The Triumph Thunderbird Sport 900, produced from 1996 to 2004, represents a blend of classic British motorcycle heritage and modern performance. As Britain's oldest motorcycle manufacturer, Triumph has engineered this model to offer a compelling riding experience, characterized by its powerful liquid-cooled, 12-valve, inline 3-cylinder engine delivering approximately 97 HP and 75 lb-ft of torque. Praised for its strong torque, comfortable riding position, and classic styling, the Thunderbird Sport 900 is well-suited for touring and spirited riding. Its robust frame construction and dual front disc brakes contribute to its capable handling and reliable performance. This comprehensive workshop service repair manual in English provides detailed guidance for maintaining and repairing the Triumph Thunderbird Sport 900. It covers complete engine and transmission disassembly, repair, and overhaul, alongside in-depth troubleshooting and diagnostics for the electrical, fuel, ignition, cooling, exhaust, chassis, suspension, and brake systems. With hundreds of photos and illustrations, numbered instructions, substeps, notes, cautions, and warnings, this manual is an invaluable resource for both do-it-yourself enthusiasts and experienced mechanics. It facilitates regular servicing, component repairs, and general upkeep, ensuring the vehicle remains in optimal working condition and avoiding costly dealership repairs.