Ron Gratz
full time RVer
Senior Member
Joined: 12/27/2003
View Profile
|
Hensley Arrow Pivot Point Location versus ProPride Pivot Point Location
Quote:Pivot point actually moved even further forward, due to stinger being slightly shorter than Hensley
The lengths of the HA hitch bar and the 3P hitch bar need to be confirmed. Based just on the photos, it appears the 3P bar might be longer.
It’s not just the length of the hitch bar which is of concern. The length of interest is the distance from the face of the hitch receiver to the ball coupler when the TV and TT are connected. The “projection” distance is measured from the ball.
Related Post #1, Related Post #2, Related Post #3, Related Post #4, Related Post #5,
Related Post #6, Related Post #7, Related Post #8, Related Post #9, Related Post #10,
Related Post #11, Related Post #12,
* This post was
last
edited 09/07/08 09:22am by Ron Gratz *
View edit history
|
willald
NC
Senior Member
Joined: 07/15/2002
View Profile
|
Ron Gratz wrote:Mr. Hensley did not claim that the yolk offered any stability improvement over the strut assembly described in his previous patents. Rather, the yolk was introduced as a means to allow for trailer tongue “shortening” when used with a surge brake.
Right, I don't think anyone ever claimed the yolk design improved stability directly. Not sure I quite follow the tongue 'shortening' you mention here, but I do know that Sean specifically went into why he did away with the struts and designed the yolk system. Mostly, it was to do away with the risk of frame brackets slipping with those U bolts/shear bolts that are used with the Hensley.
Quote:The 3P adjustable bar is multi-piece with bolted construction and numerous welds. The HA bar is a single piece with no welds for the straight bar, and relatively few welds for the drop/raise bars.
Indeed. Same could be said in comparing the hitch shank used on conventional WD hitches, with the HA bar.
In either case, though, I would think as long as the welding is done right, there would never be a problem.
Quote:An adjustable hitch bar with bolted construction has not previously been used with a 4-bar linkage hitch.
Right, but such has been used on conventional hitches, for a very, very, long time.
Quote:The 3P hitch bar appears to weigh more than the HA bar (this needs to be confirmed).
Possibly, but the 3P altogether still weighs somewhat less than the HA hitch IIRC. Sooo, even if what you say is true about the ProPride bar weighing more, the weight advantage still goes with the 3P, overall.
Ron Gratz wrote:The lengths of the HA hitch bar and the 3P hitch bar need to be confirmed. Based just on the photos, it appears the 3P bar might be longer.
It’s not just the length of the hitch bar which is of concern. The length of interest is the distance from the face of the hitch receiver to the ball coupler when the TV and TT are connected. The “projection” distance is measured from the ball.
..Interesting point. Perhaps we need to do like we did back in the old HA technical thread I started some time ago, and take some specific measurements of the 3P, to answer this question..
If the distance is longer like you suggest, that would be completely inconsistent with what I was told about how they intended to design the 3P. That being the case, I have a hard time buying that the distance is longer, without seeing some specific measurements.
Will
* This post was
edited 09/02/08 02:29pm by willald *
|
Ron Gratz
full time RVer
Senior Member
Joined: 12/27/2003
View Profile
|
Hensley Arrow WD Bar Attachment versus ProPride 3P WD Bar Attachment
Quote:Better design that holds the WD bars in place (does not use grease zerks like Hensley uses, that are prone to wear out with time and allow bars to fall out when unhitched)
It would help to see some details of the 3P design.
The HA system is described on Page 18 of the online HA manual.
The vertical end of the WD bar has a “spring bar groove” into which a “spring bar retainer pin” fits. Some bars can shear off the retainer pin if they are swung too far to the side. Other WD bars with a different shape at the ends of the groove do not seem to cause this problem. The HA manual gives instructions on how to avoid damage to the retainer pins.
Related Post #1
Related Post #2
Related Post #3
9/3/08 Summary
The HA uses retainer pins to hold the WD bars in place when they are completely unloaded. In normal use, the load on a bar holds the bar in the hitch head and the retainer pin does not come into play.
Some HA owners have found retainer pins to be broken off or worn off. A retainer pin is part of a replaceable Zerk fitting.
No information has yet been provided about how the 3P bars are held in place when completely unloaded.
* This post was
last
edited 09/03/08 10:28pm by Ron Gratz *
View edit history
|
Ron Gratz
full time RVer
Senior Member
Joined: 12/27/2003
View Profile
|
Hensley Arrow WD Jacks versus ProPride 3P WD Jacks
Quote:Jacks used for WD bars place weight on top of A frame instead of outside, reducing risk of the frame brackets bending with age
The HA frame brackets and jack installation are shown on Pages 14 & 16 of the online HA manual.
The bottom end of an installed 3P jack can be seen in the fourth photo on this web page. The Lockhart photo seems to show that the center of the 3P jack is outside of the frame rather than bearing directly on top of the A-frame. Also, the link which pulls up on the WD bar attaches to the U-shaped “hook” which is welded to the outside of the jack on its outboard side.
In the HA system, the upward force on the WD bar is aligned with the vertical center of the jack. It seems to me that there might be more of an eccentric loading of the 3P’s brackets. Again, some properly oriented photos and some measurements would help in clarifying any “differences”.
|
Ron Gratz
full time RVer
Senior Member
Joined: 12/27/2003
View Profile
|
Hensley Arrow Construction versus ProPride 3P Construction
Quote:Link pieces, bearings, etc. are built even more solid (thicker, heavier) than ones used on Hensley
I understand that the 3P's link pieces are thicker. But, I'm not sure about the "bearings, etc." being heavier than the HA counterparts.
Since the 3P's hitch bar appears to be heavier and the 3P's yoke assembly appears to be heavier than the HA's struts and the 3P's link pieces, bearings, etc. are claimed to be heavier, I'm wondering how the 3P can be lighter overall.
It would be interesting to see a comparison of 3P and HA weights.
Related Post #1
Related Post #2
* This post was
last
edited 09/05/08 07:43pm by Ron Gratz *
View edit history
|
|
|
Ron Gratz
full time RVer
Senior Member
Joined: 12/27/2003
View Profile
|
Availability of Hitch Bar with Ball Coupler
Quote: Availability of adapter piece I mentioned above, that will allow shops to move your trailer if need be
I know an adapter piece for the 3P has been discussed – but is it really available?
Some HA owners already are using custom-made adapters. An example can be seen here.
Related Post #1
Related Post #2
Related Post #3
Related Post #4
9/3/08 Summary
Some HA owners have found a need for being able to move their TT using a ball rather than having to insert a hitch bar into a hitch receiver. Some HA owners satisfy this need by using a custom-made adapter such as shown here. Others might prefer a commercially-made adapter if reasonably priced.
No details have yet been provided for the design, cost, or date of availability for the purported 3P adapter.
* This post was
last
edited 09/03/08 10:29pm by Ron Gratz *
View edit history
|
willald
NC
Senior Member
Joined: 07/15/2002
View Profile
|
Ron Gratz wrote:The HA system is described on Page 18 of the online HA manual.
The vertical end of the WD bar has a “spring bar groove” into which a “spring bar retainer pin” fits. Some bars can shear off the retainer pin if they are swung too far to the side. Other WD bars with a different shape at the ends of the groove do not seem to cause this problem. The HA manual gives instructions on how to avoid damage to the retainer pins.
See, Ron, this is the kind of (false) statements that can result, when one draws conclusions strictly from 'arm chair quarterbacking' and theory, instead of actual real world experience with something.
Those that have actually owned a Hensle, know that those retainer pins can and will eventually shear off from wear, no matter how well you follow instructions or not. Doesn't matter how far the bars are swung or not swung. Don't believe it? I can send you one or two sheared off pins sitting on my workbench right now, that I've collected over the years of REAL WORLD experience with a Hensley. 
Like I said, those pins shearing off and causing the WD bars to fall out (when unhitched), are indeed one of the bad things that happens every so often with a Hensley. Supposedly, this is something that was corrected with the Propride hitch. I agree, that it would be very helpful to see the ProPride's design, that addresses this issue. Perhaps someone that owns a 3P could chime in and address this?
Will
|
willald
NC
Senior Member
Joined: 07/15/2002
View Profile
|
Ron Gratz wrote:Availability of Hitch Bar with Ball Coupler
Quote: Availability of adapter piece I mentioned above, that will allow shops to move your trailer if need be
I know an adapter piece for the 3P has been discussed – but is it really available?
Some HA owners already are using custom-made adapters. An example can be seen here.
Don't believe ProPride's adapter is available yet, no. But, it will be soon from what I understand.
Yes, I'm aware of the custom made adapters. However, I think an adapter made specfically for this purpose by the manfuacturer and with their full support, is a MUCH better solution than a custom-made contraption that you have to put a screwdriver blade through to make it work. Wouldn't you agree, Ron?
Will
|
willald
NC
Senior Member
Joined: 07/15/2002
View Profile
|
Ron Gratz wrote:Hensley Arrow Construction versus ProPride 3P Construction
Quote:Link pieces, bearings, etc. are built even more solid (thicker, heavier) than ones used on Hensley
I understand that the 3P's link pieces are thicker. But, I'm not sure about the "bearings, etc." being heavier than the HA counterparts.
Since the 3P's hitch bar appears to be heavier and the 3P's yolk assembly appears to be heavier than the HA's struts and the 3P's link pieces, bearings, etc. are claimed to be heavier, I'm wondering how the 3P can be lighter overall.
It would be interesting to see a comparison of 3P and HA weights.
Hmmm, good point. Indeed, it would be interesting to compare such. I'll see if I can dig up some specific numbers on that.
In looking at the two units, I think you can see where the ProPride makes up for a lot of the weight difference, just in that the upper part of the hitch is nowhere near as big on the 3P.
Perhaps one of the many new 3P owners out there can chime in, with any weight numbers they may know from having the hitch shipped to them?
Will
|
Ron Gratz
full time RVer
Senior Member
Joined: 12/27/2003
View Profile
|
willald wrote:Ron Gratz wrote:The 3P adjustable bar is multi-piece with bolted construction and numerous welds. The HA bar is a single piece with no welds for the straight bar, and relatively few welds for the drop/raise bars.
Indeed. Same could be said in comparing the hitch shank used on conventional WD hitches, with the HA bar.
In either case, though, I would think as long as the welding is done right, there would never be a problem.
Ron Gratz wrote:An adjustable hitch bar with bolted construction has not previously been used with a 4-bar linkage hitch.
Right, but such has been used on conventional hitches, for a very, very, long time.
A 4-bar linkage hitch imposes a very large yaw-axis torque on the hitch bar. That is the basis on which it works.
A conventional hitch imposes a much smaller yaw-axis torque on the hitch bar. That's why a conventional hitch is not as effective at controlling sway.
So you really can't equate the loads and stresses and fatigue which are imposed on a conventional hitch with the loads and stresses and fatigue which are imposed on a 4-bar linkage hitch.
The conventional hitch mainly transmits pitch-axis torques. The 4-bar linkage hitch must transmit both pitch-axis torques and yaw-axis torques at the same time.
For that reason, I think the 3P's adjustable hitch bar is more susceptible to overstressing and fatigue damage than is an adjustable hitch bar for a conventional hitch. But, until there are a lot more 3P user miles accumulated, we really won't know.
Ron
|
|
|
|
