check their equipment which I believe will go a long way. Over the years, I have seen many people get hurt and injured pretty badly simply through wrong installation of bike parts or outrageous manufacturer failures that they had little role to play in. Sorry if this theme did not find favor with you.
> 
> Who's Cozy Beehive? Non-profit cycling blog. Zero ads. Just interesting information. Here's an introduction to the blog from the sponsor of this forum, Competitive Cyclist. [B]http://www.competitivecyclist.com/road-bikes/product-accessories/2008-belgium-knee-warmers-water-bottle-4972_49_TRUE.html[/B]


maybe you are neutral in this but if thomson says the bolts are to be torqued to 60in/pds what is the margin for error? surely the post won't fail at 65in/pds. as an "engineer" you know that things are tested to well beyond their recommended pressures or torque values. if the bolts are able to be tightened to 2.5 to 3 times their recommended values, maybe they should use a bolt that shears at the posts failure point. most things are tested to at least 1.5 times their recommended failure point. if thomson says the post should be torqed to 60 in/pds the posts should take 90 in/pds easily without failure.


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## Cozy.Beehive (Apr 12, 2009)

qbert2000 said:


> maybe you are neutral in this but if thomson says the bolts are to be torqued to 60in/pds what is the margin for error? surely the post won't fail at 65in/pds. as an "engineer" you know that things are tested to well beyond their recommended pressures or torque values. if the bolts are able to be tightened to 2.5 to 3 times their recommended values, maybe they should use a bolt that shears at the posts failure point. most things are tested to at least 1.5 times their recommended failure point. if thomson says the post should be torqed to 60 in/pds the posts should take 90 in/pds easily without failure.


Right, and I don't say that it's not a bad idea to do that, having the bolts shear before the entire post collapses. I'm offering suggestions to Thomson, about the bolts, radius of the head etc. So far they're absolutely convinced that theirs is a good design from FEA and testing and what not. But suffice to say, they're hearing this feedback and hopefully they'll review the design once more?


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## Jerk_Chicken (Oct 13, 2005)

Cozy.Beehive said:


> Who's Cozy Beehive? Non-profit cycling blog. Zero ads. Just interesting information. Here's an introduction to the blog from the sponsor of this forum, Competitive Cyclist. [B]http://www.competitivecyclist.com/road-bikes/product-accessories/2008-belgium-knee-warmers-water-bottle-4972_49_TRUE.html[/B]


Do you know for sure that Competitive Cyclist wants to be linked to you through your crusade?

Now it's getting silly because you're now trying to get legitimacy by associating yourself with whom you think might back you up.

Some years ago, Tony Ellsworth did the same thing, saying he's in some elite group of boutique builders. One of those builders registered to the site and told him outright to not reference him when speaking about himself. It was pretty clear what the actual association was.


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## Cozy.Beehive (Apr 12, 2009)

Jerk_Chicken said:


> Do you know for sure that Competitive Cyclist wants to be linked to you through your crusade?
> 
> Now it's getting silly because you're now trying to get legitimacy by associating yourself with whom you think might back you up.
> 
> Some years ago, Tony Ellsworth did the same thing, saying he's in some elite group of boutique builders. One of those builders registered to the site and told him outright to not reference him when speaking about himself. It was pretty clear what the actual association was.


Competitive Cyclist is not an engineering firm. Nevertheless, they take delight in reading a few blogs everyday, Belgium Knee Warmers, mine and some other one. I take pride in it and linked to it here since I thought it was relevant (CC is a sponsor here) They have not said otherwise. If they did, I don't think they'd bother towards giving precious real estate on their website to me. Either way I'm not too concerned.


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## Cozy.Beehive (Apr 12, 2009)

Circlip said:


> I must admit that I'm not particularly concerned about the actual content regarding the failure of the post (despite being the owner of several Thomson posts and products) but I will say that Cozy.Beehive is an a$$ for culling a topic from a discussion forum and making it into a blog entry.
> 
> Furthermore, my opinion of Thomson the company has just been lowered a notch, that one of their staff would participate in what they must feel is a required public debunking of the reasons for the seatpost failure. I'm quite certain it would have been entirely acceptable to the vast majority of readers of this thread to simply dismiss the entire issue with thoughts similar to "Hmmm, that's interesting but seems pretty rare, and nice that the company stood behind their product in providing a replacement." Seems like a resolution that everyone could have lived with. One rare failure certainly wouldn't have been any reason for me to change my personal buying habits with respect to Thomson. But now with what's gone on...
> 
> Shame on both Cozy.Beehive and Thomson in this case, orchestrating and participating in a web flogging of this sort. The customer wasn't treated very well in the final analysis IMHO, and that _*will*_ have more of an effect on my buying decisions than the actual failure of the product.


You say incidents like this are pretty rare, so the hell with the issue and the hell with discussion on the topic. Fine, if you don't like it...don't involve yourself. But you know something else that's rare? Airplane crashes. Your chances of being involved in an airplane crash is about 1 in 11 million, lower than the risk of it happening in a motor vehicle. Yet, IF there's an incident with an airplane (say a bolt failed in the landing gear upon touchdown), you don't say_ "Ahh, that was interesting...you know what, that's rare, and its good that Boeing usually builds good airplanes otherwise. It crashed too? 10 people seriously injured? Oh you know what, that's rare too...so I'll just sit here and discount the whole issue and pretend like it never even happened."_

Infact, if the head of Boeing said that publicly, you'd bet he'd be told that he needn't go to work the next day.

You might respond by saying I've got to put things into perspective and equating an airplane crash with a bicycle rider falling down and impaling himself is downright silly. But in either case, we're not talking about robots are we? These are people with lives, and families to support. You don't have to be a lawyer wearing an overcoat to understand that. You just have to value life, safety and the business of making good products that people can use reliably. If it fails, you have to question why it happened and try and prevent it from happening in future, whether that was a manufacturer fault or within the rider's scope. Road or offraod biking is a great and fun activity but let's face the brutal fact...injuries in cycling are nothing short of troublesome. I have been documenting this on my blog for the last 2-3 years actually. I'm not going to link it here because obviously some are apparently really put off by it so no big deal, I have zero problems with that.


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## Garlock (Jul 9, 2008)

apacherider said:


> *Had to ride 18 miles home standing.* That gets a little old after awhile. But not too bad. The weather was nice and I had the wind at my back.


Yeah right! I bet you caved. :nono: :skep:


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## mullet dew (Jun 4, 2008)

Cozy.Beehive said:


> You say incidents like this are pretty rare, so the hell with the issue and the hell with discussion on the topic. Fine, if you don't like it...don't involve yourself. But you know something else that's rare? Airplane crashes. Your chances of being involved in an airplane crash is about 1 in 11 million, lower than the risk of it happening in a motor vehicle. Yet, IF there's an incident with an airplane (say a bolt failed in the landing gear upon touchdown), you don't say_ "Ahh, that was interesting...you know what, that's rare, and its good that Boeing usually builds good airplanes otherwise. It crashed too? 10 people seriously injured? Oh you know what, that's rare too...so I'll just sit here and discount the whole issue and pretend like it never even happened."_
> 
> Infact, if the head of Boeing said that publicly, you'd bet he'd be told that he needn't go to work the next day.
> 
> You might respond by saying I've got to put things into perspective and equating an airplane crash with a bicycle rider falling down and impaling himself is downright silly. But in either case, we're not talking about robots are we? These are people with lives, and families to support. You don't have to be a lawyer wearing an overcoat to understand that. You just have to value life, safety and the business of making good products that people can use reliably. If it fails, you have to question why it happened and try and prevent it from happening in future, whether that was a manufacturer fault or within the rider's scope. Road or offraod biking is a great and fun activity but let's face the brutal fact...injuries in cycling are nothing short of troublesome. I have been documenting this on my blog for the last 2-3 years actually. I'm not going to link it here because obviously some are apparently really put off by it so no big deal, I have zero problems with that.


You are comparing a seatpost failure on a bike to a commercial airplane crash?
This down economy thing must be hurting bloggers worse than I thought.
You do this because you care about a handful of people having to wait a week or two to get a replacement post from thomson?
pathetic


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## Cozy.Beehive (Apr 12, 2009)

mullet dew said:


> You are comparing a seatpost failure on a bike to a commercial airplane crash?
> This down economy thing must be hurting bloggers worse than I thought.
> You do this because you care about a handful of people having to wait a week or two to get a replacement post from thomson?
> pathetic


What gives you the monopoly to believe that the next group of people having such an incident won't have a serious injury? Will a replacement post make up for the medical expenses and lost time from work?


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## xmangox (Feb 20, 2009)

Thomson is the best. Parts fail if installed incorrectly...and sometimes given the right circumstances they will fail if installed correctly. 

I will still buy their products.


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## dascro (Apr 1, 2007)

Cozy.Beehive said:


> What gives you the monopoly to believe that the next group of people having such an incident won't have a serious injury? Will a replacement post make up for the medical expenses and lost time from work?


Alright, I've been watching this debacle for a while now and feel I need add my 2 cents. This failure analysis you are doing is a hobby. A slightly odd one IMO but one none the less. I think you are making a bit of a fool out of yourself making it out to be this noble crusade preventing injuries. That is, unless you are an engineer turned attorney looking for some work...

I agree we need to prevent injuries as often as possible. But we are in a dangerous sport, riding a bike made up of the lightest components imaginable. Injury is something everyone who's ridden has dealt with and accepted. Does injury due to part failure suck? Yes very much so but it happens. Reading this is starting to make me think of our lawsuit happy American society and how these a$$hat attorneys act like they are doing good for society. A common failure is a problem, one failure out of many thousands, or maybe millions is not. No, not ideal, but not a problem that requires this crusade you are on.

The comparison to the aircraft industry keeps popping up. How familiar are you with the industry? No doubt the standards are higher, but this is due to countless additional certifications and similar that are in place.

What aircraft quality? Then pay aircraft prices.


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## mullet dew (Jun 4, 2008)

Cozy.Beehive said:


> What gives you the monopoly to believe that the next group of people having such an incident won't have a serious injury? Will a replacement post make up for the medical expenses and lost time from work?


Mountain biking is a dangerous sport, no component/frame manufacture out there pays your medical bills because you chose to participate in a dangerous sport where components can fail, nor should they.


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## SVO (May 25, 2005)

Terms of use of the site define rights to content. Cannot steal from another user. 

This is SO BORRRRRRING! One failure is almost meaningless. Several with identical characteristics needed before it would likely be a mfg defect. "I always use a torque wrench calibrated a microsecond before by mass spectrometer..." He's got a little Marissa Tomei thing going... And I'm sure the bike was never out his sight 24/7 so that no friend or mechanic ever had an opportunity to pick up a hex and crank on it... Sh%t happens. Not injured. Move on.


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## 4JawChuck (Dec 1, 2008)

I was playing hockey the other night (playoffs get me all horny ya know) and as I was skating down one on one with the goalie I was going to tee it up and suddenly *SNAP* I broke my stick?!

WTH happened? I hardly hit the puck with the stick and it still broke? I got a sliver from the broken end when my hand pulled back on the stick. You ever get a carbon fiber sliver? Dang they hurt!

Here's a picture of the break, perhaps you guys can help me determine why it broke.










.
.
.
.Sound silly?


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## D.F.L. (Jan 3, 2004)

http://www.mtbr.com/guidelinescrx.aspx#manuguidelines


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## Waspinator (Dec 27, 2004)

apacherider said:


> I'm OK, which is the main thing. Seriously, if I had not been riding on smooth concrete, this would have been a compete disaster. Added help was that I have a small Cannondale seatbag for a spare tube under my seat with small velcro loop that goes around the post in addition to the seat rails. That's the only thing that saved me from an aluminun colonoscopy. I have 5 Thomson seatposts and never had an issue with any of them till today. Across those posts I have over 100,000 care free miles. Owned this particular post 10 months and about 2000 miles. It's a Thomson Setback 31.6 410mm I have been using in Cannondale Caffeine framesets. The post has never been dropped, wrecked, knock over or even put in a repair stand.
> 
> Frankly I did not think this was possible because I read that the bolts are supposed to break before the seatpost. I have not even heard of a Thomson failure before.


You sound appalled that a _Thomson _seatpost would break, as if Thomson is be-all-end-all of seatposts. I ride Syncros posts exclusively and have never had a failure (and I'm a 225lb guy who sits on the saddle most of the time). But seriously, how often do you hear of aluminum seatpost failures to begin with?

Anyways, I don't see how a seatpost bolt will fail first unless you put all your weight on the nose of the saddle all the time.

And to be honest, I personally think that the Thomson layback design with the bent shaft is a bad one. I'm amazed that more of their seatposts don't fail at the bend, which serves as a perfect kink for an aluminum tube to bend.


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## apacherider (Mar 18, 2004)

SVO said:


> He's got a little Marissa Tomei thing going... And I'm sure the bike was never out his sight 24/7 so that no friend or mechanic ever had an opportunity to pick up a hex and crank on it... Sh%t happens. Not injured. Move on.


I'm the only one that rode it and wrenched on it.

Like I said, only reason I was not injured was because of the seatbag under the saddle. This is how the seat is setup, I just got the replacement seatpost from Thomson a couple days ago. Thought I would get a seatpost replacement sooner...ended up having to buy a new one while waiting for the replacement, an Interloc Racing Design 425mm:










You can see from how the seatbag is setup that when the Thomson failed the velcro piece around the post kept it together.

The IRD seatpost is really nice. Probably will leave it on the bike.

I agree that "Sh%t happens" it was never my intention to whack at a hornet's nest with my thread, seems that a couple other posters have taken that up though!

My thread is a cautionary tale, that nothing is unbreakable, perfect or worth the praise that some people heap on it.


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## apacherider (Mar 18, 2004)

Waspinator said:


> You sound appalled that a _Thomson _seatpost would break


It's a rare bear.

From the looks of things, your posts are all troll bait flamefests anyway.


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## Mike T. (Dec 30, 2003)

apacherider said:


> Had to ride 18 miles home standing.


18 miles!! Back in the day, Cindy Whitehead had you beat by 32 miles. She was a tough 'un -

http://sonic.net/~ckelly/Seekay/whitehead.htm


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## nuj (Jul 27, 2008)

hello, i've heard a lot of nice things about thompson seatpost. aside from they're being tough they are very expensive too. thats the reason i never buy them specially here in my country where you can't return the item once used. its a good thing you'll be able to use that wonderful word you all out there been using if something like this ever happen WARRANTY


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