check my wdh numbers please

The forces on both sides are not equal because as the cam travels up the spring bar towards the hitch, the spring has to bend farther upward creating much more force to push the trailer back behind you. If the bar is level, the initial energy required to move the cam out of the V is much greater. If the bar is angled downward, the cam only has to move in a straight line to move out of the V. This initial tension is what keeps the trailer straight.

Yes, the bars are bent in an arc but they can be closer to parallel with the frame. This resits allowing the cam to travel up them and creates more tension to push the trailer back straight behind you.