Just guessing, from memory, but it looks a circa ’65 Triumph Bonneville.
These were not “the best” motorcycles, at least for reliability and vibration. For around town or local cruising, they were fun. It took some thinking to switch between English and Japanese bikes, the British bikes had a left foot rear brake and right foot shifter pedal.
Drum brakes, spoked wheels, Lucas electrical… I preferred the Sportster in that era. Soon, thereafter, a lot of choices started showing up, in two stroke and four stroke, but Honda did the deal with the Goldwing series.