1921 225cc Triumph Junior
Triumph’s first motorcycle with a two-stroke engine was unveiled at the 1913 Olympia Show. Soon nicknamed the ‘Baby Triumph’ the 35mph Junior was aimed at utility and novice riders, keenly priced at less than £45.
The basic three-port 225cc (64 x 70mm) engine runs on a 12:1 petrol-oil mix. A decompressor valve operated by a handlebar lever is used for starting, when the rider paddles off, and stopping. To avoid noise and oil spatter, it releases gases into a passage connected to the exhaust. A lever on the left handlebar selects high and low speeds and final drive is by belt. A good seller, the Junior was enlarged to 249cc for 1923. Early two strokes were mechanically noisy and it was said that this Baby was never without its rattle.
