Record 12 / Cervelo Failure

[m4rk540]

Originally Posted by Mark McM

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?

Good point. I meant one length for a particular frame size.

But who would be so cavalier as to run Campagnolo on a bike with super long chainstays... or super short.

[FlashUNC]

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.

Or Excel installed a chain that was way too short, derailleur put up a good fight for a few hundred miles but lost the battle eventually.

I won't rule out a flukey bad RD, but spinning along in the granny gear when there's very little tension on that knuckle leads me to think something else caused it to snap.

[oldpotatoe]

Originally Posted by huck*this

Had something similar happen to me with Campy 11. Seemed it was a faulty chain link in a KMC chain. KMC owned up to it and replaced the chain under warranty. Would not replace the Campy RD. I replaced that on my own. and being that this was on a Pegoretti the derailleur hanger stayed dead straight

That's my first thought as well...the chain failed, came apart, probably partially and 'stopped' the chain from moving thru the pulleys, pulling the rear der up and forward, breaking it..I 'suspect' that perhaps the wrench didn't join the chain properly..

[crossjunkee]

Wow, lots of good info in this thread! Thank you to everybody responding! Here's where I stand with updates.

Dan from Campagnolo made contact with me before the end of the day yesterday. Great guy, cares about his product and customers, can't stress that enough! He has asked for the derailer to mailed to him for inspection. He also offered great advice on the geometry of the frame and wheel dish. If only he could build all my bikes!

Pink Jersey went the extra mile by contacting their distributor and called me. Breakages or returns have not been reported to them. So the manufacturing is solid.

Excel has only responded by letting me know the frame might be compromised and I should contact Broken Carbon in Boulder. I did, and they responded with an estimate of $375. for the repair and they're two weeks out. All things considered, that repair price and turn around isn't bad.

I ultimately think there are four possibilities -

1. The set screws were set too close the spokes and the combination of my torque and weight going up the climb caught the derailer.

2. The chain could've also kinked in some way. I never saw a master link when lubing the chain, and it seemed smooth and fine when I wiped the lube off with a towel. I think I would've noticed / felt something out of the ordinary.

3. The chain is too short. I asked for a count of links, I doubt they will provide.

4. I bumped and bent the derailer. I didn't notice if I did. In fact, I've babied this bike more than any bike I've had in a long time.

I'm not sure where I go from here. But I miss not being able to ride and train on my new bike. I have events coming up that I'll most likely miss unless I can find a bike to borrow. I have my CX and mtn bike, but that's not the same. I want to be climbing mtn passes, riding roads, and enjoying the beautiful CO summer!

[RonW87]

If only there were a place on the internet where you could get good deals on used bikes in great condition.

[jpritchet74]

Originally Posted by RonW87

If only there were a place on the internet where you could get good deals on used bikes in great condition.

Yes, if only......

[-dustin]

any help you get from anyone will be in good faith. too much has happened between picking up the bike and the failure.

a chain being too short is likely to be noticed by the rider once the chain is in a position where it being too short will become a problem. i really doubt that was an issue.

i also believe that if you were settled into your gear combo you would've heard the cage hitting the spokes well before the derailleur got sucked in, should something like a limit screw had been off...but this isn't a guarantee.

you covered 1700ft of climbing in 8mi...it's possible that you had a bad shift that tweaked the chain, but this will be impossible to confirm at this point.

any chance a magnet could've gotten stuck to the chain? i've seen this more than a few times...magnet gets onto chain unnoticed, goes into the RD, the RD locks up and explodes.

[dddd]

I can't even imagine any frame or component defect causing this.

I've repaired quite a few bikes that came out of their shipping box with a bent hanger, including one of my own.
I've seen every sort of incorrect adjustment, at least one of which can put the derailer into the spokes.

And I've seen how some freehubs/wheels position the derailer cage closer to the spokes than others, to the extent that I have changed wheelsets because of this.

Also I've seen chains derail from either pulley, usually due to rough shifting but also from chain angle entering the cage at the lower pulley. Either scenario tends to wrap the chain over the cage plate and then pull the derailer around along the chain's path as seen in this case.

Lastly, even a small stone or other object can fly up and jam just right so as to stop the chain in the cage, resulting in the above. Such object may fly off during the mayhem that follows, leaving no evidence of such.

I would be shocked (and couldn't make the case for) any frame or parts vendor taking ownership of this occurrence. Hopefully the frame is easily fixed as I am currently doing (filling a lower carbon Giant driveside seatstay with resin). Carbon tube contusions can cause buckling-mode failure but not if the tube is filled with resin.

[Nomadmax]

I hate to say it because the cattle are already out of the barn. But, internet forums are not the first place to go when you have a failure. Most of the time it winds up being five pages of how the whole thing is your fault and there are at least ten posts the company could use to deny the claim of faulty manufacturing; even if the queries/innuendos are completely wrong.

It mostly stems from people riding similar types of bikes who believe if they disparage any claim of failure, it can never happen to them. OP, I hope you get your bike replaced in as new condition.

[m4rk540]

Originally Posted by Nomadmax

I hate to say it because the cattle are already out of the barn. But, internet forums are not the first place to go when you have a failure. Most of the time it winds up being five pages of how the whole thing is your fault and there are at least ten posts the company could use to deny the claim of faulty manufacturing; even if the queries/innuendos are completely wrong.

It mostly stems from people riding similar types of bikes who believe if they disparage any claim of failure, it can never happen to them. OP, I hope you get your bike replaced in as new condition.

The irony is that many will claim that bike wrenching is as easy as a watching a youtube video or reading a manual but then the first conclusion is user error. When newer high end components fail, I'm skeptical of UE since a home wrench will triple check every spec and a professional wrench is a professional. Unless the OP tells us he took a $2000 group to a neighborhood shop that only works on Walmart bikes, I gotta give the pros the benefit of the doubt. Cars and motorcycles are more complicated machines and the anecdata seems to show that parts fail more often than people.

[oldpotatoe]

I can't even imagine any frame or component defect causing this.

A partially broken chain could certainly cause this..not completely apart but a plate that has come off the pin, into the der, the pulleys stop turning and up and over the der goes.

[Likes2ridefar]

I was using shimano, but appears similar to yours. In my case, the master link of the shimano chain broke while barely even pedaling and damaged my frame. Fortunately not enough to break it, but lots of visible damage to my at the time nearly new carbon frame. It destroyed the derailleur, and snapped the hanger in half.

[colker]

Anyone w/ a record 12 bike shoukd at least have 2 other road bikes. That´s a rule.

[macaroon]

Probably a problem with the installation or the Campag rear mech itself.

Someone had a very similar (same?) problem on weightweenies recently

https://weightweenies.starbike.com/f...p?f=3&t=157282

[ultraman6970]

That one was electronic, even more weird to get those into de spokes. With the mechanical you can think it could happen because of problems adjusting but the electronic rd is pretty much failproof.