I remember all too well the "explosion" of motorcycle riders. It wasn't just about fuel economy though. It was a bunch of 50 yo Boomers who were successful lawyers, accountants, execs, etc. who wanted to recapture their youth by indulging in the Harley-Davidson "lifestyle." It wasn't too long afterward that the motorcycle accident stats started bulging in the over 50 category rather than the traditional 17-22 yo demographic.