Bernt Spiegel's The Upper Half of the Motorcycle was a best-selling motorcycling book in its original German with multiple editions and printings to its credit. Now translated into English, its provocative message is available to a wider audience.

Spiegel's metaphor considers the rider and the motorcycle as a single unit, the rider being the upper half. Taking a multidisciplinary approach, the author draws on anthropology, psychology, biology, physics, and other disciplines to analyze the theory and function of the man-machine unit.

Motorcycle riding is seen as a junction where people have created machines for personal transport and then become so adept at using them that the machine becomes like an extension of the rider themself. The ultimate goal for riders is the integration of the man-machine interface and subsequent skill development to the point of virtuosity. Spiegel considers the various aspects of motorcycle riding that must be understood, practiced, and mastered before virtuosity can be attained.

Many anecdotes, supplementary material, and in-depth treatment of specialized topics is contained in sidebars and footnotes. Numerous diagrams and photographs illustrate the book's principles allowing the reader to consider and develop their riding skill set.