broken chain mystery

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lee
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Re: broken chain mystery

Post by lee » 13 Apr 2015, 10:52

Cabernet wrote:I love ❤ my shaft.
High on the list of things the next bike must have.
Fuck these chains.

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Stumoores
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Re: broken chain mystery

Post by Stumoores » 13 Apr 2015, 10:59

It's only a bike if it's got a chain. It's half a car if it's got a shaft


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Revving the bollox off it since 1982

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Paul m0kdm
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Re: broken chain mystery

Post by Paul m0kdm » 13 Apr 2015, 11:41

If it's an O ring or X ring type chain aggressive cleaning can damage the seals and flush out the factory injected lubricant. This can lead to localised heating of the links due to friction. Hot metal expands, and basically something's got to give. Just a wipe over with a paraffin soaked rag to clean it, then a lube, job done.
No acid, wire brushes etc. Even the 3 sided chain cleaning brushes can damage the seals if you're not careful.

Yep, I've done it. :-)

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ned
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Re: broken chain mystery

Post by ned » 13 Apr 2015, 14:09

Dooffle wrote:Doubtful that corrosion would have caused the failure, unless it was very badly pitted. It's also possible that acid cleaning has compounded a slight flaw in the material.

Was it the soft link (joining link)? If so it is likely that a stress fracture was caused buy the link being peened.
The pin looks in good condition so unlikely to be caused by a tight link. The cause could also be from a single high force incident ie sudden impact.
Could have been a small inclusion in the material.
Without a good look at the fracture face to asses the type of break it's hard to say.
PS this is the sort of thing I do for a day job.




Last year I had an expensive chain (£120) break, clean through a link, stress fracture. Nowhere near the soft link.
Bought a chain for £60 due to emergency, I have only just adjusted it after 2.5k miles, including 2 trackdays.
The fracture you can see that has the rusted surface I's deffo an old one and the soft link is in good order. It is looking mire like my falling of the bike stressed the offending link

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Stumoores
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Re: broken chain mystery

Post by Stumoores » 13 Apr 2015, 18:05

Hydrogen embrittlement


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Dooffle
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Re: broken chain mystery

Post by Dooffle » 13 Apr 2015, 19:41

pch1 wrote:
Dooffle wrote:
face to asses...
PS this is the sort of thing I do for a day job.

Face to arses? Don't think I'd like your job mate, sounds a bit shit if you ask me lol

Viva BMW shaft drive \o/
:shock: ;)

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ned
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Re: broken chain mystery

Post by ned » 13 Apr 2015, 21:37

What the fuck is hydrogen embrittlement? ?

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Cabernet
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Re: broken chain mystery

Post by Cabernet » 13 Apr 2015, 22:46

ned wrote:What the fuck is hydrogen embrittlement? ?
Ice cold hydrogen, the waste gas being exhausted at high pressure from the flux capacitor causing cryogenic freezing.
A Kentish man living in Manchester.

"As soon as he (Tozzi) started with the personal remarks I assumed he was struggling with the rest of his case", Ross Brawn 2009,


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