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1959 Triumph Thunderbird

1959 Triumph Thunderbird

ABOVE: This 1959 Triumph Thunderbird has more than a healthy amount of patina. In fact, if it wasn’t all in one piece, it might be a basket case. Sorry I couldn’t do better on a photo, but it was the only one I could find that I had the rights to use. If you have a ’59 T-Bird, please send us some pictures.

T-BIRD – BY THE NUMBERS
For the 1959 model year, all continued the model designation of “6T” and had an engine prefix of 6T as well. Engine and Frame Numbers ran from 020581 to 029362, a span of 8,781 units, built from October 9, 1958 to February 9, 1959, which was a production run of only 4 months exactly.

ENGINE UPGRADES
The prior 3-piece crankshaft was replaced by a stronger, lighter one-piece forged steel crank with a bolt-on central flywheel. The vacuum SU carburetor was replaced with an Amal Monobloc Type 376/210. A Lucas RM15 alternator was installed to increase output over the RM14 unit it replaced.

GEARBOX IMPROVEMENTS
From engine #023941, the gearshift camplate was induction-hardened to reduce wear. From engine #024029, the clutch sprocket was also induction-hardened. An oil level indicator was added to the inner gearbox cover.

1959 TRIUMPH THUNDERBIRD CYCLE PARTS
The front brake cam lever was modified to improve its braking abilities, and those thus-modified were marked with an “X” on the lever. US models now came with a safety strap on the seat. This was the alt year for the single downtube frame (aptly nicknamed “Whip Iron” for it’s tendency to flex so much as to be dangerous. The last Triumph 650 with a Whip Iron frame was a 1959 Triumph Thunderbird, Engine & Frame #029362.

1959 TRIUMPH THUNDERBIRD PAINT COMBOS
The standard paint colors for the 1959 Triumph Thunderbird were as follows: The petrol (fuel) tank was Charcoal Gray. The tank badge had white lettering on a black background. The mudguards (fenders) were also Charcoal Gray with a Black center strip, lined in White. The front fork covers/headlight nacelle were solid Charcoal Gray. And the oil tank and battery box were Gloss Black, along with all the other painted parts on the bike. The one exception is the front hub, which was painted an Eggshell Black.


1959 Triumph Thunderbird SPECIFICATIONS

Engine type

Displacement

Bore & Stroke

Compression

Carburetor

Ignition

Engine output

Primary drive

Primary sprockets

Clutch

Gearbox

Ratios, overall:

1st, bottom

2nd

3rd

4th, top

Final drive

Final drive sprockets

Frame Type

Suspension, front

Suspension, rear

Brake, front

Brake, rear

Tire, front

Tire, rear

Wheelbase

Seat Height

Ground Clearance

Fuel capacity

Dry weight

Air-cooled OHV vertical twin, non-unit

649cc / 40.0 ci

71mm X 82mm / 2.79″ X 3.23″

8.5:1 (US & export); 7.0:1 (UK)

1-Amal Monobloc

Lucas magneto

34 bhp @ 6500 rpm

1/2″ X .335″ X 5/16″ chain, 70 links

24T X 43T

Multi-plate, wet

4-speed constant mesh, right foot shift

11.9:1

8.25:1

5.81:1

4.88

5/8″ X .400″ X 3/8″ chain, 101 links

18T X 46T

Brazed lug, rigid

Telescopic fork, hydraulic damping

Swing arm, 2 Girling dampers

8″ SLS drum

7″ SLS drum

3.25″ X 19″

3.50″ X 19″

55.75″ / 141 cm

31″ / 77.5 cm

5″ / 12.7 cm

3 Imp gal (US); 4 Imp gal (UK & export)

395 lbs / 179 kg