The Spirit Flyer Series is a series of children's novels written by John Bibee. It is an allegorical adventure series for young readers and recounts the exploits, mishaps, and triumphs of John and Susan Kramar and their friends, who find themselves thrown into a cosmic battle between good and evil in their otherwise ordinary town. The books revolve around the fictional town of Centerville, and the magical Spirit Flyer bicycles that are found there. There are eight books in the series.