Ohh... I hate loose cranks. Three piece, or cottered. Because the moment that I flip them over and feel a movement, I know the loose crank is probably toast. I've lost too many cranks that way, and it makes me very sad every time.
However, in my experience, birdie noises almost always come from the jockey wheels on a bike. (Is the Sports a 3-speed? If so, I'm an uber-fail.) But in my brain, bike+birdsounds=rd wheels.
-Nick