Robin Dunn decided he wanted to bike across the country when he was 12. “We read a book about a teacher who takes a bunch of fifth graders on a cross country bike ride and I wanted to do that,” he said.

It wasn’t the only thing he ever wanted to do. As a young man he traveled around the globe visiting the great religious sites; he received commendations for his scholarship and athleticism becoming an academic all-American for the Colorado College swim team, and he found time to get into all the trouble a college kid gets into. He stashed the idea of a cross country bike trip somewhere in the back of his mind, and when he was asked what he was going to do when he graduated, it surfaced.

“We’re going to bike across the country,” said the 27-year-old. “It was an idea like we’re going to go to the moon but Ari was like, ‘Yeah, let’s do it.’” So the Colorado College alumni set off to prepare. Dunn and his companion Ari Stiller-Shulman, were thinking about all the logistical questions: what the route would be, what kind of bikes to ride and where to stay. The Colorado natives undertook these preparations while finishing their college degrees.

Their preparations weren’t physical, however. They were both athletes in good physical shape, but they didn’t train physically for the trip. In fact, Stiller-Shulman whose story is at least as interesting as Dunn’s, had only been biking a few times in his whole life and never more than 12 miles in a trip. On the trip they would need to bike somewhere between 70 to 80 miles a day to stay on schedule.

Generally, bikers endeavoring to cross the ...