so i am looking at a number on stirrup bar of a black country dressage saddle ,says BS 6635 and searching the web,find it means “standard tree” .i have a vague idea what a hoop tree is and understand that a standard tree is like an inverted V ( or at least i think so ) but what else is a standard tree ? is it the same as a “classic” tree ? it is flat or is it curved and what type of horse will it fit ?or what other specifications does it have ?
thanks all !