Bicycles allowed young men and women to tool around the countryside unsupervised, and relationships between the sexes grew more casual and spontaneous. With a bicycle at her disposal, a young woman could also venture forth in search of work. Small wonder that Susan B. Anthony said of cycling, “I think it has done more to emancipate women than any one thing in the world.”
Today, bicycles are viewed as a solution to a host of social ills: air pollution, global warming, obesity, traffic jams. According to Statista, an online data repository, 67 million Americans said in 2014 that they had ridden a bike at least once in the past year, up from 47 million in 2008. Almost 5 percent of Americans commute to work by bike, compared with 1 percent in 2000.
Angier has the bike hype down, but it's not clear where she got the 5% figure, even after looking at the site she links---and I'm not about to pay $600 for a year's subscription to find out where they got it.
The Census Bureau (page 3) says that, as of 2012, only 0.6% of Americans commuted by bicycle:
This increase in the number of bicycle commuters exceeded the percentage increase of all other travel modes during that period, but the overall share of workers who commute by bicycle remains low. In 1980, 0.5 percent of workers commuted by bicycle. This rate dropped to 0.4 percent in 1990, where it remained in 2000. By 2008–2012, the share of bicycle commuters reached 0.6 percent (emphasis added).