My Panasonic seems to me to be getting louder. I had it all tuned up and regreased when I first bought it, but the chain makes a whirring noise now when I pedal. I'm used to the quiet clicking the bike makes when I'm coasting, but the chain noise is unnerving. I had the local lbs guy look at it when he redid the tape and stem, and he said it was fine, but quiet, it ain't. Thoughts? I can't do anything to it myself, but I'd love to know if I ought to be concerned.