Motorcycle Classics – September-October 2019

22 MOTORCYCLE CLASSICS September/October 2019

Modern Triumph Motorcycles: 1937-Today, was available only as the

TR6A road-going model and the TR6B “scrambler” machine.

Triumph’s big news for 1959 was the introduction of the

sporting twin-carb T120 Bonneville. The TR6 Trophy would

then after be known as the single-carb machine, but apart from

the number of carburetors, the two models were similar in

specification.

By 1963, the year Triumph moved

from separate transmission/engine

construction for its 650cc machines

to full unit construction, the TR6

was offered as the TR6SS (siamese,

low-level exhaust), TR6SR (sepa-

rate low-level headers and mufflers)

and the TR6SC (with separate high-

rise headers and mufflers). All TR6

motorcycles used the new-for-1963 single-downtube frame,

which offered increased rigidity compared to the duplex-frame

of 1960 to 1962.

The engine cylinder head increased from eight mounting

studs to nine to address an issue with combustion chambers

which occasionally cracked. The rocker boxes sprouted fins

around their bases and the inspection caps shrank in size. A

2-row primary chain was included, the magneto dropped, and

coil and points ignition took on the job of making sparks.

The last year for the TR6SR designation was 1966 — the year

of Tom’s machine. After that, the “S” was dropped and in the

years following it was the TR6, TR6R and TR6C.

For 1966, the TR6SR had a 3-1/2-gallon slimline gas tank with

new “eyebrow” Triumph badges and a parcel rack screwed to

the tank top. Instead of a 6-volt electric system, the voltage had

been increased to 12 and was regu-

lated by Zener diode with a finned

heat sink mounted to the front fork,

immediately below the headlight.

In 1966, the TR6SR was available in

Pacific Blue and Alaskan White and

the twin saddle featured a gray top

and white ribbing. The fenders were

painted white, accented by a blue

strip lined with a gold pinstripe. The single-carb TR6 continued

until 1973, when it was dropped from the Triumph range.

Going back together

Tom’s 1966 TR6SR was not a stock motorcycle when he had

it. He remembers it with a taller handlebar and custom paint

job, and he wasn’t fussy about it going back together to origi-

nal specification — he just wanted to ride it. That’s when his

“Tom wasn’t concerned about

the bike being original, so we

had quite a bit of freedom.”