I was admiring the heaps at the Goodwill store and they have an old Huffy 15 speed for $22. It's got a triple front 1 piece crank, probably mid-late 70s based on the giant stem shifters, suicide brakes and center pull brakes. What are the odds that the triple 1 piece crank on this bike is the same size as my Schwinn Continental double crank I have now. Even the frame tubes looked similar in diameter, so may be the deraillers would move as well. Is this a cheap opportunity to scarf parts off a Huffy and upgrade my Schwinn to a triple, assuming its still there in the morning?