Rule 12 for the ignorati:

Rule #12 // The correct number of bikes to own is n+1.
While the minimum number of bikes one should own is three, the correct number is n+1, where n is the number of bikes currently owned. This equation may also be re-written as s-1, where s is the number of bikes owned that would result in separation from your partner.

Image shared by @AnnaMeares, on Twitter. Pity, she has just 3 bikes!