Pre-unit Triumph twin that suffers from excessive vibration when thrashed but generally competent motor when used mildly. Swinging arm upgrade in the mid-fifties, proper full width brake in ’57 and the Bathtub rear end in the sixties, none of which did anything to help the dire handling at speed. A lot of engines ended up in Norton or even BSA frames! Generally, the newer the bike the better it behaves.