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Self destructing Campy SR derailleur

Posted: Sun Jan 21, 2018 2:00 pm
by arthurf
Hi all,

Out riding this morning when my SR derailleur seemingly self destructed! It’s only 10 months old and has never taken any side impact but it seems to have failed just below the frame bolt. The hanger seems ok and I wasn’t cross chaining when it went. Any idea what could have caused this? Warranty claim?

Thanks

Arthurf

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Re: Self destructing Campy SR derailleur

Posted: Sun Jan 21, 2018 2:34 pm
by kavitator
R.I.P


little stone gets in chain and jam ?

Re: Self destructing Campy SR derailleur

Posted: Sun Jan 21, 2018 3:00 pm
by Calnago
From the looks of things.... the chain is jammed between the spokes and the largest sprocket and the position of the rear derailleur housing shows pretty clearly that the derailleur took a little journey up and around, versus just breaking off and settling where it is.... so, no warranty as it is due to the derailleur going into the spokes. But if a shop set things up not too long ago, and you really have no reason to believe the derailleur hanger had gotten bent in a fall or something, then I’d be taking it back to the shop since the lower limit screw was not adjusted properly. Unfortunately, your rear derailleur hanger did not break away during the process. Bad luck.

Re: Self destructing Campy SR derailleur

Posted: Sun Jan 21, 2018 3:58 pm
by Butcher
+1

Re: Self destructing Campy SR derailleur

Posted: Sun Jan 21, 2018 5:40 pm
by wilwil
If the mech went into those spokes there would be damage or at least marks on the spokes.

Re: Self destructing Campy SR derailleur

Posted: Sun Jan 21, 2018 6:20 pm
by bilwit
something made the chain get caught or stuck (dropped out of a jockey wheel and wasn't pushed back in maybe?) which pulled the arm as far as possible while pedaling until it was ripped clean off -- I had this happen to me in the past (luckily it was only a 105 RD)

Re: Self destructing Campy SR derailleur

Posted: Sun Jan 21, 2018 7:04 pm
by Bridgeman
Years ago, I had this happen. I think it started when I felt a wheel from behind while on a large aggressive group ride. Maybe 15 minutes later my rear wheel locked up on a short downhill section. I might still have that mangled rear derailleur.

Turns out, the rear derailleur opened up into the rear wheel. I'm certain that rear-end I received was contact to the rear derailleur, thereby weakening the carbon fiber parallelogram.

Re: Self destructing Campy SR derailleur

Posted: Sun Jan 21, 2018 7:11 pm
by kode54
this happened to me once on the older carbon SR RD. what happened to me was during the fall, when leaves are on the road and such. a little branch flicked up and got caught in my jockey wheels (i think), tore the hanger off and snapped the RD to bits. caused me to go down on a turn and caused damage to the rear wheel/spokes and chain stay. didn't break the chain stay (Storck bike at the time)...but gouged the carbon a bit.

Re: Self destructing Campy SR derailleur

Posted: Sun Jan 21, 2018 7:14 pm
by arthurf
Thanks guys, looks like I’ll just have to suck up the cost for a new derailleur 👎

Re: Self destructing Campy SR derailleur

Posted: Sun Jan 21, 2018 7:55 pm
by bm0p700f
If the chain is too short then that could be another cause of failure.

Re: Self destructing Campy SR derailleur

Posted: Sun Jan 21, 2018 9:00 pm
by Bridgeman
Sometimes damage can take place without you being present. Coffee shops, where large groups frequent is an example.

I've experience damage from this type environment from a smug a**hole. I was lucky in that I was made aware of it as it was happening. Sometimes that doesn't happen.

Upon impact, components can be partially damaged, only to later fail when they have been cycled through their high stress excursions.

Sometimes it's kind of like catching a cold. You can never be absolutely sure where you picked it up.

Re: Self destructing Campy SR derailleur

Posted: Tue Jan 23, 2018 5:57 am
by Allen254
make sure hanger screws are tight and have lock tight

Hoping not a trend

Posted: Tue Jan 23, 2018 7:30 am
by beeatnik
https://forums.thepaceline.net/showpost ... stcount=23

https://forums.thepaceline.net/showpost ... stcount=40

Back in the Spring I built a Soma Fogcutter for an all-purpose bike. Campagnolo Chorus cranks with Potenza shifters and derailleurs, 11-32 cassette. I put several hundred road/gravel/single track miles on it without a problem or accident.
Yet on my first REAL gravel ride (in the mountains,think Southern Cross combined with Six Gap) the rear derailleur begins shifting poorly. I reach the lowest point on the route and the plastic knuckle on the Potenza rear derailleur separates/breaks, requiring me to single speed it (mostly uphill now) 40ish miles back to the car.
I noticed a lot of chain slap (on the descents) before the derailleur broke, and I expect this caused the knuckle to separate. I encountered no sticks and had no crashes on this bike up to this point.
I'm pleased with all of the Potenza components EXCEPT the rear derailleur. I've left that plastic part off of my bike from here on.

Re: Self destructing Campy SR derailleur

Posted: Tue Jan 23, 2018 11:04 am
by mattr