In 2005 Doug Waterman, a retired teacher who lives in Davis, rode his bike solo from Santa Monica to Chicago on Route 66. He also was 66 at the time. A decade later, he has written a book about the trip—“It Only Hurts When I Sit Down: A Bicycle Adventure on Historic Route 66”—and he appears on Davisville today to talk about what he saw along the way. He is joined by his wife Donna, who wrote nightly emails for their friends and family. His recollections include tales of good deeds and usually friendly folks, ghost towns, storms he barely outran, odd moments, and a truck tire he saw explode on the road.