Shocking picture reveals cause of chain breaking

[Ivar Hesselager]

I drove out after work today and picked up the broken Shimano Ultegra CN
6600 chain from the garbage can I dropped it in on sunday after my fairly
lucky fall.

The result of the examiniation was very interesting:. The breaking was
definately not caused by an inadequately placed connecting pin, as
suggested by several, in the thread below, as the chain was assembled
with at connecting link from KMC.

It was evidently caused by a crack in one or two sideplates.
Besides the two broken sideplates, I found four other plates with cracks
in them. Two on either side of the chain, on different links, not close
to each other.

On the picture you can clearly see the cracks in two links, that I placed
just underneath the broken link.

http://www.23hq.com/ihl/photo/2830930/original

What I still don't know is why a chain is cracked. Could it possibly
have anything to do with the chain cleaner I use: Rex Cleaner Plus?
Motorex is a big and well known company, so it would surpise me greatly,
if they produce a chain cleaner that makes the chains fall apart.

Should Shimano be warned about this potentially dangerous fault in their
chain? Would they be interested?

Ivar of Denmark

 

[Ivar Hesselager]

Den 24.01.2008 kl. 02:24 skrev Ivar Hesselager <[email protected]>:

Sorry the link dosn't work.
>
> http://www.23hq.com/ihl/photo/2830930/original
>

it's a good picture though, so I will try to find another way to get it
out.

Ivar

 

[Bill Sornson]

Ivar Hesselager wrote:
> Den 24.01.2008 kl. 02:24 skrev Ivar Hesselager
> <[email protected]>:
> Sorry the link dosn't work.
>>
>> http://www.23hq.com/ihl/photo/2830930/original

Thought you were shilling for "The Number 23".

> it's a good picture though, so I will try to find another way to get
> it out.

Since no one else will get it, I'll say it: nice irony having a broken link
about broken links!

Bill "deep" S.

 

[jim beam]

Ivar Hesselager wrote:
> Den 24.01.2008 kl. 02:24 skrev Ivar Hesselager <[email protected]>:
>
> Sorry the link dosn't work.
>>
>> http://www.23hq.com/ihl/photo/2830930/original
>>
>
> it's a good picture though, so I will try to find another way to get it
> out.
>
> Ivar


try this:
http://www.23hq.com/ihl/photo/2830930

judging by the fact that there are other cracked plates there in
addition to the link that broke, i'd say you've been using a stress
corrosion agent for chain cleaning.

"cleaning" is a pointless exercise - it washes grit into the chain's
bearings and accelerates wear. simply lube, wipe, ride, repeat.
replace when worn.

 

[buzz66]

How many Miles did the chain do?

 

[Ben C]

On 2008-01-24, jim beam <[email protected]> wrote:
> Ivar Hesselager wrote:
>> Den 24.01.2008 kl. 02:24 skrev Ivar Hesselager <[email protected]>:
>>
[...]
> try this:
> http://www.23hq.com/ihl/photo/2830930
>
> judging by the fact that there are other cracked plates there in
> addition to the link that broke, i'd say you've been using a stress
> corrosion agent for chain cleaning.

Does that explain why the cracks in all three cracked links in that
picture are all in roughly the same place?

Perhaps there is higher stress there caused by the pins pushing the
sideplates out radially, hence more corrosion there?

 

[jim beam]

Ben C wrote:
> On 2008-01-24, jim beam <[email protected]> wrote:
>> Ivar Hesselager wrote:
>>> Den 24.01.2008 kl. 02:24 skrev Ivar Hesselager <[email protected]>:
>>>
> [...]
>> try this:
>> http://www.23hq.com/ihl/photo/2830930
>>
>> judging by the fact that there are other cracked plates there in
>> addition to the link that broke, i'd say you've been using a stress
>> corrosion agent for chain cleaning.
>
> Does that explain why the cracks in all three cracked links in that
> picture are all in roughly the same place?
>
> Perhaps there is higher stress there caused by the pins pushing the
> sideplates out radially, hence more corrosion there?


yup, absolutely. ["_stress_ corrosion", not "corrosion" - different
mechanisms]

 

[Werehatrack]

On Thu, 24 Jan 2008 02:24:58 +0100, "Ivar Hesselager"
<[email protected]> may have said:

>I drove out after work today and picked up the broken Shimano Ultegra CN
>6600 chain from the garbage can I dropped it in on sunday after my fairly
>lucky fall.
>
>The result of the examiniation was very interesting:. The breaking was
>definately not caused by an inadequately placed connecting pin, as
>suggested by several, in the thread below, as the chain was assembled
>with at connecting link from KMC.
>
>It was evidently caused by a crack in one or two sideplates.
>Besides the two broken sideplates, I found four other plates with cracks
>in them. Two on either side of the chain, on different links, not close
>to each other.
[snip]
> What I still don't know is why a chain is cracked. Could it possibly
>have anything to do with the chain cleaner I use: Rex Cleaner Plus?
>Motorex is a big and well known company, so it would surpise me greatly,
>if they produce a chain cleaner that makes the chains fall apart.

In trying a number of different cleaning and corrosion removal
preparations on old, worn chains, I discovered that both highly acidic
and highly alkaline solutions can lead to cracking of the side plates,
usually from the pin to the tip of the plate within 1mm of the plate's
centerline, apparently due to etching of the metal or selective
erosion of alloy components. This has even happened with old 7sp and
8sp chains when the solution was strong enough or was left on the
chain long enough.

>Should Shimano be warned about this potentially dangerous fault in their
>chain?

I suspect that they know. Note that they do not recommend cleaning
with anything but a wipe-down using a rag or such.

> Would they be interested?

Shimano has shown a remarkable lack of concern for other revelations,
and it has been commented that they seem to want to avoid embracing
any knowledge that does not originate from within their own structure.

My suspicion is that their response, if any, would be along the lines
of "Shimano does not recommend the use of any chain cleaning procedure
or chemical that is not explicitly mentioned in out tech documents."

If, OTOH, there's a genuine fault in the product, it might be worth
alerting them to the fact that you have a sample that has failed. In
such a case, they might either replace it or want the old one for
examination. ("For examination" being a way to get faulty products
back off the street before they can become a larger embarassment.)

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

 

[[email protected]]

Where's the hat rack writes:

> In trying a number of different cleaning and corrosion removal
> preparations on old, worn chains, I discovered that both highly
> acidic and highly alkaline solutions can lead to cracking of the
> side plates, usually from the pin to the tip of the plate within 1mm
> of the plate's centerline, apparently due to etching of the metal or
> selective erosion of alloy components. This has even happened with
> old 7sp and 8sp chains when the solution was strong enough or was
> left on the chain long enough.

>> Should Shimano be warned about this potentially dangerous fault in
>> their chain?

> I suspect that they know. Note that they do not recommend cleaning
> with anything but a wipe-down using a rag or such.

That's interesting. What does wiping a chain with a rag do for its
longevity? That can only help get external grit into the chain
interior where it can act as an abrasive. Add a little lubricant and
the grinding past is complete, and elongated chain pitch from internal
wear is the main culprit in damaging sprockets.

>> Would they be interested?

> Shimano has shown a remarkable lack of concern for other
> revelations, and it has been commented that they seem to want to
> avoid embracing any knowledge that does not originate from within
> their own structure.

I think they isolate themselves with their "no outside technical
information" policy. Their employees are forbidden to discuss
technical matters at trade shows like InterBike.

> My suspicion is that their response, if any, would be along the
> lines of "Shimano does not recommend the use of any chain cleaning
> procedure or chemical that is not explicitly mentioned in out tech
> documents."

It sells more chains.

> If, OTOH, there's a genuine fault in the product, it might be worth
> alerting them to the fact that you have a sample that has failed. In
> such a case, they might either replace it or want the old one for
> examination. ("For examination" being a way to get faulty products
> back off the street before they can become a larger embarrassment.)

They can't hear you, or don't want to.

Jobst Brandt

 

[jim beam]

[email protected] wrote:
<snip underinformed paranoia>
> They can't hear you, or don't want to.

that's a spectacularly ironic statement coming from you jobst!

 

[Michael Baldwin]

Ivar asks

>What I still don't know is why a chain is
>cracked.

Hello Ivar

I sincerely appreciate the effort you've put into this post. (pics &
details)

I'm not discounting any other opinions. However regarding your
question, I'm leaning toward residual stress incurred during assembly.

Consider yourself lucky that you were not injured as a result of this
failure. Inspect your chain/s more frequently. And maybe heed the
advice of others and change your clean/lube routine.

Again, another prime example of (here it comes Jobst) when "variables
collide".

Best Regards - Mike Baldwin

 

[jim beam]

Michael Baldwin wrote:
> Ivar asks
>
>> What I still don't know is why a chain is
>> cracked.
>
> Hello Ivar
>
> I sincerely appreciate the effort you've put into this post. (pics &
> details)
>
> I'm not discounting any other opinions. However regarding your
> question, I'm leaning toward residual stress incurred during assembly.

there's "assembly stress" if you will - the rivet is an interference fit
with the plate and thus there's a hoop stress, but that's not residual
stress. from the rolling operation that makes the plates, you would
expect any residual stress cracking to be manifest longitudinally, and
even then, there needs to be an agent that causes the cracking if the
stress is present. therefore, the likely cause is stress corrosion.
residual stress need not be present if there's applied stress.


>
> Consider yourself lucky that you were not injured as a result of this
> failure. Inspect your chain/s more frequently. And maybe heed the
> advice of others and change your clean/lube routine.
>
> Again, another prime example of (here it comes Jobst) when "variables
> collide".
>
> Best Regards - Mike Baldwin
>

 

[jim beam]

jim beam wrote:
> [email protected] wrote:
> <snip underinformed paranoia>
>> They can't hear you, or don't want to.
>
> that's a spectacularly ironic statement coming from you jobst!

http://www.tfot.info/news/1094/some-people-never-learn.html