Hensley Arrow: How does it REALLY work?

TnAnFLA wrote:
Now comes the hard part. How do you explain the "bump" that can happen if the TT brakes don't engage soon enough , or at all, when slowing down. It would seem that scenario would add even more compression to the hitch assembly. My only guess is that it's velocity dependant (i.e., it only happens when the TT slows down really quickly relative to the TT) and that the mass of the TT at those velocities is enough to cause the rear link to translate to one side or the other. And the beauty of it all is that since the head translates as opposed to the TT swinging, the net force vector on the TT/TV assembly is still pretty much straight ahead so even in a panic stop you don't end up swerving or swaying into your buddy in the adjacent lane.

Andy

I've experienced the bump only once, and I don't care to experience it again. If you're braking, AND in a turn beyond the "collapse point" of the side link on the inside of the turn, AND the trailer brakes aren't restraining the trailer (it would be difficult in a deep turn due to the statics of the forces) the trailer will actually move forward until the side links lock. The forces on the hitch (the part supplied by GM in my case) are not trivial. Other posts have commented on the problems with the GM hitch in this regard.

When it happened to me it was a slight bump, but enough for me to know what was going on. I immediately realized I had the boost turned off on my controller, so I quickly rectified that situation. With my 1/2 T p/u I used to run B3, but now I'm using B1 and that's fine. No boost at all is a problem...

The amount of kinetic energy difference between the TT and the TV in this situation cannot be great - as the relative speeds are similar. The additional travel might be 6" or so, but the decel forces involved in quickly stopping a moving 8,000 TT cannot be trivial. Hence the bump.

Ed