Possibly stupid question: I am getting a recurring "clunk" and the feeling that there is too much play in my pedals (on clunk per pedal revolution, and a feeling that there's some side-to-side flex, although when I grab the pedal and wiggle it, it doesn't seem to move). I have had the bottom bracket tightened, which stopped the noise briefly, but now it is back and is accompanied by a buzzy rattle that seems to be resonating through the frame and front fork. Could the bracket or the bearings be going? My LBSs don't seem to be much help - one told me my cassette was worn out, one tightened the bracket, and a third denied hearing any noise at all.
(The bike had a full tune up last month that also temporarily stopped the rattle/clunk/whatever.)
Bike is a 2006 Norco Pinnacle, very basic but I was really wanting to get more out of it than this. It has maybe 500kms on it altogether. It is my commuting vehicle.