I have an older adjustable type BB on a vintage frame. It's gettin a little more play in it than I like; clunks especially when spinning with less pressure on the cranks. I've looked at Sheldon's article on adjusting these and it sounds a bit tricky. I don't want to end up with ball bearings all over the place either. Am I being too apprehensive about my first BB adjustment, or should I just replace it with a modern sealed BB? I'm thinking of replacing the chain rings at the same time, too. The middle one is not quite straight and I would like a little bigger large one and a little smaller granny. Thanks in advance for your expert advice.