Dangling Chain and Derailer

Replaced a back tire tube this weekend and my rear derailer came off the frame. Reattached it and now my chain is way to loose and not catching the rear gears. Any help?

You did not put the wheel in the frame correctly ...

To state what should be obvious, wheel goes INSIDE the chain's continuous loop ...

thought i had it fixed but the same thing happened. chain keeps falling off and derailer isnt holding it in place. the chain isnt reaching the gears.

Looking at the chain coming from the chainrings (where your cranks are), it needs to run from the top of the chainring to the top of the cogset (on your rearwheel), around in the back, then above the upper little wheel on the derailleur, around that, go between the two little wheels, and come out at the bottom of the bottom wheel, from where it returns to the bottom of your chainring.

looks like the chain is running right its just not catching the gears and is just dangling now. the derailer seems to be moving too much. ive never been able to move it around so easily.

I have no idea what the problem could be, maybe a photo would help

here are a couple of photos of how the chain should be routed the second photo is of how the chain fits through the rear derailuer and cogs.

hope this helps
this is the first time that I have tried to insert a photo hope it works




[IMG]file:///C:/Users/donaldchong/Pictures/2009-09-14/560.JPG[/IMG]

thank you for the pic. the chain isnt hitting the second little wheel of the derailer and the chain is just kind of dangling. theres no tension like there should be.

Are you saying there is no tension in your derailleur arm? With the chain off the chainring, does the derailleur arm fold all the way back (bottom wheel towards the rear of the bike)? What kind of a derailleur is it? Could the spring that normally provides tension be broken, or loose?

Yes the derailer is folding back when its off the chain ring. Its never done that before. Ive always been able to move it when I take the tire off but it would kind of spring back into place. Maybe I do have a broken spring. Would this mean getting a new derailer?

If the derailluer is springing to the back, it appears to be working properly.

can you provide a photo of the drive train?

the derailer was broken. getting a new one. thanks for your help