Originally Posted by
tds101
Chromoly is better than aluminum when it comes to strength. Steel will bend, aluminum break. The higher end BMX bikes use chromoly steel because they're tougher.
Steel bikes are also heavier. The more likely reason is cost. The 7000 series of aluminum is strong as steel at half the weight, much better than 6061, but it probably is prohibitively expensive for this application.
I was just giving the poster some attention when I said "aluminum is best". It's best for me because it's light and I don't do tricks. I like the fact it doesn't rust, too.