Mine is a trailing arm, as are all my builds. The shock is not directly mounted to the arm and the ride height bell crank is horizontally below parallel with the frame. Angled down ... will also reduce wheel lead when compressing, which may or may not come into play halfway 'round a sweeper as the COG shifts. The smoothness of the ride is dependent on the damping of the shock. The way mine is set up it introduces a rising rate. The shock angle also contributes its own rising rate so they compliment each other while still soaking up small and large bumps. * edit, plus my roll and instant centers are further forward due to the design. ... and you thought this was gonna be simple Pic's taken from my current build thread. If I want more travel from the chair suspension I only need to change one thing.