Rumi - Junior Gentleman
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Rumi D2-492-31-01
Photo ou archives : F-M. Dumas

Capacity : 125
Model : Junior Gentleman
Production : 1955 - 1959
Category : (R) Street Bike


125 Junior Gentleman -1955

Best in class

In 1955, Rumi- who concentrated on twostroke twin power units - made a racing machine designed for the regulations of the Italian Formula Junior Gentleman, which limited the carburetor choke to 18mm (0. 7 inches).

A Real Street Racer

Lean and lively, the Rumi Junior Gentleman became the favorite machine in this new category. Successor to the legendary Gobbetto, this client-competition machine was "domesticated" with street equipment so that it could compete in the classic Italian races like the Milan-Taranto. It also raced with distinction in events like the Bol d'Or in France and the 24 Hours of Montjuich in Spain. The basic power unit was the famous horizontal twin that powered the marque's scooters, but fitted with twin carburetors and either a straight through muffler or a megaphone exhaust.

Rolling Test Bench

Throughout its racing career, the Junior Gentleman also served as a test, on which Rumi tried liquid cooling, rotary valves, electronic ignition and expansion chambers. Powerful, reliable and a pleasure to ride, this excellent spottster was superior to most 250s of its day. It had Earles front forks and benefitted from the highly-efficient hub brakes of its predecessor. The high performance flywheel magneto and the crankcases had been redesigned in the interest of better cooling. The Junior Gentleman remained in production until 1959.


Engine: 125cc ( 42x45mm) air-cooled twin cylinder

Power Rating: 11 hp @ 7800 rpm

Valves: two-stroke

Fuel System: two carburetors with shared float chamber

Transmission: 5-speed, chain final drive

Suspension: Earles forks (front); swing arm with twin spring/dampers (rear)

Brakes: twin drum/single leading shoe (front); quad-show drum (rear)

Wheels: 2.50x19 wire (front & rear)

Weight: 165 lb

Maximum Speed: 70 mph with mufflers/81 mph with megaphones


Also built in 175cc capacity, the Rumi junior Gentleman is one of the most collectable Italian competition bikes of the 1950s.

Motorcycle encyclopedia Moto Passion, realised by François-Marie Dumas, include almost 2000 photos presented with an exhaustive history of the motorcycles exhibited.

This unique collection has been realised with the participation of many specialists. With many thanks in particular to Yves Campion, Michael Dregni, Didier Ganneau, Jean Goyard, Helmut Krackowizer, Michel Montange, Christian Rey, Bernard Salvat, Mick Woollett, etc

One can order here

  • Original cards on paper (in french)
  • High resolution scans or original documents presented and signed with my name.

Please contact me at for conditions and copyright.

© Tous droits réservés
François-Marie Dumas

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