Originally Posted by
mrfish
The angle of the stem makes no difference to the load which the captain's seatpost 'sees' where it is clamped into the frame, whether it clamps at the top, bottom or somewhere in between. If you think of the stoker stem and bars as a system, the forces put into the system by the stoker's hands must always to be balanced by the forces which the frame exerts on the captain's post.
Components don't fail due to *loads*.
They fail due to *stresses* (load/area).
Stresses will change based on where you choose to load a component.