I remember the day: a sinewy bicycle messenger skillfully weaved through honking automobiles and came to a stop at the traffic light in front of me. But instead of dropping a foot, he balanced high above his fixed-gear pedals for nearly a minute, his crossbody bag bulging against the urgent deliveries within. That was ‘90s San Francisco, when anyone could tap into that free-wheelin’ zeitgeist by wearing a messenger bag — only conformist dorks wore backpacks.
Switzerland-based Freitag…