sentences:  It was smaller and weighed five pounds less than the £70 Tiger 90, and proved very successful.The 5T Speed Twin (some say based on the engine design of Turner's Riley Nine car) became the standard by which other twins were judged, and its descendants continued in production until the 1980s.The original 27 bhp parallel-twin was capable of exceeding 90 mph (145 km/h) and weighed 361 lb (166 kg).