1964 Triumph T20SM Mountain Cub

Old and Slow, by Choice

By Dain Gingerelli
Updated on October 16, 2023
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by Dain Gingerelli

Triumph’s T20 Tiger Cub, introduced to the motorcycling community in 1954, earned its marketing moniker and still steals racer’s hearts today.

1964 Triumph T20SM Mountain Cub

Engine: 199cc air-cooled, OHV 4-stroke single, 63mm x 64mm bore and stroke, 7:1 compression ratio, 10hp @ 6,000rpm
Carburetion: Single Del’Orto 22mm
Transmission: 4-speed, right foot shift
Electrics: Lucas AC/DC
Frame/wheelbase: Single downtube/49in (1,245mm)
Suspension: Tube front fork, Worx Shocks rear shock absorbers
Tires: 3.00 x 19in front and rear
Brakes: 5.25in (133mm) drums front and rear
Weight (dry): 182lb (83kg)


The nifty little bike, powered by a single-cylinder 199cc 4-stroke engine, remarkably resembled the company’s alpha male Tiger T100, a bike that was the pride of the pack because it was the fastest of all Triumph models at the time. Fittingly, Triumph’s marketing team capitalized on the physical likeness shared by the T20 and T100, proclaiming in subsequent Tiger Cub T20 ads the handsome little bike was “A Real Triumph in Miniature!” Specifically, you might say, it was a proportionally scaled down version of a Tiger T100.

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