Triumph Bonneville TR6 650 Cylinder Jug 1963 – 1972 2.815 Date June 7, 2016Posted by claynes This listing is for a used Triumph cylinder. The cooling fins are all intact. The bore measures 2.815 inch as it sits. This is a “9” hole cylinder. They came on 1966 thru 1972, and can be retro fitted to earlier models. Comes as shown in pictures.