Book excerpt: Popular motorcycle journalist and author Mark Zimmerman brings a comfortable, conversational tone to his easy-to-understand explanations of how motorcycles work and how to maintain them and fix them when they don't. This practical tutorial covers all brands and styles of bikes, making it a perfect companion to the owner's service manual whether you need to use the step-by-step instructions for basic maintenance techniques to wrench on your bike yourself or just want to learn enough to become an informed customer at your local motorcycle service department. This book includes more than 500 color photos and a thorough index to make it an especially user-friendly reference for home motorcycle mechanics of all skill levels.