Hensley Arrow: How does it REALLY work?
There have been several discussions on this hitch that have become somewhat 'controversial'. I am NOT trying to stir this controversy/bashing back up. Instead, I'd like to see a good, intelligent di...
Forum Discussion
Will,
Thanks for reopening your thread. This is even more fun than fishing.
Will and Don,
If the "can't swing because it can't move toward the pivot point" theory is correct, then no pendulum can swing because gravity would not allow the mass to move upward. Galileo Galilei could not have invented the pendulum and we would have had no pendulum clocks.
Worse yet, no one would need a Hensley Arrow because no TT could swing. Even with a conventional hitch, a TT must be able to move forward (against the force of wind and tire drag) if it is to swing. If the force prevents the conventionally coupled TT from moving forward, then it cannot swing and no sway control is needed.
The problem with the theory is that the drag forces on a TT, whether it is coupled with a conventional hitch, a HA, or a PR do not prevent it from moving forward when the TT is subjected to lateral forces. If the force were that large, you would not be able to tow it -- even with an Excursion. Similarly, gravity does not prevent a pendulum from moving upward when it is pushed to the side.
Of course the ball coupler on an HA moves forward when the TT swings. That is because the ball coupler and TT are swinging as though they are pivoting about the virtual pivot point. The ball coupler and TT also move forward when the TT is coupled to a PR. That is because the coupler and TT are pivoting about the actual pivot point which is up close to the TV's rear axle.
Neither a HA nor a PR have any way of "locking" to prevent the TT from swinging. Well, actually the PR does; but you would not want to tow a TT with it in that mode.
Ron
Thanks for reopening your thread. This is even more fun than fishing.
Will and Don,
If the "can't swing because it can't move toward the pivot point" theory is correct, then no pendulum can swing because gravity would not allow the mass to move upward. Galileo Galilei could not have invented the pendulum and we would have had no pendulum clocks.
Worse yet, no one would need a Hensley Arrow because no TT could swing. Even with a conventional hitch, a TT must be able to move forward (against the force of wind and tire drag) if it is to swing. If the force prevents the conventionally coupled TT from moving forward, then it cannot swing and no sway control is needed.
The problem with the theory is that the drag forces on a TT, whether it is coupled with a conventional hitch, a HA, or a PR do not prevent it from moving forward when the TT is subjected to lateral forces. If the force were that large, you would not be able to tow it -- even with an Excursion. Similarly, gravity does not prevent a pendulum from moving upward when it is pushed to the side.
Of course the ball coupler on an HA moves forward when the TT swings. That is because the ball coupler and TT are swinging as though they are pivoting about the virtual pivot point. The ball coupler and TT also move forward when the TT is coupled to a PR. That is because the coupler and TT are pivoting about the actual pivot point which is up close to the TV's rear axle.
Neither a HA nor a PR have any way of "locking" to prevent the TT from swinging. Well, actually the PR does; but you would not want to tow a TT with it in that mode.
Ron
