What are they? I realize steel is heavier...I believe it is also cheaper, may...anymore in this day and age not as readily available, at least not from the mainstream manufacturers. When it comes to performance what are the other differences. I've heard them but have never really seen them written anywhere that I can look at them and digest them thoroughly. I'm in the process right now of getting a new bike, since my current frame is pretty much toast. I know I don't have the money for titanium or carbon fiber so I'm trying to decided between steel and aluminum. I've had a Cannondale frame for 20 years so I've haven't really known anything but aluminum. Hence why I'm wondering the differences between the two of them.