Low numbers of people in “your” cycling organizations and advocacy groups. From the comments on “Why I’m not a ‘cyclist’ anymore,” a story about moving from a bicycle subculture (United States) to bicycle culture (Copenhagen):

In Amsterdam, 700,000(?) people cycle, only 4,000 are member of the Fietsersbond (cyclist’s union). We always explain this comparing it to the non-existing vacuum-cleaners union. Everybody owns and uses a vacuum cleaner, no-one feels the urge to unite themselves around this.

People riding their bicycles in Copenhagen, Denmark.