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
Ok, i am not a H-A owner but i surely agree on it's great technical quality. IMHO, it's a perfect hitch by desing. Now i see 2 discussions here. First, how doe's the H-A eliminate sway and second, the "apparent" or "virtual" point of pivot between the TV and TT. I made 2 hand drawing to explain my comprehension of the system.
I think we all agree that sway is the result of the TT pivoting aroud a point locate in the center of the axles forcing the tongue to the left and right (laterally) pushing the back of the TV sideways up to a point where control of the rig can be lost. Lots of factors are involved here like wheelbase, overhang of the hitch ball from the rear axle, tongue weight etc.
We also agree that sway only occur at speed over 45 to 50 mph (+/-)
So, at this speed, TT and TV are in straight line 99% of the time. This is where the HA desing is unique, it locks completely (from the TT point of vue) the TT and TV just like riding on a railroad. It has the same effect as welding a 6" I beam from the back of the TT to the front of the TV. Rotation is impossible if induce by the TT (sway). The HA trapezoïd 4 bars linkage combined with the 2 struts bars are locking the TV and TT. On highways or country roads, the TV and TT are always almost straight so with the HA, there is no apparent pivot point of rotation close, after or forward the TV axles. Lateral forces will be on the entire TV frame (from the HA to the receiver to the TV frame).
The apparent pivot point between the TT and TV appeers when and only when the TV induce a rotation and will occur only at low or very low speed in close manoevring (city driving, parking, backing-up) except on a panic and rapid lane change on highways.
Hand drawing of the HA without the strut bars : HA drawing 1
Hand drawing with the strut bars and what they do : HA drawing 2
This is also why with the HA, the TV has always the control of the TT. With this hitch, a jacknife situation is totally impossible in panic stop whatever the speed.
Now, here is my comment of a non HA owners ;)
Technically, it is a perfect hitch but it's to bad that in their advertising video, the let the impression that it's also a perfect "idiot proof" hitch. Don't take me wrong, HA owners are NOT idiots ! But when they claimed that you can load your TT with heavy stuff in the back not having any taughts about the tongue weight etc. After all, the HA will take care of any unstable rig due to an uninformed driver who know's nothing of the physics of towing (wide majority on the road).
P.S. The cherry over the cake was the ... lawyer (in the video)!
Best regards to all.
I think we all agree that sway is the result of the TT pivoting aroud a point locate in the center of the axles forcing the tongue to the left and right (laterally) pushing the back of the TV sideways up to a point where control of the rig can be lost. Lots of factors are involved here like wheelbase, overhang of the hitch ball from the rear axle, tongue weight etc.
We also agree that sway only occur at speed over 45 to 50 mph (+/-)
So, at this speed, TT and TV are in straight line 99% of the time. This is where the HA desing is unique, it locks completely (from the TT point of vue) the TT and TV just like riding on a railroad. It has the same effect as welding a 6" I beam from the back of the TT to the front of the TV. Rotation is impossible if induce by the TT (sway). The HA trapezoïd 4 bars linkage combined with the 2 struts bars are locking the TV and TT. On highways or country roads, the TV and TT are always almost straight so with the HA, there is no apparent pivot point of rotation close, after or forward the TV axles. Lateral forces will be on the entire TV frame (from the HA to the receiver to the TV frame).
The apparent pivot point between the TT and TV appeers when and only when the TV induce a rotation and will occur only at low or very low speed in close manoevring (city driving, parking, backing-up) except on a panic and rapid lane change on highways.
Hand drawing of the HA without the strut bars : HA drawing 1
Hand drawing with the strut bars and what they do : HA drawing 2
This is also why with the HA, the TV has always the control of the TT. With this hitch, a jacknife situation is totally impossible in panic stop whatever the speed.
Now, here is my comment of a non HA owners ;)
Technically, it is a perfect hitch but it's to bad that in their advertising video, the let the impression that it's also a perfect "idiot proof" hitch. Don't take me wrong, HA owners are NOT idiots ! But when they claimed that you can load your TT with heavy stuff in the back not having any taughts about the tongue weight etc. After all, the HA will take care of any unstable rig due to an uninformed driver who know's nothing of the physics of towing (wide majority on the road).
P.S. The cherry over the cake was the ... lawyer (in the video)!
Best regards to all.
