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Old 04-06-2007, 06:07 AM   #21
bsmeaton
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Ozz - also, if you you have the 1116 Pin Box, the replacement 5th airborne is 1-1/2" shorter in length.
 
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Old 04-06-2007, 07:58 AM   #22
Cat320
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Like the guys above, I moved my hitch as low as it will go and the Montana is still a bit nose high. Also, my 5th Abn is a bit shorter, too...just short enough that I can't lower the tail gate all the way down when hooked up. Or, as I discovered last trip as I was all hooked up and ready to go, I can't raise the tail gate.
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Old 04-06-2007, 05:06 PM   #23
Dave e Victoria
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I would like some one to explain the kinematics of the 5th airborne hitch. Looking at their website tells me nothing. They have a few platitudes and refernce to unnamed competitors. I thoroughly understand both the Mor ryde and the air ride both of which I have owned and both of which directly address chucking motion. But there is nothing on the website description of 5th airborne that even suggests what mechanism works in the fore aft direction. I'm still convinced that Mor ryde has the most elegant and best performing anti chucking device on the market.

I know some of you are reporting good results with the 5th airborne vs a bare trailer hitch but I just wonder why. The brochure is without fact -- just so much marketing BS. Please tell me how it actually works. Where does the energy go?
Dave
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Old 04-06-2007, 05:16 PM   #24
exav8tr
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Thank you for asking that Dave. I was considering a 5th Airborne but I really know nothing about them. We have a Husky 16k EZ Roller hitch and a standard Lippert pin box. We are going to leave as is and drive the Alcan south and then make a further decision when we get to Tacoma or Seattle, or wherever the CW is. Sure would like to be able to understand all this talk. Perhaps by the time I get to Washington, I will know what you guys are talking about....Counting the days.......
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Old 04-07-2007, 04:19 AM   #25
Ozz
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I would imagine in the shock.
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Old 04-07-2007, 05:16 AM   #26
Dave e Victoria
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Ozz,
The shock has to be caused to move. What is the geometry of the hitch that allows the hitch to flex when excited by a fore/aft motion. In the air ride design the pivot point is misaligned with the hitch point so fore aft motion tends to be translated into up down motion where the shock and airbag take over.. The mor Ryde puts the elastic member directly in the foreaft axis so no translation has to take place. So what is happening with the 5th airborne mechanism?
Dave
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Old 04-07-2007, 05:33 AM   #27
MikeM
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Quote:
quote:Originally posted by Dave e Victoria

Ozz,
The shock has to be caused to move. What is the geometry of the hitch that allows the hitch to flex when excited by a fore/aft motion. In the air ride design the pivot point is misaligned with the hitch point so fore aft motion tends to be translated into up down motion where the shock and airbag take over.. The mor Ryde puts the elastic member directly in the foreaft axis so no translation has to take place. So what is happening with the 5th airborne mechanism?
Dave
Dave - I believe that the location of the pivot pin on the pin box is what creates the translation of motion to allow for dampening of chucking. If you look closely at the design, you'll see that the pivot pin is forward of the hitch pin. I'm not a mechanical engineer, but when a chucking motion occurs, it appears to create a rotational motion around the pivot pin and the chucking is then absorbed by the shock and air bag combination.
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Old 04-07-2007, 05:55 AM   #28
Dave e Victoria
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Mike,
The pivot point must be above the hitch point for the translation to occur. The website drawing makes it look like the forward motion of the trailer pushes the inside of the hitchso it rolls around the TV hitch pivot. If this is the case, it should be pretty much identical to the trail air. The system is first order damped spring so if motion stays within the range of the shock and spring (ie: does not bottom out) the system should be able to reduce chucking ampltudes by about 6 db and chucking energy about 3db.
Thanks for the help. I was hoping I would see some revolutionary device. Instead it is just more of the same although this one certainly looks better than the trail air.
Dave
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Old 04-07-2007, 06:14 AM   #29
SKOOBDO
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Since this thread is discussing pin boxes and hitches, I thought instead of starting a new thread, I will ask you guys what "Pin Box" would you recommend to reduce the shocking effects of the standard pin I have when hooked up to a standard Reese Hitch? I would like to replace my Pin Box, but have no clue on really which one to buy. I'm not expecting a miracle, but would like something to reduce the "impact" on waffle board roads. I was planning on getting one at the dealer when I got my bedsaver installed last year, but wasn't for sure which one to have installed. I'll await your responses...I appreciate any input. thanks!
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Old 04-07-2007, 06:19 AM   #30
bsmeaton
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Dave - I would have to agree with you that the Mor-Ryde is a straight forward design for chucking, offering 3" travel fore and aft.

However, both the Fifth Airborne and the Trailair pin boxes offer limited dampening of the fore and aft movement, relying on the pivot action of the hitch. I wouldn't have understood until a guy pulled up next to me at a light with a Trailair, and I could watch his hitch in action. The truck stopped, and the forward momentum of the trailer resulted in the air bag expanding as the truck hitch tilted forward, countered by the trailer recoiling backward, compressing the air bag as the truck hitch tilted backward. It was actually a neat display of the action and then I understood.

The Fifth Airborne works the same, except the pin box pivot is in the front rather than in the rear like the Trailair.

I guess this is my best explanation:


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Old 04-07-2007, 06:36 AM   #31
Dave e Victoria
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You are exactly right. The up down motion on a trail air can be very diconcerting to watch. And Having owned both, I much prefer the Mor ryde. Having said that, anyone contemplating one of these devices should make sure they are loaded properly first. Nothing will help a truck or trailer that has its main suspensions overloaded. In addition, heavier pin weights will always ride better.
Dave
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Old 04-09-2007, 10:38 AM   #32
Heli 190
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I have the Trail Air pin box and found it to be pretty rough on our first leg of the trip last summer. They want you to keep the pressure adjusted using the arrows on the shock. I talked to the factory tech and he said to set the pressure where I got the best ride. The higher the better.I finally figured out my biggest problem was having to much pressure in my bags on the truck. After decreasing the pressure on the truck bags and increasing the pressure on the pin box bags to 100psi, I ended up with a pretty decent ride. I still get a little up and down motion, but it is livable. Trail Air is supposed to be working on the up down problem with a differant lower jaw on the pin box.
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Old 04-09-2007, 10:48 AM   #33
Ozz
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Man, it's always something. You would think these guys would have all that worked out when they put a product on the market and we spend our hard earned money on it.............
Thanks for the info, good luck with it.
Ozz
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Old 04-09-2007, 03:15 PM   #34
Dave e Victoria
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Ozz,
It's not too hard to understand the difficulty in designing and testing these products. What we have is a collection of second order systems that each have a tendency to become non-linear or even saturated. The systems all have similar frequency responses so have a tendency to interfere with each other. This wouldn't even be so bad but the systems are not contained or mounted to anything particularily ridgid. That is, truck beds bend, loads shift and road surfaces defy prediction.

As a result of the above, the designs are rather imperical in nature and are a result of trials and errors until something is found that seems to work. Then, just like in Dilbert, marketing goes to work trying to recover some investment.

This is why I am a bit cynical about these products and also why I look for the most simple solutions. Simple solutions tend to keep you out of unexpected behavior.

Early in my career in engineering I remember one of the guys telling about the first "optimal" flight control system. In an early flight on one of the x-planes, it encountered a supersonic skid where it responded with a supersonic spin whereupon the pilot ejected. Unfortunately, we RV'rs don't wear parachutes. Fortunately, we rarely need them. But, bear in mind, an aircraft is far, far easier to model than the supension on a random RV connected to a random TV.
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Old 04-09-2007, 05:20 PM   #35
chub
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I have the Trail Air pinbox and wouldn't have a camper without it. This is the second camper we have had with the Trail Air and it works great. I really notice it on concrete roads.
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Old 04-09-2007, 07:11 PM   #36
Dave e Victoria
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Jeff,
I think that is exactly the point. You, your rig, the way you drive, and the roads you drive on are a good match for trail air. I had similar experience and I also had the air ride shocks. But others, as reported, have not had a happy experience. There are so many variables it is next to impossible to make a scheme that will satisfy everyone. More over, the more complicated we make it by adding more variables the more likely we are to not know what is actually going on.

This is the reason I have not jumped at adding air rides to my new truck. It seems to be towing just fine with the Mor Ryde hitch. I'd hate to screw that up. But, my truck rides low and I would like to correct that. One advantage of air rides, if you don't like it they can be deflated and everything is back to stock.
Dave
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Old 04-10-2007, 05:17 AM   #37
Clyde n Deb
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Ozz...............if you're intereted in a MorRyde, I might suggest calling them direct and haggle a bit on price. Have you established if there is a true dealer near you or not? Do you have a friend in the biz that could order one for you? Aren't you known as "Ozz's RV Repair and Accessories"? Deals have been known to work out.......
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Old 04-10-2007, 05:57 AM   #38
Ozz
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I like the way you think, Clyde. I will do that

Dave, I have the Two Firestone air bags, as Steve R. has, I believe. I love mine, and as you pointed out, you can adjust them where you need the leveling.
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Old 04-10-2007, 06:50 AM   #39
Clyde n Deb
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Ozz: I sent you a PM. Clyde
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