derailleur into spokes - what caused it?

[moose8]

I was going up a hill very slowly today, 60 miles into a ride, and something happened where the derailleur went into the spokes and got destroyed. I know this is usually caused by a bent derailleur hanger, but the bike and everything on it are basically brand new - less than 500 miles, and I have been super careful with everything, and there was no incident where the hanger could have bent (at least that I can imagine). It's a litespeed archon c3. The rear derailleur started skipping a little bit shortly before the incident, so that makes me think that had something to do with it, but I don't know. Since I was a ways into my ride, it seems weird the problem didn't show up earlier.

I am going to take it to my shop and have them check it out, but I am also curious if anyone here has any ideas. I don't want something like this to happen in the future, because had I been going anything but slow it seems like the frame would have been destroyed and it could have been bad.

Thanks in advance

[pitcrew]

Assuming that the limit screw was adjusted correctly (and you know that your hanger wasn't bent), then it's likely that the derailleur hanger mounting screws were loose and let the derailleur hanger/derailleur move too far inward.

[JLP]

Well on a new build, if this happens someone forgot to adjust the limit screw. If that was done correctly, perhaps the hanger got bent along the way, but usually it is just a limit screw "oops.".

[rain dogs]

yup, sounds like the limit screw.

That skipping was your chain wanting to shift up to a non-existent cog because the RD upper limit was set too high, which means your derailleur was far too close to the spokes until it went into them.

Here's hoping the frame is ok, cause the hanger would have been yanked pretty good.

[rugbysecondrow]

The bike shop used a chain to short on my bike and that happened to me. Going up a hill, slowly but the chain was under a lot of tension, I think it torqued the RD into the wheel...carbon explosion!

[zmudshark]

In my experience, things tend to loosen. This happens especially if being transported in a vehicle. Vibrations can loosen a lot of stuff.

Check your bike before every ride.

I am a retired truck driver, and 'pre-tripping' your mode of transportation can save you money, and maybe your life. Maybe we can come up with a collective bike pre-trip inspection.

Not that it's any consolation, but better men than me have put a RD into the spokes and screwed up bikes I can only dream of owning.

[moose8]

I checked the bolts on the hanger - they appear fine. Any way to tell if it was the limit screw? The rear derailleur is destroyed. I'll take it to the shop that built it and see what they say I guess, but I doubt they will say it's their fault and I doubt there is anything I could do to prove either way. I bought the frame online and paid a local shop to put it together, along with buying a bunch of parts from them.

[moose8]

The bike has only been in car for the trip back from the bike shop - every other trip has been from my house, and everything seemed ok when I checked it last night. It is sort of my dream bike, so I was babying the thing like crazy.

In my experience, things tend to loosen. This happens especially if being transported in a vehicle. Vibrations can loosen a lot of stuff.

Check your bike before every ride.

I am a retired truck driver, and 'pre-tripping' your mode of transportation can save you money, and maybe your life. Maybe we can come up with a collective bike pre-trip inspection.

Not that it's any consolation, but better men than me have put a RD into the spokes and screwed up bikes I can only dream of owning.

[Charles M]

Limit screw or chian length... Or you didnt tighten your QR and the wheel moved.

[rice rocket]

Maybe the derailleur hanger bent putting it in your car? I've bent my hanger more than I care to admit. It came bent (thanks UPS), and twice from me dropping the bike. :rolleyes:

How do you like your Archon C3 otherwise?

I have the 2010 C2, I have about 3k miles on it and I love it. I did the same, bought it online and had my LBS build it. I wasn't confident cutting the ISP myself. Not the lightest frame, but they seem pretty hardy. I've crashed mine pretty hard (once endo'd in a crit, and once getting t-boned in the chainstays by another cyclist) and it keeps on ticking. In hindsight, I wish I got the C3, it had better graphics and I'm sure I wouldn't notice the extra grams. It also came with an Ultegra 6700 grouppo, for an unbelievably low price.

[moose8]

Limit screw or chian length... Or you didnt tighten your QR and the wheel moved.

The quick release was plenty tight. My friend was like a foot behind me and said the wheel looked fine until it didn't, as he was trying to figure out why my derailler started skipping, so was staring right at the wheel. The components had been swapped off a different frame, so I'm wondering if the chain length was right for the previous frame, but not this frame (the prior frame was a cross bike, this is a road bike).

I'm also confused why it happened when it did - the bike only had three rides on it. First was 30 miles of flat, second was 111 miles with some big hills, and this third ride was 60 miles into the same 111 mile loop on what was probably the biggest hill. If it was improperly adjusted something or other, seems like maybe it would have failed earlier? Or maybe I just had not had the "right" combo of shifting earlier.

[rugbysecondrow]

The quick release was plenty tight. My friend was like a foot behind me and said the wheel looked fine until it didn't, as he was trying to figure out why my derailler started skipping, so was staring right at the wheel. The components had been swapped off a different frame, so I'm wondering if the chain length was right for the previous frame, but not this frame (the prior frame was a cross bike, this is a road bike).

I'm also confused why it happened when it did - the bike only had three rides on it. First was 30 miles of flat, second was 111 miles with some big hills, and this third ride was 60 miles into the same 111 mile loop on what was probably the biggest hill. If it was improperly adjusted something or other, seems like maybe it would have failed earlier? Or maybe I just had not had the "right" combo of shifting earlier.


I think this is it. When it happened to me, I had been riding the bike for three months.

[moose8]

It's definitely awesome except for this minor snafu. It's so light compared to my other bikes, and I may be imagining it, but doing the same rides I've done a bunch, it just seems to absorb a lot of road vibration and provide a very comfortable ride - I'm not nearly as fatigued feeling on it compared to my much heavier steel bikes, though then again I may be totally imagining it.

Maybe the derailleur hanger bent putting it in your car? I've bent my hanger more than I care to admit. It came bent (thanks UPS), and twice from me dropping the bike. :rolleyes:

How do you like your Archon C3 otherwise?

I have the 2010 C2, I have about 3k miles on it and I love it. I did the same, bought it online and had my LBS build it. I wasn't confident cutting the ISP myself. Not the lightest frame, but they seem pretty hardy. I've crashed mine pretty hard (once endo'd in a crit, and once getting t-boned in the chainstays by another cyclist) and it keeps on ticking. In hindsight, I wish I got the C3, it had better graphics and I'm sure I wouldn't notice the extra grams. It also came with an Ultegra 6700 grouppo, for an unbelievably low price.

[LouDeeter]

I'm trying to understand this. A limit screw adjustment problem would allow the rear derailleur to be closer to the spokes, true, but that would usually cause the chain to derail into the spokes as well. If the chain was still running on the large cog, then there had to have been something amiss down below, on the pulley side of the derailleur. Otherwise, you had a much tighter tolerance than I've ever seen. I have seen people run cassettes on hubs that were supposed to have a spacer between the cassette and freehub body and when they forgot to install the spacer, it created the situation you saw. I'm not smart enough to know which hubs and which cassettes require the spacer, but I'm sure someone on the forum knows that answer. I'm going to go with the missing spacer theory and not the adjustment screw.

[moose8]

the cassette was an ultegra 11-28 and the hub was a mavic k10 (ksyrium). A shop swapped the cassette off a different wheel - I have no idea if they neglected to put the proper spacer in, but I'll add that to the list of questions I have.

[LouDeeter]

9 or 10 speed?

[moose8]

9 or 10 speed?
10 speed

[SPOKE]

It was most likely one or any combination of the following:
Limit screw
Chain length
Cassette spacer missing
Derailleur hanger alignment
Jockey wheel cage bent
That's really about it unless the wheel wasn't tensioned correctly?

[Louis]

The components had been swapped off a different frame, so I'm wondering if the chain length was right for the previous frame, but not this frame (the prior frame was a cross bike, this is a road bike).

1) If you still have the cross bike you can compare CS lengths.

2) Is it more likely that a road bike would have shorter chain stays than a cross bike? I'm not sure, but maybe, in which case the chain would not be too short on the road bike. (same size frames?)

Louis

[Chance]

The components had been swapped off a different frame, so I'm wondering if the chain length was right for the previous frame, but not this frame (the prior frame was a cross bike, this is a road bike).

Not very likely if we read between the lines in your OP. You stated you were climbing very slowly up a hill which means more likely than not that you were in the small ring and a fairly large cog. IF SO, under those conditions it's hard for the chain to be either too long or too short.

If you were climbing very slowly in the big ring that's a different matter but not many riders do.

[Louis]

more likely than not that you were in the small ring and a fairly large cog.

I agree, he was most likely in the biggest cog.

However, if he was not, then it's unlikely that it was a limit screw problem. (not that you argued that it was)

[Chance]

I agree, he was most likely in the biggest cog.

However, if he was not, then it's unlikely that it was a limit screw problem. (not that you argued that it was)
Agree. My comment was only about chain length and that little ring and large cogs places RD capacity near middle so it's unlikely the chain was too short or long to have caused the problem.

FWIW Louis, this problem happened to me once in big ring and biggest cog. At the time it seem the most likely failure was that the chain got caught in the RD somehow and that pedaling chain tension wrapped the RD around. As the RD wrapped around it just happened to go into the spokes, but it's doubtful drive side spokes could generate enough force without first breaking or damaging the hub flange.

[Kontact]

Loose jockey pulley pivot screws can also cause the derailleur to get hooked by the spokes, as can one loose spoke.

[rustychisel]

any of the above, or how about the chain being improperly installed with a rivet pulling through one side plate...?

[moose8]

any of the above, or how about the chain being improperly installed with a rivet pulling through one side plate...?

This theory makes me realize I forgot to add that the chain is popped out of one rivet - I just assumed it was the chain breaking from the derailleur going into the wheel. I can't figure out how to put pictures on here, but there is a link of chain where on one side the rivet is popped out. I was in the small front chainring, and I may have been shifting into the larger cogs when it happened - I am not entirely sure.

I haven't gone to the bike shop yet, as I just didn't have the energy or time to deal with it, but I plan on not touching anything and seeing what they say. If it's the chain, is that an improper installation or just a freak defect? I certainly didn't touch the chain - it's an ultegra 6700 chain. The skipping right before it happened makes me think the chain is a good theory. Either way, I've got a trashed derailleur, a damaged carbon frame, and a busted hanger, as well as a slightly screwed up wheel now. Slightly off topic, but if it is the chain I wonder what a reasonably resolution would be? I didn't buy the bike at the shop, but in the last year I've spent at least $1000 on labor and assorted parts that certainly add up.

Thanks to everyone for their thoughts.

[Pete Serotta]

He is a very good wrench and friend. PETE (wish I could get him out to CA with me in the spring.)


QUOTE=SPOKE]It was most likely one or any combination of the following:
Limit screw
Chain length
Cassette spacer missing
Derailleur hanger alignment
Jockey wheel cage bent
That's really about it unless the wheel wasn't tensioned correctly?[/QUOTE]

[rustychisel]

If, and I stress 'if' - the chain caused the incident then that is consistent with the derailleur getting FUBAR'd and going into the spokes. A competent third party assessment should be able to tell you whether the chain caused the derailleur incident, which then caused the wheel/frame damage etc etc because the chain should show clear signs of incipient failure, even though it always seems to look like a 'chicken and egg' situation. The bike shop can then say, 'ah, but it wasn't us' or 'we'll take your warranty question up with Shimano, [or SRAM] in the knowledge that such claims are nearly always denied. In any event your satisfaction comes from the LBS if your consumer protection laws are anything like over here.

I very much doubt if the peanut gallery here is going to be able to shed much more light on your issue other than comment on some photos you might post.

Best...

[Pete Serotta]

and my wrenching non ability,,,,,, :beer: Pete


If, and I stress 'if' - the chain caused the incident then that is consistent with the derailleur getting FUBAR'd and going into the spokes. A competent third party assessment should be able to tell you whether the chain caused the derailleur incident, which then caused the wheel/frame damage etc etc because the chain should show clear signs of incipient failure, even though it always seems to look like a 'chicken and egg' situation. The bike shop can then say, 'ah, but it wasn't us' or 'we'll take your warranty question up with Shimano, [or SRAM] in the knowledge that such claims are nearly always denied. In any event your satisfaction comes from the LBS if your consumer protection laws are anything like over here.

I very much doubt if the peanut gallery here is going to be able to shed much more light on your issue other than comment on some photos you might post.

Best...

[lhuerta]

I forgot to add that the chain is popped out of one rivet

BINGO!!

If it's the chain, is that an improper installation or just a freak defect?

Could be both, but most likely improper installation...which rivet popped out? Was it the main rivet that is used during initial installation or one of the others?


Slightly off topic, but if it is the chain I wonder what a reasonably resolution would be?

Unfortunately, I doubt there is much recourse for you especially considering this was a used chain from your other ride and the many other factors that are possibly involved as well. There is possibly one small exception...if the shop re-used the original install rivet when reinstalling your chain then I would be very pissed. They should have broke your chain in a different place and then reinstalled a new rivet or used a master link/coupler.

Lastly, with regard to your der hanger...you would be amazed how many "shop mechanics" do not realize that every der hanger on a new bike needs to be aligned upon initial installation....regardless if its new.

Good luck,
Lou

[martinrjensen]

You mean you bought the components at the shop and had them assemble the bike, but you bought the bike frame somewhere else? So no master link in the chain? If there's no master link, it's likely that the link that pulled out is the one used to put it together, and if the bike shop did that there's gonna be a certian amount of liability there. I think the amount depends on store policy though. For any replacment though, if things are as it sounds like to me, your're gonna be lucky to get much of anything other than maybe some replacment parts and I'm not talking the frame either. If you do that's great. I am not saying it pays to buy at an LBS (only 1 of my 6 bikes was purchased new from an LBS, the others off of eBay) but a warantee when something like this happens is something that you usually get when your do buy from one. I guess you have to know what you are geting into.
Good luck and I will be curious as to what the LBS has to say about this. My vote goes for the chain causing the problem. This theory makes me realize I forgot to add that the chain is popped out of one rivet - I just assumed it was the chain breaking from the derailleur going into the wheel. I can't figure out how to put pictures on here, but there is a link of chain where on one side the rivet is popped out. I was in the small front chainring, and I may have been shifting into the larger cogs when it happened - I am not entirely sure.

I haven't gone to the bike shop yet, as I just didn't have the energy or time to deal with it, but I plan on not touching anything and seeing what they say. If it's the chain, is that an improper installation or just a freak defect? I certainly didn't touch the chain - it's an ultegra 6700 chain. The skipping right before it happened makes me think the chain is a good theory. Either way, I've got a trashed derailleur, a damaged carbon frame, and a busted hanger, as well as a slightly screwed up wheel now. Slightly off topic, but if it is the chain I wonder what a reasonably resolution would be? I didn't buy the bike at the shop, but in the last year I've spent at least $1000 on labor and assorted parts that certainly add up.

Thanks to everyone for their thoughts.

[moose8]

I figured out how to add a photo - you can see the chain link that popped sort of to the right of the derailleur. If any other photos would be helpful for those who know more than I do about the these things, just let me know and I can take them. Thanks again to everyone for all the ideas. If nothing else comes out of this, I want to understand what happened so it doesn't happen again.

[slowgoing]

any of the above, or how about the chain being improperly installed with a rivet pulling through one side plate...?

I agree that this can be a possibility. When anything jams between the chain and the r. der. (misaligned chain rivet, Starbucks napkin, twigs, basically anything), the tension on the chain bends the hanger and r. der. into the spokes, damaging and sometimes exploding the r. der. Happens frequently to mtb'ers. If the r. der. is damaged but dropout is still fine (unfortunately not the case for you), you can take the r. der off and shorten the chain to turn the bike into a single speed that will hopefully get you back home. Always carry a chain tool.

[oldpotatoe]

This theory makes me realize I forgot to add that the chain is popped out of one rivet - I just assumed it was the chain breaking from the derailleur going into the wheel. I can't figure out how to put pictures on here, but there is a link of chain where on one side the rivet is popped out. I was in the small front chainring, and I may have been shifting into the larger cogs when it happened - I am not entirely sure.

I haven't gone to the bike shop yet, as I just didn't have the energy or time to deal with it, but I plan on not touching anything and seeing what they say. If it's the chain, is that an improper installation or just a freak defect? I certainly didn't touch the chain - it's an ultegra 6700 chain. The skipping right before it happened makes me think the chain is a good theory. Either way, I've got a trashed derailleur, a damaged carbon frame, and a busted hanger, as well as a slightly screwed up wheel now. Slightly off topic, but if it is the chain I wonder what a reasonably resolution would be? I didn't buy the bike at the shop, but in the last year I've spent at least $1000 on labor and assorted parts that certainly add up.

Thanks to everyone for their thoughts.

I saw the pic and the chain broke. Have the LBS look at it but it is either a defective chain or an improper install(not unheard of, remember shimano chains are directional and inside/outside specific). If looking at warranty, look at the place you bought it, where the chain was installed.

6700 chains have had some 'issues'.

http://cozybeehive.blogspot.com/2010/02/shimano-ultegra-chain-failure.html

[cmg]

what kind of chain is that? I thought somewhere in the thread you mentioned it was a KMX chain. I mention this because KMX chains come with a masterlink. Shouldn't have been taking the chain apart. Finding fault is going to be difficult, too many varibles. Suspect you're going just claim this as a wash. Pull the parts that survived and plan on building another bike. The frame is a financial lost to you. i wish you well.

[moose8]

This forum is great with the collective knowledge. I googled Shimano Ultegra 6700 chain failure and my chain break appears to be far from unique, and the shearing off of the rear derailleur that results has happened to other people too. Supposedly they don't sell the chain anymore, and now have the 6701. I bought it in April when I was out with a knee injury, and stared at it until I got to actually ride my bike more recently, at which point the defectiveness of the first frame further delayed the chain getting used. The chain only had 500 miles on it (a couple hundred on the old bike, which was defective and replaced with the litespeed, and exactly 204 on the litespeed). I am a bit of a masher, too, so I don't know if that had anything to do with it.

I would be surprised if my lbs did anything wrong on the install, as I have been going there for years and they are always really good. I'll still take everthing in and see what they say, but defective chain is now the theory I'm buying into.

I saw the pic and the chain broke. Have the LBS look at it but it is either a defective chain or an improper install(not unheard of, remember shimano chains are directional and inside/outside specific). If looking at warranty, look at the place you bought it, where the chain was installed.

6700 chains have had some 'issues'.

http://cozybeehive.blogspot.com/2010/02/shimano-ultegra-chain-failure.html

[LouDeeter]

You mentioned that you "might" have been shifting into the large chainring at the time. Let's see, you're climbing a steep hill in the small ring and large cog and you decide to shift into your large chainring?? Really? Well, that is certainly going to exacerbate any tension and torque going on in the back! If the chain is even one link short, it will also rip things apart.

[moose8]

You mentioned that you "might" have been shifting into the large chainring at the time. Let's see, you're climbing a steep hill in the small ring and large cog and you decide to shift into your large chainring?? Really? Well, that is certainly going to exacerbate any tension and torque going on in the back! If the chain is even one link short, it will also rip things apart.

I don't think I said I might have been shifting in the large chainring, though I did say I might have been shifting into the large cog. If I did say that, I misspoke. I was definitely solidly in the small chainring.

Incidentally, I wasn't in the large cog, but one of the slightly smaller ones, as I just talked to my friend who was riding right behind me trying to help figure out why the derailleur had just started skipping. But, again, I may have been shifting to an easier cog when it happened - I'm just not sure on that.

Regardless, I wasn't riding my bike any differently than I have been riding my other bikes for years, which is why it seems so weird something like this would happen.

[LouDeeter]

I was mistaken. You did say large cog and not large chainring. That you weren't in your large cog eliminates the possibility of it being either the spacer or the adjustment screw in my opinion.

[oldpotatoe]

This forum is great with the collective knowledge. I googled Shimano Ultegra 6700 chain failure and my chain break appears to be far from unique, and the shearing off of the rear derailleur that results has happened to other people too. Supposedly they don't sell the chain anymore, and now have the 6701. I bought it in April when I was out with a knee injury, and stared at it until I got to actually ride my bike more recently, at which point the defectiveness of the first frame further delayed the chain getting used. The chain only had 500 miles on it (a couple hundred on the old bike, which was defective and replaced with the litespeed, and exactly 204 on the litespeed). I am a bit of a masher, too, so I don't know if that had anything to do with it.

I would be surprised if my lbs did anything wrong on the install, as I have been going there for years and they are always really good. I'll still take everthing in and see what they say, but defective chain is now the theory I'm buying into.

ASK them if when they reinstalled the chain, new shimano pin or just pushed the old pin back in. If number 2, that's why the chain broke. If number 1, defective chain.

[rice rocket]

This forum is great with the collective knowledge. I googled Shimano Ultegra 6700 chain failure and my chain break appears to be far from unique, and the shearing off of the rear derailleur that results has happened to other people too. Supposedly they don't sell the chain anymore, and now have the 6701. I bought it in April when I was out with a knee injury, and stared at it until I got to actually ride my bike more recently, at which point the defectiveness of the first frame further delayed the chain getting used. The chain only had 500 miles on it (a couple hundred on the old bike, which was defective and replaced with the litespeed, and exactly 204 on the litespeed). I am a bit of a masher, too, so I don't know if that had anything to do with it.

The chain is labelled CN-6700 or CN-6701. Read it, it's stamped right on the plates (not that CN-6701s are exempt from failure).

[moose8]

The chain is labelled CN-6700 or CN-6701. Read it, it's stamped right on the plates (not that CN-6701s are exempt from failure).
It is actually a CN-6701, though my receipt for it lists it as a CN-6700, the links are indeed stamped with CN-6701. I thought it was a 6700 based on the receipt.

It also is installed in the proper direction.

What's weird, is on inspecting the chain to try to figure out these things, I noticed another link is broken too, about a third of a chain length in front of the one I initially noticed.

[moose8]

I finally got into the bike shop today. The mechanic there, who has always been very good, said it was a manufacturing defect in the chain that caused everything - the chain was broken in a couple of places, but none near where the chain pin had been inserted. The chain only had less than 500 miles on it. He said there was nothing I could have done that contributed to it, and that it was just a case of really bad luck. He also said he has seen something similar before, but with a shimano xt chain, and shimano replaced the derailleur and chain.

This raises a whole list of other questions in my mind, such as what's the appropriate outcome? I bought the chain and frame, and a bunch of the other parts from the same online retailer where I have spent a ton of money over the years, and they always seem pretty good. We'd left it at "let's see what the bike shop says caused the problem and take it from there." The damage to the bike is as follows:

broken chain
broken derailleur
rear wheel knocked out of true (which the shop just fixed for $10)
three spokes all scratched up
chipped carbon frame (the shop said I should lightly sand the area and use white nail polish on it)(fortunately the frame itself appears to be structurally fine)
destroyed derailleur hanger

The frame itself is a replacement for a defective frame I'd purchased, so I can understand the retailer probably thinking I am just a giant pain, but at the same time I've now spent quite a bit of extra money on building and fixing the bike. And because of a bum chain I now have a frame that I can't really ever resell, though I wasn't really planning on that, but still.

I don't want to be unreasonable, but I also am just a little bummed about the whole situation. It all seems to fall in to the grey area as to what a reasonable resolution would be.

[oldpotatoe]

I finally got into the bike shop today. The mechanic there, who has always been very good, said it was a manufacturing defect in the chain that caused everything - the chain was broken in a couple of places, but none near where the chain pin had been inserted. The chain only had less than 500 miles on it. He said there was nothing I could have done that contributed to it, and that it was just a case of really bad luck. He also said he has seen something similar before, but with a shimano xt chain, and shimano replaced the derailleur and chain.

This raises a whole list of other questions in my mind, such as what's the appropriate outcome? I bought the chain and frame, and a bunch of the other parts from the same online retailer where I have spent a ton of money over the years, and they always seem pretty good. We'd left it at "let's see what the bike shop says caused the problem and take it from there." The damage to the bike is as follows:

broken chain
broken derailleur
rear wheel knocked out of true (which the shop just fixed for $10)
three spokes all scratched up
chipped carbon frame (the shop said I should lightly sand the area and use white nail polish on it)(fortunately the frame itself appears to be structurally fine)
destroyed derailleur hanger

The frame itself is a replacement for a defective frame I'd purchased, so I can understand the retailer probably thinking I am just a giant pain, but at the same time I've now spent quite a bit of extra money on building and fixing the bike. And because of a bum chain I now have a frame that I can't really ever resell, though I wasn't really planning on that, but still.

I don't want to be unreasonable, but I also am just a little bummed about the whole situation. It all seems to fall in to the grey area as to what a reasonable resolution would be.

Send the chain to shimano, USA, either thru the LBS you are dealing with now or directly. Tell the place you bought it of your actions. Ask for warranty for chain and all damage. The chain, if defective, caused the whole mess so the manufacturer of the chain should make it right. If the bike shop where you bought it is culpable in any way, they should bear some responsibility as well. Not 'grey' area at all. Cause and effect.

[Louis]

chipped carbon frame (the shop said I should lightly sand the area and use white nail polish on it)(fortunately the frame itself appears to be structurally fine)

This is good news.

I'd try to get Shimano / LBS to replace as many components as they are willing to do (going to perhaps a different model chain), do the minor frame cosmetic repair, then forget about it.

[moose8]

This is good news.

I'd try to get Shimano / LBS to replace as many components as they are willing to do (going to perhaps a different model chain), do the minor frame cosmetic repair, then forget about it.

This is what I'm thinking might be a good approach to take. I really doubt the LBS had anything to do with it, and they have never been anything but honest and fair for years, so I think I will go through the retailer I got it from and see what happens. The LBS also started with "maybe we installed it wrong" but when they saw where the breaks in the chain were relative to the installation pin, they said it wasn't an installation issue.

[moose8]

I finally got around to warrantying the chain - no one ever really seemed to figure out what happened to it, but everyone who looked at it seemed to think it was just a random defect. I sent it into Shimano and they sent me a new dura ace chain, plus cables to replace my brake and shifter cables for my trouble. REI, where I bought the derailleur, said that rather than try to deal with the derailler when warrantying the chain, I should just return it for a refund and buy a new one - I felt a little weird about this, since it wasn't REI's fault, but I went to the bike shop there on two different occasions and they said to do it that way - that it was easier than warrantying. While the whole ordeal was a bit of a pain, I was impressed with REI and Shimano in being very helpful. Realcyclist, where I bought the chain originally, was initially less than helpful and wouldn't warranty it, but instead just sent me a new chain for cost and told me to send the other back to Shimano after I made a bit of a stink about it with them. So in the end, I have no idea really what happened to the chain, but all the purchases made from a computer while stuck in bed with an injury ended up being backed by solid customer service.