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
Tim,
I completely agree with your methodology. For the Excursion, I am guessing that the TV axle to ball distance would be closer to 60" for the conventional hitch and 72" for the HA. Using these numbers with your other dimensions, the conventional hitch would have a reactionary moment of 250 ft-lb and the HA's would be 87.1 ft-lb.
While my guesstimates do not give such a large reduction percentage as do yours, I believe these figures easily explain why the HA is able to control the lateral stability as well as it does.
Lateral instability is a threshold exceedence phenomenon. The forces and moments on the TV must exceed a certain level in order for the system to go from being stable to being unstable. By its ability to reduce the magnitude of the TT-imposed forces and moments, the HA raises the level at which the instability will occur.
Contrary to what the Hensley advertising materials would have one believe, the HA does its job without creating a rigid connection between TT and TV and without causing the TT/TV combination to, in the words of the HA marketers, '"think" and "act" like a straight unit, a straight truck if you will.'
Ron
I completely agree with your methodology. For the Excursion, I am guessing that the TV axle to ball distance would be closer to 60" for the conventional hitch and 72" for the HA. Using these numbers with your other dimensions, the conventional hitch would have a reactionary moment of 250 ft-lb and the HA's would be 87.1 ft-lb.
While my guesstimates do not give such a large reduction percentage as do yours, I believe these figures easily explain why the HA is able to control the lateral stability as well as it does.
Lateral instability is a threshold exceedence phenomenon. The forces and moments on the TV must exceed a certain level in order for the system to go from being stable to being unstable. By its ability to reduce the magnitude of the TT-imposed forces and moments, the HA raises the level at which the instability will occur.
Contrary to what the Hensley advertising materials would have one believe, the HA does its job without creating a rigid connection between TT and TV and without causing the TT/TV combination to, in the words of the HA marketers, '"think" and "act" like a straight unit, a straight truck if you will.'
Ron
