Setting Free the Bears — John Irving

Siggy and Hannes were disenchanted students and fellow conspirators. With their horny haunches astride a 700cc Royal Enfield motorcycle they roamed the Austrian countryside, living off the land and the landowners .. . joined on their journey by Gallen, a long-limbed lovely hitchhiker ... zeroing in on the Vienna Zoo and Siggy's life-long objective: setting free the bears.