Having purchased this book 5 years ago, it has been a fantastic tool that I have used to good effect on 2 purpose-built road racing motorcycles. It is well written and easy to understand, with examples that work through relatively simple formulae and have concise conclusions at the end of these examples, making the importance of, and potential gains from develoments easy to see. It is of benefit to engineers, designers, racers and riders, and motorcycle enthusiasts generally. If you want to really start understanding motorcycles, if you want to go faster, buy and apply this book to your bike and your riding, before spending more money on engine tuning, countless tyres and track time. Worth every penny!