On my way home yesterday the rear derailer gears started shifting badly (minor hesitations, noisy). So I figured I would tighten the cable at the rear derailer by turning the adjuster barrel counter-clockwise a half turn. I did it. Made it a little worse, so I turned it back...and before you know it, I can't remember how to get the adjuster barrel back to the original position I started from, though the gearing seems to be better now, but still not how it usually is.
Any advice on how to get the gearing smooth again?
Also, I notice my derailer wiggles ever so slightly on the mount at the frame (~ 16th inch at the mount point), even though the derailer mounting bolt is tightend all the way. Is it supposed to wiggle a little even though it is bolted down tight?
I have a Shimano Sora on my road bike, and the chain is still ok.
Thanks so much for any help.