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Why do I keep breaking Derailer hangers?

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Why do I keep breaking Derailer hangers?

Old 05-30-09, 09:44 PM
  #1  
pnj
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Why do I keep breaking Derailer hangers?

Giant STP, I got the bike a few months ago. I weigh less then 160 and I don't ride real hard. small jumps, manuals, etc.

I broke the first derailer today, while hopping a curb. I figured the few months of jumping caused the thing to weaken, went to the Giant dealer, paid 15 bucks for a new one and then did a few manuals, hopped a curb, jumped a curb cut and broke the new one. WTF?
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Old 05-30-09, 11:52 PM
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Maybe your RD needs to be put on a diet?
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Old 05-31-09, 12:12 AM
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Buy a couple more of them if you want to keep hopping curbs. The hanger is just doing it's job, breaking, so other parts, like your frame, don't.
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Old 05-31-09, 12:17 AM
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Danno , I have no idea what you're talking about.

U.Assault, It's a freaking mountian bike. Hopping a curb is minor riding. I have NEVER broken a derailer hanger and I have ridden MUCH harder then I have on this bike.
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Old 05-31-09, 12:21 AM
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Could a chain too short cause issues?
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Old 05-31-09, 12:22 AM
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It's a stock chain. I don't think it's too short.
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Old 05-31-09, 12:31 AM
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Is it breaking at the same place?

Did you hit the derailer on the curb?

Design issue?

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Old 05-31-09, 12:34 AM
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Originally Posted by pnj View Post
Danno , I have no idea what you're talking about.
When you hop a kerb, the bike is in vertical motion then suddenly stops. However, all the moving mass still continues in a line downward, you, the frame, all the parts. This places a high vertical load on all the parts. The wheels will face a vertical load 2-3x higher than your weight (jump up & down on a bathroom scale and you'll see how high it can get). Same with your RD, it wil pull down on the hanger with a force 2-3x its weight. Maybe the hanger is made to snap off when only 2x the weight is applied...

I wonder if RD hangers comes in difference strength versions?
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Old 05-31-09, 12:34 AM
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Both appear to have broken in the same place. It could be a design issue (I would say it is) but this bike is designed for Street Trails and Park (STP). I know many other riders are out there riding this bike hard.
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Old 05-31-09, 12:35 AM
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RD = rear derailer. I'm a dummy.

Danno, are you a roadie?
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Old 05-31-09, 12:39 AM
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Originally Posted by pnj View Post
RD = rear derailer. I'm a dummy.

Danno, are you a roadie?
Listen to Danno...I know I do.
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Old 05-31-09, 06:03 AM
  #12  
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Danno gives out LOTS of good info - heed his advice!
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Old 05-31-09, 06:14 AM
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http://northshorebillet.com/index.ph...=index&cPath=3

http://northshorebillet.com/index.ph...=index&cPath=4
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Old 05-31-09, 09:27 AM
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Thanks SS, that might be a solution.

It still doesn't explain why I would break two in one day. the second one while doing nothing....
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Old 05-31-09, 09:28 AM
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You're getting hints from the single speed master to ditch the deraillers and go with one gear!
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Old 05-31-09, 09:32 AM
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I live in the Northwest. we have mountains and I would like to be able to ride up them from time to time. Single speed isn't an option.
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Old 05-31-09, 10:39 AM
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Originally Posted by DannoXYZ View Post
I wonder if RD hangers comes in difference strength versions?
Stock hangers are often hot forged from the cheapest materials. Considering it's designed to break that's no big surprise, but some designs are too weak even for everyday riding. If you read up at derailleurhanger.com, you'll see that they have remanufactured some of their hangers from stronger materials than stock, and sometimes with slight design improvements. My apprentice with a SC Superlight bought one that has an integrated bottle opener. Pretty spiffy, and stronger than stock.

BTW, the stock hanger for the STP does look pretty weak. derailleurhanger.com's version appears to be CNC milled.

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Old 05-31-09, 11:51 AM
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the fact that it broke while coasting makes me think. What, I'm not sure...

I've ridden mtn. bikes for 8 years or so, jumping off pretty high stuff, (landing with WAY more force then I have ever done on my current bike) and haven't had an issue with the hanger before. Now, two in one day...
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Old 05-31-09, 01:29 PM
  #19  
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From the look and sound of it, it looks like you got the acronym for STP all wrong! It stands for See it, Touch it, Put it away and never ride it!
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Old 05-31-09, 01:31 PM
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Everyones a comedian....
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Old 05-31-09, 03:36 PM
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Have you talked with your Giant dealer? If there's a general design/quality issue with these hangers, they've got to have seen this before.
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Old 05-31-09, 04:22 PM
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Get a wheelsmanufacturing/derailleurhanger.com hanger.
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Old 05-31-09, 04:48 PM
  #23  
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i used to work in a bike shop
they brought out a range of mid range bikes under the Chris Boardman name.
I said I didnt like them.
But meant that they were more expensive/lightweight/ higher specced than I would ride.
I like cheaper older bikes.
Then the Boardmans kept coming back. Middle aged men that were using the Hybrid bikes to go to work were breaking the hangers. One man had 3 hangers.
The hangers were made of rubbish metal.
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Old 05-31-09, 08:58 PM
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I think these are made from the same metal that the beer I drink comes in.

I'll be checking with a dealer tomorrow but I don't have high hopes. I'm not impressed with bike shops...
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Old 05-31-09, 10:07 PM
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You hop a curb and the hanger breaks. Gee I wonder if that's user error or not.
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