Triumph 6T Thunderbird

1954 was a big year at Triumph Motorcycles, in general. Finally the archaic rigid frame and troublesome sprung rear hub were ditched for a proper swing arm frame. Not a moment too soon, either. AMC, Royal Enfield & the BSA Gold Star were already running swing arms and Norton was about to introduce the swingarm-equipped Norton Dominator with the legendary Featherbed Frame. Triumph had some catching up to do. This would prove to be a year of change for the Triumph motorcycle line.

1954 was also the year Triumph introduced the hot new Triumph Tiger T110. The new top 650 model was the high-performance variant and it's development trickled down to the other models. The Tiger T110 featured higher compression, wilder cams and a bigger carb, and still ran a magneto, offering much more performance. The 1954 Triumph Thunderbird, once the flagship of the Triumph Motorcycle line & the fastest bike they produced, was now marketed as the detuned, commuter (or 'plodder') version, although the two bikes continued to be styled almost identically.

The 1954 Triumph Thunderbird was extensively restyled, as were all Triumphs, with a new look that somehow retained its historical relevance with Triumphs past. They looked great! A new color, Shell Blue Sheen was striking on the new bikes.

Performance also got a big shot in the arm for the 1954 Triumph Thunderbird. The entire Triumph 650 line got a stiffened crankshaft with increased shaft diameters, larger conrods and a new crankcase with larger 1-1/8" MS11 ball race on the timing side. Revisions to the primary cases were made to accommodate the new Lucas RM14 3-lead alternator.

NEW SWINGARM FRAME
The new swingarm frame shortened the wheelbase by 1-inch, to 55-3/4". It was a single front downtube with the swing arm pivot mounted to the saddle tube and nothing else. The vertical saddle tube flexed like a torsion bar, allowing the swing arm to move sideways. This would end up being a real problem on the higher performance Triumph Tiger T110 & much later on the first year 1959 Triumph Bonneville. Because of this tendency to weave, the frame gained the nickname "Whip Iron".

GEARING
The engine package was also made more compact by pushing the gearbox closer to the crankcase and shortening the primary cases. The primary chain was down to 70 links. Out back, the lower half of the chain guard was deleted. The gearbox cases were modified along with a new adjusting (rotating the gearbox in its mounts as the only means of adjusting the primary chain tension) and clamping system. The gear indicator pointer was also dropped.

Front fork springs were lengthened to 20 inches and rear shocks were 3-position slim-bodied Girlings with 110lb springs early in the year, with 125lb springs mid-year on. A centerstand appeared for the first time ever on a Triumph motorcycle.

NEW BODYWORK
The new frame called for many new parts, including a new oil tank (claimed to be 6 pt, but was actually only 5) which also housed the battery tray, air cleaner & tool box. As always, the 6T Thunderbird came with well-valanced fenders, a new stepped two-place seat & headlight nacelle.