What is Chromoly? From what I have read it is lighter than steel and I am guessing heavier than carbon or aluminum. Is that correct? What I read said is that they use less making the frame lighter and more flexible.
Steel is naturally more flexible than aluminum and definitely heavier than aluminum or carbon, but it does offer durability over both. One thing to remember, however, is that cromoly is not like stainless steel. It will rust very easily so any exposed metal should be properly protected.
No, that's not true, steel is stiffer than aluminum. Aluminum bike frames generally have a reputation for being stiff, but it's because they're usually built with larger diameter tubes. Steel frames generally have a reputation for being somewhat springy, but it's because the frames are usually built from smaller diameter tubes. As a material, steel is stiffer than aluminum, however-