Here is the setup giving me trouble: Colnago super w/ (I think) sugino BB,campy gran sport crank/chainwheel, suntour freewheel, campy super record rear derailleur, no front der. The chain is not too worn. The LBS took a quick look at it and thought mostly it sounds fine, but there is a squeek in the second to lowest of my five gears. It happens every two or three revolutions, pretty regularly. It's just a quick squeek like "squeek squeek" or "squeek squeek squeek". The guys at the LBS said it looked like the oil was fine. The tech at the LBS used some penetrating grease on it cause he said it was the pivot on the rear der. I doubt it's too serious, but I hate the sound thinking it might become worse. I was going to re-oil my chain but they said I don't need to. Dunno what to do on this. I only switch out of this gear a few times over the 30 mi a day I go, so it's an important gear to me. =/
Also, when I'm in the lowest gear available, which is using the largest rear gear and the largest front gear (I think), it isn't pedaling smoothly. For a very split second maybe twice a revolution, the pedal feels like it lightly jerks into something, and makes a little sound. It's not a squeek, but more of a thump feeling. I think it's possible it's still trying to shift, that maybe the rear der is too sensitive. It doesn't sound like it's trying to catch on the next rear sprocket (there is none), but I don't know what it would sound like if it is trying. I can try and feather it down to the point it's shifting to a different gear, but the clunking doesn't go away.
Totally clueless here, but I'd really like to stop these issues.