BSA 1953ca A7 TRIBSA 750cc 2cyl OHV 3406



BSA 1953ca A7 “TRIBSA” 750 cc vertical twin with Triumph engine frame # BA7S 5378 engine # 6T 46984

In 1937 Triumph had launched its Speed Twin which became a great success. BSA couldn’t stay behind so the company started to develop a vertical twin in the years before the war. This model was to make its appearance in 1940 but by that time BSA got very much involved in the war effort and the launch of new models was postponed. In September 1946 the new twin became available as the A7; it was to be the first of a long line of powerful and reliable parallel twins that carried the Piled Arms trademark. Plunger rear suspension and swingarms were to replace the rigid end in years to come. In the 1960s and 70s quite a few enthusiasts started to combine the best of two worlds; the Triumph engine had twin camshafts which supposedly facilitated tuning for a greater power output and was faster than the BSA twin. However, the duplex BSA frame was stiffer and stronger than the single downtube Triumph frame. Consequently the custom-built “Tribsa” was born, often assembled with various proprietary parts that were considered superior to the factory-fitted items.
This scrambler-look Tribsa has been overhauled and the basically 1954-type Triumph engine received new pistons, valves, and valve guides. The cubic capacity was brought to 750 cc and the engine was made suitable for unleaded fuel. Aluminium heads have been fitted and the electrics were converted to 12 volts. The engine is held by Converta mounting brackets and the fuel tank is a Lita product. The sparks come from a rewound Lucas competition magneto.
The front forks fitted are Marzocchi with Ceriani with two-leading shoes brakes. Hagon shocks are used for the rear suspension and the headlamp is held by a pair of John Tickle brackets. Front and rear mudguards are aluminium and the exhaust are high-level. She comes with 180 km Smiths speedo and, as the cherry on the cake, a Norton gearbox. Which would make this attractive machine a TRIBSANO…
All together this is a fast and reliable road legal motorcycle and in contemporary vintage events Tribsas compete and often win in motocross, enduro, and trials. But she’ll be real fun on the road too!