Tag Archives: Doninno Rumi

Rumi Motorcycles | 125cc two-stroke twin broke new ground

Junior Racer

With Phil Aynsley


An anchor hardly seems to be an appropriate part of a motorcycle company’s emblem, but for Rumi it made sense. Originally formed in the early 1900s to produce cast metal products such as propellers, during WWII it turned to armaments manufacture including miniature submarines, periscopes and torpedoes.

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Rumi Junior Racer – Rumi started off producing cast metal products, but later expanded

After the war Donnino Rumi (the founder’s son and a noted artist and sculptor) diversified the company’s products to include dough mixers, textile machinery and, from 1950, an individualistic range of 125cc twin cylinder 2-stoke motorcycles and scooters, all powered by the same basic engine designed by Pietro Vassena.

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Rumi manufactured a range of successful 125cc twin cylinder 2-stoke motorcycles

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This engine (in competition form) was the first in a motorcycle to employ alloy barrels with a chrome plated bore and expansion chamber exhausts – at least in a rather basic form.

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The Junior featured alloy barrels with a chrome plated bore and expansion chamber exhausts in a rudimentary form
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Rumi Junior Racer

The Gobetto in ‘Rumi | From submarines to motorcycles’ (link) was the factory’s top of the line race bike and was produced from 1951 to 1955 when it was replaced by the Junior. The Junior continued the use of chrome plated, alloy barrels and was fitted with two 18mm Dell’Orto carburettors and 10.5:1 compression pistons as standard.

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A race kit was also available for the Rumi Junior

Top speed was over 112km/h, however with the factory race kit, including larger carburettors, 11.5:1 pistons and racing exhaust pipes, this was raised to around 130km/h.

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Rumi Junior Racer
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Rumi Junior Racer front fork ‘shocks’

Earles front forks were standard but telescopic units were an option. The Sturcher rear shocks were air-assisted and featured adjustable dampening.

The Junior was the bike to beat in sport production racing in Italy and France during the late ‘50s. In 1959 it was in turn superseded by the Junior Gentleman.

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Rumi Junior Racer

Apart from having the motor rebuilt this bike is in original, unrestored condition.

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Rumi Junior Racer
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Rumi Junior Racer

Source: MCNews.com.au