You don’t need rock-hard calves, shaved legs, or a dresser full of unitards to love cycling: According to the U.S. bicycle industry, bikes designed for commuters rather than racers are the next big thing. Of the estimated 17 million bikes sold in the nation last year, over 20 percent were “comfort bikes” — up from 13.6 percent in 2000. These affordable cruisers generally come equipped with fenders, a rack, lights, and chain guards. Some call it a temporary trend and attribute it to the tight economy; some say fears about air travel are keeping people closer to home. But one of the companies behind the new commuter bikes, California-based SimpliCity Cycle, hopes it is a sign of a long-term shift in thinking: Bike commuting has long been common in Asia and Europe, but has never achieved similar popularity in the traditionally car-crazed culture of the U.S. The $4.2 billion bike industry is now stepping up its lobbying efforts to secure funding for better bike routes and road renovations to make bike commuting a more practical option.