Originally Posted by 2manybikes
Research the old aluminum bikes first made, that had tubes simliar in size to steel tubes, they had breakage problems.This is the reason for the large diameter tubes on aluminum bikes. But, you have many, many, miles to go. The newer alloys are supposedly better too.
New oversize tubes are also alot thinner.The standard diameter stuff was also wimpy, another reason for fat tubes and the additional stiffness.