Triumph Thunderbird restoration guide
THE SPECIALIST
Combining many years working in the motorcycle trade with a keen interest in classic machines, Ian Mosscrop branched out on his own to launch Thunderbird Spares in 2007. Not just Thunderbirds, but his activities include supplying parts for all classic Triumphs as well as BSAs and Nortons. The business also offers rebuilding and tuning services. Many thanks to Ian for his assistance with this guide.
■ Thunderbird Spares: 01772 691377;
www.thunderbirdspares.com
MODEL HISTORY
The Speed Twin had already shown the world there was a viable alternative engine to the near-ubiquitous single. In 1949, Triumph raised the bar again with the launch of the 650cc Thunderbird. The evocative name, inspired by an American motel, proved apt when three launch versions running on low-octane ‘Pool’ petrol, still managed 500 miles at 90+ mph average speeds circulating the Montlhéry track, near Paris.
As Triumph's flagship model, the Thunderbird neatly eclipsed BSA’s A10 650, launched around the same time, with both companies desperate for bigger shares in the expanding USA market. Designer Edward Turner had come up with Art Deco-influenced styling changes and an increased capacity Speed Twin engine to produce a master-stroke in production engineering. While the 650 layout was the basis for more sporting Triumphs long into the future, the Thunderbird proved a popular option for the many riders who wanted fuss-free, long-legged performance.
The years of production saw the model evolve, changes usually in step with various other Triumph twins. There were improvements to frames and suspension. The most dramatic change was the adoption of the contentious bathtub bodywork in 1960, although this was arguably closer to Thunderbird ethos than some of its sibling models. In 1963, the preunit Thunderbird was displaced with unitary engine/ gearbox, which gave the model a few more years of life.
PRICING
Fifties Thunderbirds in smart order sell for around £7500, so a project with most parts present could justify a £3k price ticket. Everything may well fit together, even work together, but be careful that it all once left Meriden together as one bike if a factory-spec restoration is the aim.
IN CONCLUSION
Early rigid or Sprung Hub Thunderbirds are now of pensionable age and may well take some finding, especially unmolested. Swinging arm bikes are far more plentiful. Whatever the choice of model, commonality of parts with the rest of the Triumph range means everything that may be required is out there somewhere, but the factory introduced many updates so beware of detail incompatibilities. If riding is more important, the later crankshaft was a much stronger design and the one to look for when a bike to cover some miles is required.
The finished job provides the owner with a thoroughly practical classic. The investment market has helped dictate values among the pantheon of 650cc Triumph models, the Thunderbird becoming a lesser light. Yet the qualities of easy starting and delivery of ample performance that made the original version so desirable are equally valid today, especially with the improved ride and comfort of the swinging arm versions. A practical classic for the modern day and secured for perhaps half the price of a Bonneville.
The manufacture gained unwelcome notoriety with Thunderbird-riding Marlon Brando’s appearance in ‘The Wild One’ but for Triumph’s export sales figures, the Thunderbird certainly pressed the button for International Rescue.