This is the Campagnolo mess when your rear gear hanger breaks

Discuss light weight issues concerning road bikes & parts.
AJS914
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by AJS914

Do you think it was chain suck?

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Lewn777
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by Lewn777

I've had this happen twice with rental bikes. Bikes get bashed around and not treated properly also the rental companies hate chainging chains, sprockets and cassettes as that cuts into their profit margins. SRAM systems shift well when they are properly looked after, but they can fail badly if mistreated.

by Weenie


c60rider
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Joined: Mon Feb 27, 2017 11:12 pm

by c60rider

Lewn777 wrote:
Sun Mar 17, 2019 11:21 am
I've had this happen twice with rental bikes. Bikes get bashed around and not treated properly also the rental companies hate chainging chains, sprockets and cassettes as that cuts into their profit margins. SRAM systems shift well when they are properly looked after, but they can fail badly if mistreated.
My ocd attention to keeping bikes in meticulous condition contradicts this assumption.

c60rider
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by c60rider

AJS914 wrote:
Sat Mar 16, 2019 3:50 pm
Do you think it was chain suck?
I'm guessing this is all it could have been. The original hanger seems to be a much tougher material than the wheels manufacturing one. Maybe the wheels one was designed to fracture at the slightest drive train issue as a protection to the rest of the drive train/ bike whereas the old one wasn't. Who knows.

alcatraz
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by alcatraz

Isn't it interesting that this happened after a hanger swap? Is it possible the dropout got damaged during the swap or alignment thereafter?

If the hanger was aligned only once with none or inadequate skewer tension the force goes into the dropout.

Or perhaps if the hanger bolts were overtightened.

Is it a carbon dropout?

Raoul at Luescher Technik I think would say that many carbon dropouts are metal designs done in carbon = not optimized for carbon.

c60rider
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by c60rider

alcatraz wrote:
Sun Mar 17, 2019 3:11 pm
Isn't it interesting that this happened after a hanger swap? Is it possible the dropout got damaged during the swap or alignment thereafter?

If the hanger was aligned only once with none or inadequate skewer tension the force goes into the dropout.

Or perhaps if the hanger bolts were overtightened.

Is it a carbon dropout?

Raoul at Luescher Technik I think would say that many carbon dropouts are metal designs done in carbon = not optimized for carbon.
The fact it happened so quickly after a hanger swap on a bike that had worked perfectly for 7 years is why I wrote the thread in the first place. The new hanger had no damage to it. The only stress, as such, was an initial alignment with the Park tool. I used threadlocker on the bolts just so that they didn't need overtightening at all. I think they're 2mm allen keys so fairly small which logically limits the tightening force you can put on them but it didn't break across those. I've no idea about the dropout material but they're nothing like the C60 I have so I would guess they're not carbon.

Karvalo
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by Karvalo

c60rider wrote:
Sun Mar 17, 2019 2:05 pm
The original hanger seems to be a much tougher material than the wheels manufacturing one. Maybe the wheels one was designed to fracture at the slightest drive train issue as a protection to the rest of the drive train/ bike whereas the old one wasn't.
How can you tell, since the Wheels one is already broken? Did you put them both in a vice and try bending them, or what?

WMFG hangers are quite a bit stronger than the average OE spec, though of course OE spec hangers vary massively in toughness.

c60rider
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by c60rider

Karvalo wrote:
Sun Mar 17, 2019 5:51 pm
c60rider wrote:
Sun Mar 17, 2019 2:05 pm
The original hanger seems to be a much tougher material than the wheels manufacturing one. Maybe the wheels one was designed to fracture at the slightest drive train issue as a protection to the rest of the drive train/ bike whereas the old one wasn't.
How can you tell, since the Wheels one is already broken? Did you put them both in a vice and try bending them, or what?

WMFG hangers are quite a bit stronger than the average OE spec, though of course OE spec hangers vary massively in toughness.
What else would you do for a gear hanger alignment other than try to bend them? A vice isn't required.

Karvalo
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by Karvalo

Ok tough and stiff aren't the same things, and resistance to slight bending and resistance to fracturing aren't the same things.

Regardless, usually WMFG hangers are stiffer than OE hangers.

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Lewn777
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by Lewn777

c60rider wrote:
Sun Mar 17, 2019 2:01 pm
Lewn777 wrote:
Sun Mar 17, 2019 11:21 am
I've had this happen twice with rental bikes. Bikes get bashed around and not treated properly also the rental companies hate chainging chains, sprockets and cassettes as that cuts into their profit margins. SRAM systems shift well when they are properly looked after, but they can fail badly if mistreated.
My ocd attention to keeping bikes in meticulous condition contradicts this assumption.
No, it doesn't.
IMHO that it's much more likely to happen with worn chains, chainrings, cassettes and bent hangers. Still it can happen occasionally when there's nothing obviously wrong. One dry link that can cause a some odd chain flex or a foreign object like a small rock can get flung up and jammed around the jockey wheels.

Your assumption that the hanger 'just snapped' is totally bogus. Obviously something has malfunctioned otherwise why would there be frame damage too? I'm not saying it's your fault though, it's just one of those things that can happen every 20,000-30,000 kms. Plenty of people carry spare hangers for this exact reason.

Gary71
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Location: Brisbane Australia

by Gary71

This is happened to me 3 times in as many years.
The first was on my Cervelo S3. i was dancing on the pedals going up Noosa Dr past the RACQ resort. No apparent reason. The Cervelo had never been in a fall or crash, knocked or scratched - the part just failed.
The 2nd was on my titanium bike. Destroyed my RD, Cassette, wheel and chain. The wind blew it over on the expensive side during a refuelling break and taking in the views of water - so I put the failure down to the RD hanger being weakened by dropping on its side………, and then while i was standing up on the pedals ascending a steep pitch, it failed under load.
The 3rd was on my CAAD12 disc - less than 6 months after I bought it and it would have done under 600kms and it failed ascending a steep hill, again whilst standing on the pedals. By this time I got the sh!ts and asked the LBS where I bought it to replace all the parts that were damaged under warrantee
My take on the RD hanger scenario I’ve put down to 3 things. 1. Some RD hanger designs are better than others (they are inherently weak through the design). 2.The hangers these days are made out of AL mix that is too soft. It is more than likely they all come from a mass produced factory that makes RD hangers for most of the production bikes out there. Their production processes aren’t great and the occasional batches have impurity’s in the melt and or the QA doesn’t exist and its a lottery to what you get. And 3. I am hard on hangers as i like to be able to stand on the pedals going up hill and not hesitate to change the RD gear to an easier one (bigger cog), this puts a lot of stress on the RD’s and over time they fatigue due to point 1 and 2.

I can say my Cervelo and CAAD12 was never dropped, bumped or miss aligned during its short tenure prior to the RD hanger failure. I think manufactures have moved too far to the left and the RD hangers are barely 'fit for purpose' these days.

I have changed my shifting practice and try not to change gears when I am standing on the pedals hammering it up hill….., but I only do that because i don’t have faith in the Rd hangers these days. In this modern age of design - we should be able to hammer it up hill and change at will…….. Give me the faith of a steal bike with a brazed on RD hanger any day !

Q. Does anyone out there know of someone who is making Carbon RD hangers? They could be strong on one plain and weaker laterally if required?
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mattr
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by mattr

One of the early Cervelos (can't remember which one) had a hanger that would pretty much just bend under shifting load. Could have been one of those.

Also, if you want a stiffer hanger, get something from Wheels manufacturing or BETD. They are all CNC machined from billet stock.

Karvalo
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by Karvalo

Gary71 wrote:
Tue Mar 19, 2019 9:03 pm
This is happened to me 3 times in as many years.
Once is happenstance, twice is co-incidence and three times is enemy action.

I agree that it would probably be better if hangers were much stronger, even if it lead to more frames being damaged by initial impacts, but if you've had three three different hangers on three different bikes go in a relatively short time then it is definitely your fault. They're not that bad, and you're not that unlucky.

c60rider
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by c60rider

I come from an era before gear hangers were separate to frames and I only thought they had been invented in case you stripped the thread of an existing hanger! I don't understand why we really have them if they're going to break like that. What are they preventing or protecting? Have components and frames just become that much more delicate that just being used normally can break them. Are the fine tolerances that gears are working under pushing things too far to the extreme? Rebuilding my old steel bike couple of years ago it certainly seems so. I'm not sure SR11 components I'm buying of late are going to be as durable as those bits I'm using that are 30 years old.

ND4SPD
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Joined: Sat May 19, 2018 4:10 am

by ND4SPD

Happened to me on Cannondale Synapse Hi-MOD with Shimano Ultegra 6800:

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by Weenie


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