Tribsa

A Tribsa comprises a Triumph parallel twin engine installed in BSA motorcycle frame.

The BSA frame was a duplex-cradle design which was considered stiffer and stronger than the Triumph's single downtube item.

A batch of nine TriBSAs were planned by the BSA-Triumph for the 1966 ISDT using 348 cc, 490 cc and 'special capacity' 504 cc 'short' Triumph twin engines in a frame using geometry from the BSA Victor scrambler, Victor front forks and wheel together with a Triumph QD rear wheel in a Triumph swinging arm[4] A light-alloy Gold Star type fuel tank and a steel oil tank were fitted together with three ignition coils, one as a spare.

[5][6] The 490 cc prototype was finished and tested in Wales with the remaining batch utilising the other engine sizes scheduled to follow.

In today's vintage off-road events, Tribsas may be seen competing in motocross, enduro, and trials.