Failed derailleur hanger, damaged frame, restitution likely?
 

Here is the situation. A buddy of mine brought his 7 yr old Trek Madone into the LBS to address balky rear shifting. LBS tells him he needs a new rear derailleur (NFI) and that his derailleur hanger needs straightening. Repairs done, we go out for long hard ride yesterday; heading up a hill, the newly straightened hanger snaps, destroying chain and taking chunks of carbon out of the sest stays, possibly destroying the frame. Seems perhaps the bent alu hanger was cracked either by the original bend or when the LBS straightened it (or both) and that it should have been replaced rather than straightened.

So what should my buddy expect/seek by way of restitution (if any) from LBS, Trek? Warranty frame replacement, discount on new bike, sincere apology?

Can't imagine LBS or Trek would assume any liability, though trying to straighten a bent aluminum hanger doesn't seem like "best practice."

Original owner? Proof of purchase? Try running it through Trek Lifetime warranty.

What does NFI mean?
That's tuff.
Seems LBS should accept some responsibility.....but then again, how badly was the hanger bent in the first place?
Why would you need a new rear DR and was it installed?

I feel bad for your buddy!

A little back story I got a new bike 2 years ago now from my local Specalized dealer. I rode it for about a week and it shifted awful, took it in for adjusting and the they found the hanger was bent. They did the same, just pounded it straight. The very next ride the thing broke under load messing up the rear wheel badly. They fixed the wheel and everything didn't cost me a dime. Fast forward to this spring, same bike I was riding with my son who was on the "big bike trail" for the first time on his new bike and things happen he ran into me. Messed up the rear mech badly. I took into the same shop and just told them to fix whatever needed fixing assuming the frame wasn't damage. When I picked it up it was $40. They put a new hanger on it. They told me they have a repair policy because of my first event to never straighten hangers ever again, its a new hanger or they don't fix it. Hangers are really not that spendy so its a smart move on their part.

I hope your shop is good to your friend but if he is a buy and not support cyclist he might have trouble getting them to work with a guy. I support the same shop for everything, in turn they take good care of me. I get a many services for free that others might not. But a few times a year I bring in pastries too and hang out for coffee as well.

good luck...I hope they do treat him right though!!

Those derailleur hangers are replaceable for a reason.

I would straighten a minor bend, but a shop should have replaced the hanger the protect themselves from what happened.

Over seven years, a used frame accrues wear and tear.

NFI means no further info. I just don't know why the LBS thought the derailleur needing replacement. It struck me as odd, however, that they did since most worn pieces and parts would be replaceable.
The LBS installed the new derailleur after they did the hanger straightening.

That was my original thought as well, particularly since derailleur hangers can take some abuse and cracks in alu can be hard to see. But that was before I knew about the LBS attempt to unbend the alu hanger, an act that arguably contributed to the failure.

From everything I've ever read about aluminum, it does not like to be bent (i.e. no fatigue limit). Bending it to the point of permanent deformation significantly weakens it, even if it doesn't show cracks right away. Then it gets doubly weakened by bending it back to straighten it. Seems to me the LBS should have at least recognized and advised him of the risks of riding with a damaged component in that area of the bike. Instead, they tried to fix it rather than recommending replacement, weakening it further and making it more likely to fail, which it did. So now, IMHO, they have assumed at least some responsibility for the damage resulting from a faulty repair.

The bold part just makes no sense at all. Derailleurs can last for tens of thousands, perhaps hundreds of thousands of miles without being replaced. You might need to replace the jockey wheels, you might even need to r&r the RD entirely, but basically if it isn’t damaged, a RD should just keep chugging along. In contrast, an aluminum derailleur hanger is intentionally DESIGNED as a REPLACEABLE part.

So IF for reasons we don’t know, the RD really needed to be replaced with a brand new one, then OF COURSE you would also throw in a new hanger. The idea that they made him buy a brand new derailleur and then re-bent an almost decade-old hanger...that’s just idiotic.

The hanger should have been replaced. Never bend a bent one back into compliance. Weakens the material and under extreme load it can fail, as you witnessed. When we tell people that the hanger needs replacement they freak out and tell us to simply bend it back. We hand the bike back to them if we are unable to convince them of the reasoning behind the replacement policy.
Although there is no way for the shop to determine exactly what led up to and caused the hanger failure as pretty much anything could have happened between the time the bike left the shop and the time it broke, perhaps they can convince the supplier into a bro deal or crash replacement deal on a replacement frame.

FWIW, the hanger broke the day after he got the bike from the shop after only 25 miles of riding.

You guys recommending hangers be replaced for minor bends, obviously never worked in a shop.

1) Hangers are realigned on a daily basis at the shop level, for non excessive bends
2) I can remember one maybe two times we replaced a hanger for a minor misalignment -- in 10 ******g years
3) There is NO way to determine once the bike has left the shop who was at fault, the customer aka YOU could've bent it anytime it left the shop. Some hangers, on cervelos or other manufacturers are EASILY bent.

And just to remind people, I worked in a high end road shop that dealt with these kinds of bikes, on a daily basis.

If you were a good customer the shop might take on the full repair cost, but there is ZERO way to know who was at fault here.

Means absolutely nothing.

Could be coincidence, maybe it's not. No way to prove either.

Joke.

Another joke.

RDs wear out. You weren't there you don't know what state it was in. Perhaps it was worn out enough to have play in the pivots, maybe the spring was losing tension and binding.

There is NO reason to replace a derailleur hanger, "just because".

The hanger is designed to be replaceable so that when it breaks it doesn't take the ******g frame with it. Just because its replaceable doesn't mean you replace it for all the nonsensical reasons that have been put forth in this thread.

This thread grates.

I have to wonder if the rear derailleur hanger would spontaneously fall off while doing a hill climb.

My guess is that the cyclist had chain suck, or something similar, and rather than letting up on the pedal stroke, instead ripped the whole rear end off of the bike.

A really bad situation for all involved. Whatever you do, be patient and reasonable - try to figure out the options.
Good way to start with the LBS: "could you determine what caused this" - explaining the scenario when it had happened, shifting pattern, chainring combo - all the info.
Bad way to start: "RD hanger you straightened just snapped and ruined my frame" - even if that turns out to be the case. I think it's never too late for that, if the LBS is being jerks and turns out it was their fault.

From both a customer and bike shop perspective/point of view.
And, with an assumption that both the customer is being honest in their claims and the bike shop is being professional:

A RD can have lots of play in the pivots, or have bent cage, or something third, which warrants replacement recommendation.

The fact RD hanger needed straightening means it probably got hit some time - with the RD usually taking the blow as well in those cases.

RD hanger, even an aluminium one can be straightened - then inspected for any cracks. From my experience, I've learned that replacement is the safer bet, but I did straighten quite a few - with no problems. Always warning the owners of the still higher probability of it cracking, suggesting them to at least check on a weekly basis, especially in the first few months. Checking myself initially, right before and after the straightening procedure. Still, not all the people are reasonable, so it is safer to replace. Though straightening is cheaper and sometimes a fitting replacement hanger isn't easy to source.

Inspect the crack on the RD hanger. Fatigue induced crack has a part that is "finer", with some oxidation as well, with the last part (when it finally snaps) being more jagged. If the entire broken area cross section is similarly coloured and jagged, then it was most probably not fatigue induced, but snapped by force (chain getting stuck etc.). The best picture of it I could google:

https://qph.fs.quoracdn.net/main-qim...45df3804952f4a

I'd inspect the broken part. If it cracked recently, after straightening, and looked like a fatigue induced one (as shown in the linked picture), it would be on me - should have inspected it better.
Frame replacement (probably taking a credit/loan, with the cost of new carbon frames and the wages in my country :) ).

If the break line did not look like a fatigue induced one - bad luck for the customer, sorry to say. Though I make sure to notify them of the risks involved with straightening aluminium RD hangers before doing it.

The fact breakage happened while riding up hill would have me consider the possibility of poor shifting, chain getting stuck or something similar.

Seat stay cracking/twisting under the climbing load could put the chain at an awkward angle, then snapping the RD hanger - this is a long shot, but also worth inspecting as a potential problem cause. Again - I'd check the crack intersection for any oxidation.

Thanks everybody.Quite a range of perspectives in this thread.

Could be the bike shop screwed up, could be the hanger was damaged some other way, could be bad shifting and stuck chain on the hills we were riding caused the damage. All I can say for certain is my buddy did not wreck in any way that could have damaged the hanger between the time the shop worked on the bike and our ride. But it was an intense ride with one major climb ride and several other hills in the first 25 miles so poor shifting could be at play.

It certainly will be interesting to see how the shop responds. Its a small and growing chain in an area with a number of other shops. My buddy had taken the bike to the location near his work rather than the the one in our neighborhood. He is now dealing with the neighborhood one, which is dealing with the other location on his behalf. The shop is not a Trek dealer, so a any kind of discount on a replacement Trek frame is probably not an option. But I would be surprised if the shop goes with the “user error” option and offers nothing by way of compensation given that its a crowded marketplace around here and mechanic error is at least a possible contributor to the problem.

This is one of those things. It was an expedient fix for a part that doesn't take well to bending that is hard to source. That the failure trashed the frame--I'd ask Trek about crash replacement at least....but placing liability on the LBS is a hard one from what I've read.

Well "replaceable" in intent...if not practice. They're almost always special order items, and for any bike more than 5 years old good luck ever actually finding a replacement IRL.

I don't know how chummy Trek is about warehousing RD hangers for 7 year old MY bikes...but I suspect OP got told that it either couldn't be gotten, or that it would be August before it arrived, and bending the RD hanger back was more expedient.

I absolutely think there is financial liability after your buddy trusted the judgment of the LBS. Same as there would be if a car repair resulted in a similar disaster. Just a heads up about what you read here: There are owners of lbs and so on, on here who naturally want to disclaim liability and do so loudly and vigorously, so read all replies and think them through. I would have him write a courteous letter to the LBS and to Trek first, with specific info and pictures. I would then gather evidence and go to small claims court if no restitution was forthcoming. He is welcome to PM me if he needs an overview of how to go about small claims, but I think that the letters may bring some response.

https://derailleurhanger.com/

Update, the LBS is offering a replacement frame. Unkown yet what specific frame they deem as comparable to a 7 yr old Madone. They are Specialized, C’dale and Giant dealers but not Trek.

So? They don't have everything. And the further back you go, the more hit-miss it is. Same as OEMs. Their cut off line seems to generally be about 2010-2011.

For example my 2002 BMW blue Kestrel Talon I have hanging up--I'm never finding an RD hanger for it again, in all honesty, should I ever have the urge to build that frameset up again.