I get it on each revolution. At about 2 O'clock on the downstroke of the right crank. It's getting pretty loud now, but I can't really feel it in my foot so I don't think it's the pedal. It happens on all of the three front rings, so it's not the chain/cog interface. If I pedal just with the left foot I don't get it. If I pedal just with the right foot I do. And when the bike is up on the stand of course you can't get it to make the noise! Any ideas?