Thanks to Sheldon Brown and this site. I had a clunk, chunk when I pedaled my old World Sport. Checked the site and the Creaks, Clunks etc, section and bingo. Who'd a thunk the sound I was hearing wasn't coming from my crankset but my saddle! Sheldon Brown would a thunk it, that's who! Sure enough, broken saddle support. Replaced it and my "crankset noise" is gone. Thanks!