The bike is a 1982 Fuji Del Ray with a stock drivetrain. After some recent maintenance I am getting clicking noises out of the cranks/bottom bracket when I pedal. The noises occur several times per crank revolution in a semi-regular pattern, only when pushing on the pedals. If I coast or if I spin the cranks without actually putting pressure on them, I hear no noises. When I push down on the right crank I hear clicks on the right, and when I push down on the left crank I hear clicks on the left. I cannot reproduce these noises by putting pressure on the cranks while holding them still -- the noises only occur if the cranks are actually turning.

The bottom bracket has a cartridge type bearing of unknown age. The retaining rings on the bottom bracket are tight and the threads are lubricated. The axle is lubricated where the cranks are set on it. The crank retaining bolts have been tightened down absolutely as hard as they will go and are also lubricated. The cranks turn smoothly and the bike runs properly other than this clicking noise. It's been driving me crazy for weeks now and I can't figure out what it is. The chain does not rub on the derailleur, and the noise is the same whether the front derailleur is in high or low gear. I do not have to actually be on the bike to produce the clicks, I can make them happen while spinning them by hand if I push hard.

I am at my wits' end here, please help!

You don't say how old the cartridge bottom bracket is or what kind of conditions you ride in, but my guess is that is where the problem lies. Even when running smoothly there could be water or dirt contamination that is causing the noise.