Philadelphia has made a mission of making bike share attractive to low- income and minority residents, trying to buck the national trend of bike-share users being white, rich, educated, and male. The city has moved bike stations into nonwhite neighborhoods. It’s used ambassadors. It’s hired a multiracial team to run the bike-share program. And it’s tried and abandoned other ideas, in an attempt to break the social stigma of riding a bike in poor neighborhoods.