We see so many aluminum bikes because you can make all kinds of variations in tubing size and weld it all together in minutes very cheaply -- Trek sells a Carbon fiber road bike with full Dura Ace and some fancy wheels for $1400 and it weighs in at less than 17lbs -- That is why the younger generation is riding aluminum and carbon fiber -- Both materials are the bike of choice in mountain biking and these are the mountain bikers who are now the road -- For better or worse we should not dismiss them they are keeping the sport alive. Sam DiBartolomeo just had 4 teeth pulled today no biking any time soon.