Description
A definitive history of Triumphs two most popular models in the 1940s and 1950s In depth information on the Thunderbird not previously available. Year-on-year development history on both models. Year-by-year engine and frame numbering enabling correct identification. Colour schemes used throughout the model life. Photographs and colour prints showing each model in detail. Competition success and achievements for both models.

Synopsis
The aim of this book is to give a complete technical development history of the Speedtwin and Thunderbird. As a reference this book will be a valuable asset for anyone aiming to restore a Speedtwin or a Thunderbird to the correct specification.
Used as guide it will enable a would be purchaser or owner to establish the exact year of manufacture and identify the model type.