Two big things stand out here for me: 1) white people remain somewhat over-represented; but 2) bicycling appears to be trending toward racial parity. As of 2009, roughly 21 percent of all bike trips in the US were made by people of color, and it looks as though US cyclists may soon look pretty darn similar to the nation as a whole.
He also compares income and finds that "contrary to popular convention, the biggest share of bicyclists isn't yuppies, it's low income people. In fact, the lowest-earning quarter of Americans make nearly one-third of all bike trips."
I have a bike and no car. And cars are the primary reason we are so indebted to foreign autocracies sitting on sand and oil. But Americans, as usual, don't want to give up their cars (often more than one in a family), and don't want to pay any gas taxes. Then they complain about wars in the Middle East. Driver, heal thyself.