Statement? I could imagine a neo-nazi who thinks cycling could help build a stronger, tougher people to better conquer the world. Or a Maoist on a Flying Pigeon who supports Communist China and decries the economic changes there. Or a Republican, Democrat, or Libertarian. Or a nonpartisan, patriotic American, who wants to cut back on petrodollars that will inevitably find their way to terrorists.
I think that riding a bike is too ambiguous to be a political statement, even though it may well reflect a political position and have significant social impacts. All it means for sure is that you are riding a bike.
Paul