Bicycle Mechanics - Can I bend this back into position?

The part holding the rear derailler to the frame is bent, but I think the derailler arm is ok. It's bent enough that no pedalling is possible in any gear. I'm concerned that replacing the part will end up being very expensive, and that it would be better to spend the money on a new bike.

So my question is this, is it possible to bend this piece back into alignment, so that the bike will shift smoothly? Or will it never again work properly?

Uh... you might want to tell us what the material is...

If it is steel you should be able to bend it back. If it is aluminum it will likely break off if you try. If it is aluminum hopefully it is a replaceable hanger. The bike shop said the replaceable hanger for my Cannondale was about $20. Since I am a machinist I just made my own.

Uh... you might want to tell us what the material is...
Ha, yeah, good point. You know what, I don't even know off-hand. It's a Diamondback Outlook. Which material is cheaper? That's probaly what it is.

If it's only $20, that ain't bad at all.

I guess I was wondering if, in theory and assuming the material is pliable, you could ever bend it back into a proper alignment, or if it would always be a noticably off when shifting.

Even if it is aluminum it can be bent back some. Steel can be bent back a lot more, though.

Ha, yeah, good point. You know what, I don't even know off-hand. It's a Diamondback Outlook. Which material is cheaper? That's probaly what it is.

If it's only $20, that ain't bad at all.

I guess I was wondering if, in theory and assuming the material is pliable, you could ever bend it back into a proper alignment, or if it would always be a noticably off when shifting.Ever heard of a refrigerator magnet and how to tell a steel bean can from an aluminum beer can? A bent hanger can be aligned. Problem is an aluminum one can't be bent near as much as a steel one without breaking or serious weakening.

Any decent bike shop should have one of these:

http://www.parktool.com/images/tools/DAG_1i.jpg


And they'll let you know if it's a bend or replace kind of repair.

If you decide to try bending it back yourself, don't unbolt the derailleur. If that bolt hole isn't full it can distort during the bending process and then you won't be able to get your derailleur back on.

Shifting will always be "off" unless you use the proper tool to straighten and re-align the hangar. If it is a bolt on hangar and it is as bad as your post would imply then it is best to just replace it. You may still need to have the new one aligned after it is mounted on your frame.

Enjoy

Thanks for the input guys. I tried the magnet, and the piece is aluminum. So I'm going to have it replaced, no biggie I guess.

Aluminum responds better to fast bends rather than slow ones...so that means hit it with a hammer rather than taking your hands and slowly bending it. It is less likely to break if it is bent fast.

Um, not really. Either way embrittles the metal. The most precise way to do it if you don't have a shop handy is to unbolt it and put a large adjustible wrench on the portion of the dropout just below the threads(frame side). The wrench has flat faces, which will not mar, and the postion will not cause thread distortion.
The ideal is certainly the full tool, but I have used the wrench for years without problem.