Chain Failure

On 07/02/12 10:00, Andreas Oehler wrote:
Tue, 07 Feb 2012 08:34:54 +1100, James:

On 07/02/12 07:45, Andreas Oehler wrote:
Mon, 06 Feb 2012 09:54:46 -0500, (PeteCresswell):

Anybody want to speculate on the cause of this one?

http://tinyurl.com/6u6qm6c

I had similar failures in the last Winters. Two middle class Shimano
chains and one from Wippermann:
http://velo.dyndns.eu/bilder/connex-riss.jpg

In all cases the chains had been used on heavily salted roads for weaks
without cleaning. Modern de-icing salts are a nasty high corrosive mixture
- which might induce cracks. The other bikes the family uses with similar
chains on similar roads had no problems with the chain - but they all use
chain cases:
http://velo.dyndns.eu/bilder/chaingl...penherbst1.jpg

Could rust between the pin and side plate swell and cause the side plate
to crack?

Would a stainless steel chain survive better? Or is the grade of
stainless not sufficient to resist that kind of corrosion?

The Wippermann in the picture has "stainless" sideplates...

It does appear that the pins are more corroded than the side plates.

Expanding pin splits side plate?

--
JS.

"James" wrote in message
...
On 07/02/12 10:00, Andreas Oehler wrote:
Tue, 07 Feb 2012 08:34:54 +1100, James:

On 07/02/12 07:45, Andreas Oehler wrote:
Mon, 06 Feb 2012 09:54:46 -0500, (PeteCresswell):

Anybody want to speculate on the cause of this one?

http://tinyurl.com/6u6qm6c

I had similar failures in the last Winters. Two middle class
Shimano
chains and one from Wippermann:
http://velo.dyndns.eu/bilder/connex-riss.jpg

In all cases the chains had been used on heavily salted roads for
weaks
without cleaning. Modern de-icing salts are a nasty high corrosive
mixture
- which might induce cracks. The other bikes the family uses with
similar
chains on similar roads had no problems with the chain - but they
all use
chain cases:
http://velo.dyndns.eu/bilder/chaingl...penherbst1.jpg

Could rust between the pin and side plate swell and cause the side
plate
to crack?

Would a stainless steel chain survive better? Or is the grade of
stainless not sufficient to resist that kind of corrosion?

The Wippermann in the picture has "stainless" sideplates...

It does appear that the pins are more corroded than the side plates.

Expanding pin splits side plate?

--
JS.

Stainless is weaker than cold steel, that probably is the reason the
stainless side plates split.
Unless it's a stainless finish.

Cheers

On 2/6/2012 12:34 PM, James wrote:


It looks as though the lower half has been broken for a long time,
judging by the black muck over the broken section, where as the top half
is freshly broken, with no black muck on it.

It looks to be a faulty chain.

Yup, I think so. I had a similar looking failure a few year back:
http://home.comcast.net/~mandmlj/BrokenChain/index.html

At the time, some blamed the soaks (maybe only once?) in Simple Green
cleaner. Others said SRAM had a run of faulty chains.
I've avoided long soaks in Simple Green since then, and after a short
time, went back to SRAM chains. No problems since.

I tend to think the chain was bad.

Mark J.

On Mon, 06 Feb 2012 09:54:46 -0500, "(PeteCresswell)"
wrote:

Anybody want to speculate on the cause of this one?

http://tinyurl.com/6u6qm6c

I discovered it when the chain dropped under light pedaling.
Thought "geeze, that thing wasn't loose enough to do that...
let's take a look..." and there it was. Not quite as nasty as
the pic bc at that point I figured maybe I could nurse it home
with really light pedaling... but no-go and the pic shows it
after it dropped the second time.

Yeah, the chain overall is pretty nasty - but that's bc I ran out
of ProLink a few months ago and got the bright idea of lubing it
with motor oil. Live and learn....

This chain not unduly worn per the Rohloff chain gauge I put on
it and it has never seen a chain tool... ever.

It was on my SS, so there was no possibility of it's having been
weakened by a der crash and the rear cog is far enough away from
the stay that there's no possibility of it having been wedged.

I've got a theory, but don't want to pollute the answer space
yet.

Dear Pete,

Consider stress corrosion cracking.

Here's a sample of posts on the matter:
http://groups.google.com/group/rec.b...e84d302b3673b0

Cheers,

Carl Fogel

Per Mark J.:

Yup, I think so. I had a similar looking failure a few year back:
http://home.comcast.net/~mandmlj/BrokenChain/index.html

The funny part is that, for about the last 30 years, I had been
carrying a chain tool and a few inches of spare links in my
toolkit. Never used, of course.

But a few years ago, I thought "What? Are you some kind of
obsessive carrying this stuff?" .... and stopped carrying it.
--
Pete Cresswell

Per Lou Holtman:
Operator error! ;-)

Actually, that was the first thing I thought of.

Didn't want to pollute the answer space with my baseless theory,
but now that we've got some other theories....

The same day, before that ride, I pulled the rear wheel to
re-shim the brake caliper.

Put it all back together, locked in the wheel, and then realized
I had not put the chain on the chain wheel.

The state of wear on the chain and the setting of the rear wheel
was such that I figured I could just roll the chain on to the
chain wheel, give it a crank, and be done.

That's how it worked, but I had to rotate the cranks a little
harder than I expected. My bet was that I introduced some sort
of side force on the links as they were climbing on to the chain
wheel.
--
Pete Cresswell

On Feb 6, 11:55*pm, "Mark J." wrote:
On 2/6/2012 12:34 PM, James wrote:



It looks as though the lower half has been broken for a long time,
judging by the black muck over the broken section, where as the top half
is freshly broken, with no black muck on it.

It looks to be a faulty chain.

Yup, I think so. *I had a similar looking failure a few year back:http://home.comcast.net/~mandmlj/BrokenChain/index.html

At the time, some blamed the soaks (maybe only once?) in Simple Green
cleaner. *Others said SRAM had a run of faulty chains.
I've avoided long soaks in Simple Green since then, and after a short
time, went back to SRAM chains. *No problems since.

I tend to think the chain was bad.

The gf had a similar failure last week as well on her barn fresh ~97
Multitrack. By the look of the other wear on it, the bike had less
than five hundred miles on it when I refreshed it last October. The
chain was dry-sticky like it still had factory cosmoline on it. Her
shifting was sketchy and I thought it might be old lube in the
gripshift or a bent hanger. It shifted so badly one morning on her
commute that she bruised her tailbone on the saddle horn. Then a
couple weeks later, we took a slow roll through the local greenway and
I saw the chain jump when it rolled onto the tension pulley and
jockey. Had her stop so I could fix the "obviously" sticky link. Found
a similarly cracked side plate. Whew. We got her to the shop and threw
a new SRAM PC 850 on. But if she'd honked out of the saddle once more
on her commute--it probably would have been oral reconstruction time.
Yikes.

It obviously wasn't a mileage issue. It was visually new and measured
a perfect 12" when I restored the thing. Wasn't a lube issue. Just
some Pro-gold on top of the factory cosmo. It *was* a Shimano chain--
somewhat of a liability. So I'm guessing manufacturing defect--or
perhaps an impact from being moved around in a garage but never ridden
for fifteen years--Frank's theory.

(PeteCresswell) wrote:
Per Lou Holtman:
Operator error! ;-)

Actually, that was the first thing I thought of.

Didn't want to pollute the answer space with my baseless theory,
but now that we've got some other theories....

The same day, before that ride, I pulled the rear wheel to
re-shim the brake caliper.

Put it all back together, locked in the wheel, and then realized
I had not put the chain on the chain wheel.

The state of wear on the chain and the setting of the rear wheel
was such that I figured I could just roll the chain on to the
chain wheel, give it a crank, and be done.

That's how it worked, but I had to rotate the cranks a little
harder than I expected. My bet was that I introduced some sort
of side force on the links as they were climbing on to the chain
wheel.

Like shoulder joints, you can do that just once and it's
wrecked. Unlike shoulder joints, chain is easily exchanged
for new.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

"(PeteCresswell)" wrote in message
...
Per Mark J.:

Yup, I think so. I had a similar looking failure a few year back:
http://home.comcast.net/~mandmlj/BrokenChain/index.html

The funny part is that, for about the last 30 years, I had been
carrying a chain tool and a few inches of spare links in my
toolkit. Never used, of course.

But a few years ago, I thought "What? Are you some kind of
obsessive carrying this stuff?" .... and stopped carrying it.

Over the years I've snapped plenty of motorcycle chains - 2 spare
split-links joined together with a plain inner on my keyring, but not the
one that hangs from the ignition barrel.

In article ,
lid says...


Anybody want to speculate on the cause of this one?

http://tinyurl.com/6u6qm6c

I discovered it when the chain dropped under light pedaling.
Thought "geeze, that thing wasn't loose enough to do that...
let's take a look..." and there it was. Not quite as nasty as
the pic bc at that point I figured maybe I could nurse it home
with really light pedaling... but no-go and the pic shows it
after it dropped the second time.

Yeah, the chain overall is pretty nasty - but that's bc I ran out
of ProLink a few months ago and got the bright idea of lubing it
with motor oil. Live and learn....

This chain not unduly worn per the Rohloff chain gauge I put on
it and it has never seen a chain tool... ever.

It was on my SS, so there was no possibility of it's having been
weakened by a der crash and the rear cog is far enough away from
the stay that there's no possibility of it having been wedged.

I've got a theory, but don't want to pollute the answer space
yet.
--
Pete Cresswell

Brand of chain?