Donny Petersen 
Donny’S Unauthorized Technical Guide to Harley-Davidson, 1936 to Present 
Volume I: the Twin Cam

Volume I: The Twin Cam is the updated first volume of Petersen’s long-awaited Donny’s Unauthorized Technical Guide to Harley-Davidson, 1936 to Present series. This twelve-volume series by the dean of motorcycle technology examines the theory, design, and practical aspects of all things Harley-Davidson.

Circa l’autore

The Twin Cam: 1999 to Present has won the 2012 International Book Awards.

DONNY PETERSEN is the founder and former operator (1974 to 2009) of Heavy Duty Cycles in Toronto, Canada. His monthly column, Techline, has appeared in in American Iron Magazine since 1992. Instructed privately by Harley-Davidson engineers, he has taught mechanics, designed tech-school curricula, and authored student-licensing examinations. A Toronto resident, Petersen is a 43-year rider of Harley-Davidsons.