A terminology issue arises. Triumph does not sell the Americas nor the speedmasters with solo seats. They do sell the speedmastiffs with a combo saddle/pillion. Maybe that is the confusion. Forget what they call that particular combo. My Corbin pillion will work with the stock saddle. Not that I would want to use the oem saddle. And I am using the oem saddle bolt with the Corbin saddlery.
