Bicycle Mechanics - intro / derailer

This is my first post, so hello all and thanks in advance for reading this.

I have a (Target) Schwinn mountain bike that has some derailleur issues. I use to bike some time ago and bought this bike as a beginner to see if I could get back into it. It’s worked, but had some problems.

My latest issue is a falling off derailleur. I was riding along leisurely on pavement and went to change gears and heard a loud bang and the bike stop moving. I looked and saw that the derailleur had fallen off (as a note, it was shifting very rough that whole ride). Here are some pics:

http://i80.photobucket.com/albums/j194/kidcharlamagne/derailer/100_0241.jpg
http://i80.photobucket.com/albums/j194/kidcharlamagne/derailer/100_0243.jpg
http://i80.photobucket.com/albums/j194/kidcharlamagne/derailer/100_0244.jpg

I contacted Pacific and Target and they won’t do anything (no real surprise), so I’ve already written it off as a loss in my mind. My question is how common is this and is it a big deal to fix? I know I need to upgrade this bike, but would like to get a season out of it. If it’s a relatively easy fix, my thought is I may as well learn something on a bike that’s already a loss.

I really appreciate any help you can give. Thanks.

It looks like the derailleur snagged the spokes as it shifted inwards. The derailleur itself is toast, plus the rear-derailleur mount on the bike's frame is twisted pretty badly. That rear-derailleur mount is replaceable, if you can find a replacement. Otherwise, it may be salvageable. You could take it to your local shop and ask them if they can straighten the mount and set you up with a new derailleur, and they'll have a vested interest in succeeding with the straightening so they can sell you the derailleur in addition to the labor for attempting it. :)

Good luck!

Oh, and if you want to try fixing it yourself, the worst-case scenario is that you break the replaceable derailleur mount. Grab it with a big pair of Channelock pliers while the derailleur's still bolted into it (to preserve the threaded hole) and bend it back so it's in-plane with the bike. When you install a new derailleur, make sure to set it up right: http://www.parktool.com/repair/readhowto.asp?id=64

Oh, and if you want to try fixing it yourself, the worst-case scenario is that you break the replaceable derailleur mount. Grab it with a big pair of Channelock pliers while the derailleur's still bolted into it (to preserve the threaded hole) and bend it back so it's in-plane with the bike. When you install a new derailleur, make sure to set it up right: http://www.parktool.com/repair/readhowto.asp?id=64

That's the way I'd go about it, but I would recommend using an adjustable wrench instead of Channelocks. It offers better control, less marring, and will prevent you from possibly bending it along an axis that isn't intended (from friction twisting parallel to the face).

If you think you can do the work yourself (the Park Tool page is a great resource), repair may make sense. If you are paying shop labor plus parts the costs go up quite a bit. I don't know what you paid for the bike, but you may wish to consider how much money you want to put into the bike.

Looks to me like someone stepped on the derailleur while the bike was lying down. Or you had a good crash. Also looks like the cobwebs are taking over that wheel. When was the last time you rode the bike before your recent leisurely ride? If the derailleur and hanger both need to be replaced (almost a certainty), and probably the chain is a little tweaked and should be replaced, then checking and truing the wheel (just in case a spoke has been weakened), plus a good tuneup to correct any other problems are in the near future; you have now gotten up to about what you paid for the bike to begin with. I think it is time to start looking for a quality used bike or an entry level new bike that doesn't come from WalMart, etc.

Thanks for all of your input.

The bike has been ridden pretty regularly over the last three months or so, perhaps 3-4 times a week for at least an hour a pop.

I’ll most likely just call it a loss and begin looking for a new and improved ride. Any beginner suggestions?