The Triumph 350cc and 500cc unit-construction twins were called the 'C' Series, and were made between 1957 and 1974. The range started with the 350cc 'Twenty-one' - a sedate touring bike with full enclosure in the form of the famous Triumph 'Bathtub' - went through such famous names as the Speed Twin, Tiger 100 and Trophy, and ended with the rip-roaring Daytona and the off-road Adventurer. This book deals with the whole range, giving the history of all the models, and also describes the restoration of a 1969 Trophy T100C.