pnj

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?

DannoXYZ 

Maybe your RD needs to be put on a diet?

urban_assault

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.

pnj

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.

xenologer

Could a chain too short cause issues?

pnj

It's a stock chain. I don't think it's too short.

urban_assault

Is it breaking at the same place?

Did you hit the derailer on the curb?

Design issue?

DannoXYZ 

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?

pnj

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.

pnj

RD = rear derailer. I'm a dummy.

Danno, are you a roadie?

urban_assault

Listen to Danno...I know I do.

Wanderer

Danno gives out LOTS of good info - heed his advice!

Soil_Sampler

https://northshorebillet.com/index.ph...=index&cPath=3

https://northshorebillet.com/index.ph...=index&cPath=4

pnj

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....

bikemeister

You're getting hints from the single speed master to ditch the deraillers and go with one gear!

pnj

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.

Wordbiker

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.

pnj

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...

SSBully

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!

pnj

Everyones a comedian....

Mondoman

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.

nitropowered

Get a wheelsmanufacturing/derailleurhanger.com hanger.

griftereck

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.

pnj

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...

operator

You hop a curb and the hanger breaks. Gee I wonder if that's user error or not.