Record 12 / Cervelo Failure

[tomato coupe]

Originally Posted by jtbadge

It's the same thing, though. The limit wasn't set, this ride was the first time it was tested, and it caused a failure. Surely the set up was to blame, but there's no way any shop would warranty this 500 miles down the road.

I was simply responding to your theory of a very specific failure mode that was not supported by the OP's account of the incident.

[crossjunkee]

Originally Posted by yinzerniner

What OP stated is that he was not shifting, but rather that he had shifted into the 32t.

So while the improper limit screw didn't push the RD into the spokes when he shifted down into the 32t at that exact moment, later when he was JRA the combination of "torgue (sic), frame flex, and limit screw" caused the RD to go down into the spokes.

That's correct, no shifting. I was in the 32 for at least a mile, maybe two. My suffer score just turned to red as indicated by the red number in my original screenshot. The climb was getting steeper, but wasn't hard. I can climb Squaw in my big ring. This the Triple Bypass is a "fun" ride and I was with friends.

[tomato coupe]

Sorry if this has all been covered, but a couple of questions for the OP:

1. Was the derailleur hanger bent?

2. Were the spokes really undamaged as stated in an early post?

3. Is Campy 's conclusion about the mis-adjusted limit screw based on an examination of the rear derailleur only?

[crossjunkee]

Originally Posted by tomato coupe

Sorry if this has all been covered, but a couple of questions for the OP:

1. Was the derailleur hanger bent?

2. Were the spokes really undamaged as stated in an early post?

3. Is Campy 's conclusion about the mis-adjusted limit screw based on an examination of the rear derailleur only?

1. Was the derailleur hanger bent? It is "slightly" bent now. I don't know if it was in this condition prior to the ride. I did wash the bike and lube the chain the night before and everything was fine.

2. Were the spokes really undamaged as stated in an early post? The spoke that caught the derailer was scratched and scuffed, not bent. The wheel was still dead true. The spoke has been replaced.

3. Is Campy 's conclusion about the mis-adjusted limit screw based on an examination of the rear derailleur only? They asked me a lot questions and and examination of the derailer. I don't know if they spoke to the shop. The chain was fine and had the correct amount of links. Dan and team are excellent mechanics, I trust them 100%. His replacement is now on the east coast. I want to say they thought the hanger should've snapped before the derailer broke, but I can't remember.

[tomato coupe]

Originally Posted by crossjunkee

The spoke that caught the derailer was scratched and scuffed, not bent. The wheel was still dead true. The spoke has been replaced.

The spoke damage may have been incidental. I don't think you would escape with just one scratched spoke if shifting into the spokes was responsible for breaking the rear derailleur into two pieces.

[The hanger] is "slightly" bent now. I don't know if it was in this condition prior to the ride. I did wash the bike and lube the chain the night before and everything was fine.

[Campy] asked me a lot questions and examination of the derailleur. I don't know if they spoke to the shop. The chain was fine and had the correct amount of links. Dan and team are excellent mechanics, I trust them 100%. His replacement is now on the east coast. I want to say they thought the hanger should've snapped before the derailleur broke, but I can't remember.

Yes, derailleur hangers are kind of like fuses -- they are meant to bend or break before something more valuable breaks. Given the catastrophic damage to the rear derailleur, it is a bit odd that the hanger was only slightly bent. That, combined with the minor spoke damage, leads me to think that you just got unlucky and got a bad derailleur. It may have failed on it's own, or slight contact with a spoke may have been enough to cause it to fail. Either way, I think the derailleur must have been faulty.

I give Campy credit for replacing the derailleur, however, I think they were peddling (pedaling?) a little bit of BS when they stated the limit screw was at fault. I don't think they can draw that conclusion by an examination of the derailleur only. I hate to be cynical, but I think they played this well -- they made you happy while deflecting the blame.

Sorry to hear you missed some good rides, but glad to hear you like your new bike.

[azrider]

Originally Posted by Ozz

If only someone made something to keep the chain from getting to the spokes....you know, like a spoke protector?

[beeatnik]

Rear derailleurs in spokes are so weird.







4% grade, shift from center of cassette, 3 beach cruisers in the vicinity. Blame Ciclavia.

[charliedid]

Originally Posted by crossjunkee

This. Squaw Pass was the first time in 400 miles that I shifted to the 32. Combined torgue, frame flex, and limit screw not properly set equaled disaster. As I understand the DT hubs have a larger flange that makes the spokes closer on 12 speed. Be careful and double check clearance on builds running DT240 hubs and Campy 12 speed. They're still 100% compatible, but the clearance is close.

Got it.

[charliedid]

Originally Posted by tomato coupe

The spoke damage may have been incidental. I don't think you would escape with just one scratched spoke if shifting into the spokes was responsible for breaking the rear derailleur into two pieces.



Yes, derailleur hangers are kind of like fuses -- they are meant to bend or break before something more valuable breaks. Given the catastrophic damage to the rear derailleur, it is a bit odd that the hanger was only slightly bent. That, combined with the minor spoke damage, leads me to think that you just got unlucky and got a bad derailleur. It may have failed on it's own, or slight contact with a spoke may have been enough to cause it to fail. Either way, I think the derailleur must have been faulty.

I give Campy credit for replacing the derailleur, however, I think they were peddling (pedaling?) a little bit of BS when they stated the limit screw was at fault. I don't think they can draw that conclusion by an examination of the derailleur only. I hate to be cynical, but I think they played this well -- they made you happy while deflecting the blame.

Sorry to hear you missed some good rides, but glad to hear you like your new bike.

I agree with this.

[charliedid]

Originally Posted by azrider

I'm working on a line of bespoke pie plates made from compostable recycled espresso cups.

I'll send you a beta version when my supplier gets back in touch.

[IJWS]

So is the frame ok or is it damaged? $375 to get a backup bike isn't the worst deal (whatever you paid for the bike in the first place + $375 is a bad deal I suppose).