Tensioner-free drivetrain assembly, bicycle, and method of manufacturing same

A drivetrain assembly comprising:

• a bottom bracket shell having a front through-hole defining a front axis;
• at least one dropout having a rear through-hole defining a rear axis;
• at least one chainstay member directly or indirectly attached to the at least one dropout and the bottom bracket shell;
• a front sprocket rotatably coupled to the front through-hole;
• a rear sprocket rotatably coupled to the rear through-hole;
• and
• a chain or belt extending around and in contact with the front and rear sprockets, the chain or belt including a bottom section extending from a first contact point between the chain or belt and the front sprocket to a second contact point between the chain or belt and the rear sprocket,
• wherein the at least one chainstay member fixes the at least one dropout relative to the bottom bracket shell, such that a chainstay length, which is the shortest distance from the front axis to the rear axis, is non-variable, and such that the chain or belt has a predetermined tension defined by a midpoint of the bottom section being vertically displaceable only by a maximum vertical extent within a predetermined range upon application of a predetermined load at the midpoint of the bottom section.