The Triumph Thunderbird was introduced in 1949 as part of the UK’s export drive, largely to cahs in on the burgeoning market for British bikes in the American market. 

The 6T Thunderbird used a variant of the earlier Speed Twin's parallel twin engine, bored out from 500cc to 650cc to give the added horsepower American customers demanded. The concept of enlarging the Speed Twin, the Thunderbird name and its 'paper dart' logo were thought up by managing director Edward Turner on one of his regular trips to Triumph's operations in the USA. 

The 6T Thunderbird was launched publicly at Montlhéry near Paris, where three standard-production bikes were ridden around a circuit by a team of riders who between them averaged a speed of 92 mph over a distance of 500 miles. That was 73 years ago – a pretty impressive achievement!

What we have here, though, is something truly special. A 1950 Thunderbird T6 that has never, ever been restored. It’s a very special thing with a story all of its own.

The Triumph was supplied new to a Mr W in Stockport, Cheshire, who kept it until his death in 1982. It then passed on to his son and subsequently his grandson, but wasn’t used for over 35 years as neither of them were bikers.

The vendor acquired it from the family in 2014 and brought it back to Norfolk, where he found it had no compression. After a full service and fresh fuel, it fired straight up and still does to this day. He’s replaced the exhaust pipes out of necessity, but otherwise the bike is exactly as found and has never been restored. It really does need to stay that way…

Included with it are all the old V5 documents covering its ownership with the family, along with a selection of historic invoices which are a snapshot of time in terms of its ownership. It also has a selection of old tax discs, as well as some other fascinating artefacts such as a voting slip from the 1973 Labour Party Conference….

Let’s get one thing clear – this is not a concours condition bike. Far from it, in fact, but that’s the core to its appeal. It’s tired and run down at first appearance, as it wears a 72-year-old patina that in 2022 should not ever be removed from it. It’s a 1950 bike that has never been restored or painted. The bodywork is tired, the forks have marks, the frame has scuffs, the wheels are original. And that must never change, for this bike is as much as snapshot of social history as it is a classic showpiece. 

The vendor took it to a national bike show soon after he got it running again and he reports that it attracted more attention than any of the restored models on show. We’re not surprised.

In 1955, after numerous trips to Devon from Yorkshire, with a D/Adult sidecar fitted and the family aboard, the old  engine went bang, so its owner at the time bought a T110 engine which had just been released (iron head version). This has been in the bike ever since and is more powerful than the 6T engine.

Amazingly, the 650cc twin fires up on the first kick – aside from service items, the owner has never replaced anything so it’s an incredible achievement that it still works as Triumph intended. It runs well, and at a bike event on a private track the vendor reports that it still achieved a recorded 90mph on the clock. The Thunderbird was, after all, one of the seminal sports bikes. 

Also of note is the sprung hub – the Triumph has no rear suspension so has springs inside the rear hub. In operational terms, not a bad idea – but one that was killed off early on for the safety of mechanics working on them, as the sprung tension inside the hub could cause injury!

This is a truly wonderful bike. Arguably unique, as it’s unlikely there are any other unrestored 72-year-old Thunderbirds out there with the same patina, in the same condition, and with the pedigree this one has. It’s a remarkable, unusual machine and one that deserves to be preserved exactly as it is.