Originally Posted by
009jim
Steel is not always heavier. It has a higher density and a higher strength. For the same cross sectional area steel is generally many times stronger than aluminum. So generally, for the same strength, steel will be lighter than aluminum. However, if you compare low grade steel with high-strength aluminum, the aluminum will be stronger - but it's not a fair comparison. A further consideration is toughness and ductility - both of which are desirable for safety. Steel is much tougher and more ductile than aluminum. All of these reasons are why I like the Chrome Moly steel forks for my bike.
Steel...the alloy of iron, carbon and other trace elements...is
always heavier than aluminum for a given volume, which was the point I was making on page one. You are correct that you can use less material to make a bicycle because of it's greater strength...also something I pointed out. However, if you are smart about how you engineer aluminum, you can use much less than 3 times the volume of aluminum to get a bicycle that is as strong as a steel frame, so aluminum frames are usually lighter than a comparable steel frame. But, for a fair comparison, you can't compare low grade aluminum to high grade steel either.