Laika

My rear derailleur hanger failed catastrophically this morning, snapped right in half and the bike was brought to a complete crashing halt, though I'd been moving at a slow speed. I wasn't doing anything out of the ordinary, and am tempted to think this is a fluke and a bad part that failed. Ought I try to replace it myself, or does this indicate a more serious problem that someone wiser than I ought to investigate?

TIA for both future answers and your forgiveness of my near utter ignorance.

sydney

Do you know for sure it hadn't been bent and restraightened at some other time? Do you know for sure the derailer didn't catch the spokes or sonething with the chain catch the derailer and rip the hanger off? Hangers don't typically self destruct for no reason.

Retro Grouch 

I think that's the curse of replaceable derailleur hangers. They seem to break - sometimes with no appearant cause or warning. Buy two and stick the extra one in your seat pouch. I think that one of Murphy's laws says that if you carry a spare with you, you'll never need it.

Laika

I know it hadn't been deliberately bent & straightened, and I wasn't laying any extra funk on it. I'm pretty sure I hadn't just shifted but it is possible. At some point between the failure and my investigating and finding the problem, the chain had, in fact come off the rear hub.

sydney

I never had one break while JRA.

Retro Grouch 

I haven't either but then I don't own any bikes with replaceable derailleur hangers. I've had personal friends, whom I trust, tell me that they're had repeated derailleur hanger failures.

sydney

Makes me wonder if there was not an underlying cause, a few such mentioned above.

rmfnla

Laika doesn't mention where on the hanger the break happened. The main difference between a replaceable and a fixed is the hole(s) for the mounting bolt(s). I wonder if this could act as a stress riser..?

Yet another reason to ride steel, eh Grouch?

Retro Grouch 

Not necessarily. I don't engage in the frame material wars. While I do own three steel bikes, I also have a couple of aluminum bikes neither of which happens to have a replaceable derailleur hanger. I have a break-away derailleur mounting bolt on my Porsche mountain bike and try to concentrate on keeping my Klein road bike upright.

If you never crash, it doesn't matter. If you crash too hard, the frame is going to be ruined anyway so it still doesn't matter. Replaceable hangers only work with whatever's in between.

rmfnla

My mistake; I could have sworn that you had posted something on another thread about steel being the only proper material for frames.

Coda1

I have had two fail. The first was over ten years old and just snapped off while I was riding. The second one failed when a frozen fish got caught in the derailleur bending the derailleur and hanger beyond repair. I would expect one to last a least five years before failing from fatigue.

Laika

Frozen fish?!?

The hanger I broke snapped right in the middle. I'm starting to think that the chain somehow slipped or got seized up and that did her in.

Enthalpic

Stop putting fish in your drive train haha Really thats worth a lil story on how a fish wreaked your bike.

chemcycle

The all-too-common frozen fish in the derailler.....they really need to get that situation fixed!!

dedhed

You gotta quit biking around those ice fisherman. Was it a perch or a walleye?

fsor

It was a flying (frozen) fish...man! I thought I had hazards to deal with...

Retro Grouch 

You can't just leave us hanging like that. I want to hear the fish story!

Al.canoe

It did not fail. It's designed to break to save your derailleur and frame. It's like a fuse. Like fuses, you should always have a spare on hand. My wife and I have taken out 4 of them in the last two years. Mostly sticks, blown down by windstorms getting caught in the chain.

Some times it fails well after the occurance of the event that stressed/bent it. Having a spare allows one to periodically compare the spare with the one on the bike to see it's bent and therefore more likely to break under normal usage or is causing that shifting problem your having. I never bother doing that though.

Having had to walk a good ways out of the woods, we keep a spare with us when we ride.

Surely you can replace it yourself if you want to.

Al

rmfnla

Must be a Minnesota thing...

Coda1

Small Northern Pike

I tried to cross the river near some fish houses in snow that was about 8 inches deep and apparently the fish had been tossed aside by some fisherman and since the snow was real fluffy the fish sank into it out of sight. When I rode by it got caught in the chain and tore the derailleur off the bike.

Retro Grouch 

He must be telling the truth because nobody is creative enough to make up a lie that crazy.

KleinRider

ROTFLOL!!! that's exactly the thought I had. It must be true!