Record 12 / Cervelo Failure

[yinzerniner]

Unfortunately this is a somewhat common occurrence with the carbon Campy RD's.

Don't think it's fully widespread but has happened enough that you really have to be cognizant of checking the rear derailleur structural integrity before every ride.

Basically, the material around the derailleur hanger has a tendency to crack and fail without warning, either through a decent amount of use or when the chain and jokey wheels get jammed with debris. When that happens it just gets sucked right into the rear wheel and the damage is catastrophic.

https://weightweenies.starbike.com/f...c.php?t=149513
https://forums.thepaceline.net/showp...9&postcount=23
https://forums.thepaceline.net/showp...0&postcount=40
https://weightweenies.starbike.com/f...p?f=3&t=107310
https://weightweenies.starbike.com/f...c.php?t=155657

Doesn't seem to be a mechanic setup issue, but rather a structural integrity and damage limit failure. Doesn't seem as widespread on Shimano or SRAM RD's, but it happens every once in a while nonetheless.

Good luck with the return and/or fix. Excel is usually top notch.

[charliedid]

It can't be a too short chain if running small ring. Think about how much too short it would have to be for this to be a problem.

Sorry for your troubles Crossman.

Not ridable (sorry)

[Big Dan]

Unbelievable.
Most be SRAM or Shimano in disguise.

[ColonelJLloyd]

Originally Posted by yinzerniner

Doesn't seem to be a mechanic setup issue, but rather a structural integrity and damage limit failure. Doesn't seem as widespread as Shimano or SRAM RD's, but it happens every once in a while nonetheless.

Wasn't aware of that. What is the nature of the spontaneous Shimano and SRAM RD failures? The same thing? i.e. the body of the RD just gives up the ghost mid ride?

[rain dogs]

Originally Posted by yinzerniner

Unfortunately this is a somewhat common occurrence with the carbon Campy RD's.

https://weightweenies.starbike.com/f...c.php?t=155657

Doesn't seem to be a mechanic setup issue....

This above ^^^ is 100% a mechanical set/up issue, the derailleur went into the spokes. I'm also very sympathetic of the OP's situation, that's brutal, but considering how new the bike was, I can almost assure you it was the same issue..... the derailleur went into the spokes and ripped off.

If you don't have it set up with the limit screws correct - a super common problem on a new bike, you can absent-mindedly fiddle with your lever with your finger (people do it all the time) or push on the lever to see it you have another gear etc. and it'll move the derailleur such a small amount and then it'll catch, not even right away, it'll just be right there.... spinning away and something flexes and then bam,

I've seen both happen and the spokes will look fine. However, in the link above you can see damage on the spokes.

[cmg]

Frame doesn't look compromised and the derailleur looks like it broke at a week spot, frame hanger doesn't look bent. just buy another derailleur (mid range, longer hanger) change the chain to be a little longer so not to stress the hanger in the lowest gear. If your waiting for somebody to warranty the damage your going to be without a bike for a long time. Buy the parts that broke, replace the chain and go. Had a friend break a derailleur in the same place as yours. tried to take off in a high gear from a dead stop, put all of his 240lbs on the down stroke and it snapped. Do the arm chair mechs a favor and snap a photo of the damage from the side level with the rear wheel axle. thanks

[ultraman6970]

THe main problem with carbon stuff is that you cant see cracks well if you take pictures. THe op gonna have to fill up an rma with a dealer or who ever he got the part and then they will ask for the item to be looked at.

The thing is, at least with my potenza rd, you can tell the RD wasnt crashed or anything, there's is no signs of a crash, i imagine the OP's RD is the same...that gonna have to be his lifesaver, and he needs to grab it firmly to be able to get a replacement sent to him.

I still dont understand why they went full carbon instead of leaving all that area made of metal.

[FlashUNC]

Originally Posted by yinzerniner

Unfortunately this is a somewhat common occurrence with the carbon Campy RD's.

Don't think it's fully widespread but has happened enough that you really have to be cognizant of checking the rear derailleur structural integrity before every ride.

Basically, the material around the derailleur hanger has a tendency to crack and fail without warning, either through a decent amount of use or when the chain and jokey wheels get jammed with debris. When that happens it just gets sucked right into the rear wheel and the damage is catastrophic.

https://weightweenies.starbike.com/f...c.php?t=149513
https://forums.thepaceline.net/showp...9&postcount=23
https://forums.thepaceline.net/showp...0&postcount=40
https://weightweenies.starbike.com/f...p?f=3&t=107310
https://weightweenies.starbike.com/f...c.php?t=155657

Doesn't seem to be a mechanic setup issue, but rather a structural integrity and damage limit failure. Doesn't seem as widespread as Shimano or SRAM RD's, but it happens every once in a while nonetheless.

Good luck with the return and/or fix. Excel is usually top notch.

I'd bet if the chain links were counted it'd come up short of what Campagnolo mandates in the install specs.

[Mark McM]

Originally Posted by ultraman6970

I still dont understand why they went full carbon instead of leaving all that area made of metal.

The derailleur knuckles aren't "carbon" in the same way as frames are. While sometimes referred to as "short strand carbon fiber" (as opposed to the "long strand" or "continuous strand" carbon fiber used in frames), a better description is carbon reinforced injection molded plastic. In other words, there are short strands of carbon fiber mixed in with a thermoplastic resin. It is cheaper to make the knuckles this way than to make them out of metal - and it still has the cache of "carbon fiber".

[FlashUNC]

Originally Posted by ultraman6970

THe main problem with carbon stuff is that you cant see cracks well if you take pictures. THe op gonna have to fill up an rma with a dealer or who ever he got the part and then they will ask for the item to be looked at.

The thing is, at least with my potenza rd, you can tell the RD wasnt crashed or anything, there's is no signs of a crash, i imagine the OP's RD is the same...that gonna have to be his lifesaver, and he needs to grab it firmly to be able to get a replacement sent to him.

I still dont understand why they went full carbon instead of leaving all that area made of metal.

I'm guessing you didn't see the 8/9 speed Campy RD's that had a tendency to crack at the mounting knuckle as well.

[Mark McM]

Originally Posted by yinzerniner

Unfortunately this is a somewhat common occurrence with the carbon Campy RD's.

Don't think it's fully widespread but has happened enough that you really have to be cognizant of checking the rear derailleur structural integrity before every ride.

Basically, the material around the derailleur hanger has a tendency to crack and fail without warning, either through a decent amount of use or when the chain and jokey wheels get jammed with debris. When that happens it just gets sucked right into the rear wheel and the damage is catastrophic.

https://weightweenies.starbike.com/f...c.php?t=149513
https://forums.thepaceline.net/showp...9&postcount=23
https://forums.thepaceline.net/showp...0&postcount=40
https://weightweenies.starbike.com/f...p?f=3&t=107310
https://weightweenies.starbike.com/f...c.php?t=155657

Doesn't seem to be a mechanic setup issue, but rather a structural integrity and damage limit failure. Doesn't seem as widespread as Shimano or SRAM RD's, but it happens every once in a while nonetheless.

Good luck with the return and/or fix. Excel is usually top notch.

I'm no so sure we place all the blame on the Campagnolo derailleurs. There are only images of the broken derailleur 4 of the 5 examples above. Of those 4, one is a Potenza derailleur, not a record derailleur. For one the 3 record derailleurs, the failure was the hanger, not the derailleur. And most telling, all 3 Record derailleurs were fully extended so as to be in the biggest sprocket. These seem to be setup/adjustment problems, not derailleur integrity problems.

[parallelfish]

Originally Posted by yinzerniner

Unfortunately this is a somewhat common occurrence with the carbon Campy RD's.

Don't think it's fully widespread but has happened enough that you really have to be cognizant of checking the rear derailleur structural integrity before every ride.

Basically, the material around the derailleur hanger has a tendency to crack and fail without warning...

Yep, happened to my 11 speed SR. Starting out the driveway and bang. Replaced it with a Record rd, as the portion that had broken on the SR was still made of metal.

Checked with several local shops that reported similar experiences.

[m4rk540]

Originally Posted by FlashUNC

I'd bet if the chain links were counted it'd come up short of what Campagnolo mandates in the install specs.

On Campy 12 there's one chain length for all combos and that's for optimum shifting. OP got a bad RD, no doubt.

[Mark McM]

Originally Posted by m4rk540

On Campy 12 there's one chain length for all combos and that's for optimum shifting. OP got a bad RD, no doubt.

Actually, there's two lengths: 110 links for chainstays between 405 - 415 mm, and 112 links for chainstays longer than 415 mm.

It's interesting how Campagnolo has specified exact chainlengths for 12spd mechanical shift systems; For all other systems (including 12spd EPS electronic shift systems) they don't specify an actual length, but instead specify a method to find the correct chainlength. I wonder what's different about mechanical 12spd systems?

[yinzerniner]

Originally Posted by ColonelJLloyd

Wasn't aware of that. What is the nature of the spontaneous Shimano and SRAM RD failures? The same thing? i.e. the body of the RD just gives up the ghost mid ride?

Sorry that was a typo. Meant to say "doesn't seem as widespread on Shimano and SRAM." Correcting now.

But I've had plenty of debris get caught in the jockey wheels of both my Shimano and SRAM RD's but never had one completely explode like some of the Campy examples cited. Yes, had to replace and/or bend back a few derailleur hangers and some scratched spokes, but never full on mayhem.