Did I ruin my chain?
I bought a Raleigh C500 late December 06 and have been riding it 4 times a week since (maybe 5-15 miles per ride). For the last month I took off the front derailler to see if an 8 speed would work for me (considering a Nexus 8). I just put the front d. back on and did a 20 mile ride. I began to get a noise everytime the right crank started to come over the top. I thought I just didn't have the d. adjusted properly and it was hitting the front cage. When I got home and oiled it I saw that it wasn't hitting the cage it looked like it was "twisting" or moving "sideways" a little. It did it on all 3 chainrings. Any suggestions on what may be causing it, or did I mess something up or just worn the chain out?
Hard to tell without seeing it. One possibility is that a rivet has come loose on one plate, allowing the chaing to deflect, but I would expect total failure in very short order. I have seen inexpensive chains be "snaky" but not any acquire that problem after use.
You may have a twisted chain link. That's fairly common. If that's the case the quick dirty solution is just to remove the twisted length. The "A" answer is to replace the whole chain since removing the link will probably make the chain 1" too short for your drive train.