Tribsa was a modified cafe racer motorcycle of the 1960s-1970s.
The intention was to combine the best elements of each to give a superior bike to either. The usual practice was to take the Triumph parallel twin engine and use it to replace the engine on a B series BSA motorcycle which were generally single cylinder. The Triumph engine gave good performance and reliability and could be tuned easily for greater power. The Tribsa was an alternative to the Triton which was a Triumph engine in a Norton Featherbed frame.