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
Andy,
Thanks for posting the video link. A problem with a thread which has 445 posts is that almost no one has read all of them.
Tim Luxon has posted a good discussion of the HA "test model". I have commented as well. I agree with Tim's assessment and I'll try to summarize my previous comments.
The HA test model is very misleading because it uses a full-size HA on a reduced-scale "tow vehicle" and "trailer". This causes the HA's virtual pivot point to be very close to (perhaps ahead of) the "TV's" rear axle instead of being two feet or more behind the axle which would be the case in real life. This completely changes the interaction between "TT" and "TV" and is part of the deception of the model.
Also, in real life, the TV would be moving and its tires would be rolling. As I have stated previously in this thread, a rolling tire develops no lateral resistance unless it has a yaw angle. In the HA "test model" the guy doing the pushing would have to overcome the static resistance of the wheels in order to make it move sideways. This is another part of the deception of the model.
Perhaps we are not looking at the save video. I see no evidence that the wheels on the "TT" portion or the rear wheels on the "TV" portion are free to swivel. The only caster wheel I see is the single one on the front of the "TV".
Well, I guess you could saw through a TT's A-frame just rearward of the strut attachments. Then you could have the struts under compression (you'd have to add a tie between the cut ends of the A-frame) and the A-frame/coupler attached to the HA. The HA's rear unit (with struts and A-frame attached) would move just as freely as the video shows.
Ron
Thanks for posting the video link. A problem with a thread which has 445 posts is that almost no one has read all of them.
Tim Luxon has posted a good discussion of the HA "test model". I have commented as well. I agree with Tim's assessment and I'll try to summarize my previous comments.
The HA test model is very misleading because it uses a full-size HA on a reduced-scale "tow vehicle" and "trailer". This causes the HA's virtual pivot point to be very close to (perhaps ahead of) the "TV's" rear axle instead of being two feet or more behind the axle which would be the case in real life. This completely changes the interaction between "TT" and "TV" and is part of the deception of the model.
Also, in real life, the TV would be moving and its tires would be rolling. As I have stated previously in this thread, a rolling tire develops no lateral resistance unless it has a yaw angle. In the HA "test model" the guy doing the pushing would have to overcome the static resistance of the wheels in order to make it move sideways. This is another part of the deception of the model.
It appears to me that the frame supporting the "TT" end of the assembly is in fact on casters, free to rotate 360 degrees (you can see them rotate more clearly toward the end of the clip) so your contention that the resistance of the TT tires to lateral forces as being the primary resistance to sway isn't the case.
Perhaps we are not looking at the save video. I see no evidence that the wheels on the "TT" portion or the rear wheels on the "TV" portion are free to swivel. The only caster wheel I see is the single one on the front of the "TV".
I think the problem with Tim's video is that the strut bars are not hooked up, so it's not a full test of the hitch's resistance to a lateral force.
Well, I guess you could saw through a TT's A-frame just rearward of the strut attachments. Then you could have the struts under compression (you'd have to add a tie between the cut ends of the A-frame) and the A-frame/coupler attached to the HA. The HA's rear unit (with struts and A-frame attached) would move just as freely as the video shows.
Ron
