Why don't 5th wheel mfgrs place more heavy items in rear?

[Alley_Fox]

OK, maybe a naive question but why don't 5th wheel manufacturers place some of the heavier items in the rear to help relieve the heavy pin weights? I'm thinking about things like gensets, water tanks and propane. Pin weight recommendations usually say 10%-25% of total trailer weight so why not try to help relieve some of that? What's the tradeoff?

[Jim-Linda]

Alley Fox wrote:
Jim-Linda- I have a 32" Visio LCD TV. Does that mean I am good to go?? 😉



Just kidding, of course.......

Of course, we have a 32" Samsung In our HH.

Jim

[Vulcaneer]

Water-Bug wrote:

REWahoo wrote:

motorcycle jack wrote:
The placement of the items inside has very little to do with the pin weight. It is where the balance point versus the axle placement that effects it most. If you have a problem with understanding that, let me give you an example. Lets say the given 5th wheel has a total weight of 10K and the pin weight is 2K (20% of total weight). Now add 1K to the rear of the unit. Does that mean the pin weight is now 1K? Since you added it behind the axle (which is not the balance point). No. The total weight is 11K (10 + 1) and the pin weight is now 20% x 11K or 2200 lbs. Sorry, just the nature of the design.

An engineer will be along shortly to point out the inaccuracies in the above post. 🙂

He rides a bike. Cut him a little slack. 🙂

How do you know that he does not jack up a bike?:)

I think it is a combination of axle locations, and also loading positions for basement storage, tank locations, kitchen weight, closets, and also how much acceptable range is in the pin weight spec. vs the gvwr.

I ride a bike too. And sometime jack one up. And jack it down. Wait... is that even possible? To jack something down?:h

[WyoTraveler]

When I was kid, long time ago, we had a teetertotter also called a seesaw. We would change the fulcrum point depending on weight of each person. Basically the pin weight will change based on where the wheels are located in respect to the hitch & the rear of the RV and where the weight is placed. i.e. the further back toward the rear beyond the wheels the more it will lighten the pin weight. This why the loads are balaced to give us the proper hitch weight. Obviously adding weight to the extreme front or rear will have a greater effect. How the axle handles the load is another matter.

[n7bsn]

Water-Bug wrote:

REWahoo wrote:

motorcycle jack wrote:
The placement of the items inside has very little to do with the pin weight. It is where the balance point versus the axle placement that effects it most. If you have a problem with understanding that, let me give you an example. Lets say the given 5th wheel has a total weight of 10K and the pin weight is 2K (20% of total weight). Now add 1K to the rear of the unit. Does that mean the pin weight is now 1K? Since you added it behind the axle (which is not the balance point). No. The total weight is 11K (10 + 1) and the pin weight is now 20% x 11K or 2200 lbs. Sorry, just the nature of the design.

An engineer will be along shortly to point out the inaccuracies in the above post. 🙂

He rides a bike. Cut him a little slack. 🙂

OK (and yes, he is wrong, as Archimedes could have proven)

[Lantley]

DSteiner51 wrote:

jaycocamprs wrote:

Lantley wrote:
Wow are we confused. Why does a locomotive pull the train and not push it? The weight holds the train on the tracks.

The locomotive pulls the train because the cars are not strong enough in compression. They would crush the rear cars.

Trains have absolutely nothing to do with pulling 5th wheels. The locomotive carries no weight from anything it pulls and is planted on rails.

Only that the weight is in the front leading the train.
But I agree it is not the best analogy because the effect of downward forces are not as critical

[Me_Again]

Alley Fox wrote:
OK, maybe a naive question but why don't 5th wheel manufacturers place some of the heavier items in the rear to help relieve the heavy pin weights? I'm thinking about things like gensets, water tanks and propane. Pin weight recommendations usually say 10%-25% of total trailer weight so why not try to help relieve some of that? What's the tradeoff?

So you have an AF model that is noted for high pin weight and most likely a 2500 that is noted for low CC. Blaming the trailer for the issue is looking at the wrong component! High tare weight of diesel 4x4 pickups and low GVWR and RGAWR ratings of 250/2500 trucks are the real problem.

Chris

[Cummins12V98]

Anything of any weight is on and mostly forward of my axles. I have well over 4,500# pin weight and my 5er tows great.

Too light of pin weight and it will be a bad ride.

To answer a question, who would want a Generator in the living area? Noise and space it would take up is why they don't. Same with Propane bottles they would take up space.

[DSteiner51]

The higher the percentage of weight up to 50% the better. 10% travel trailers often use anti sway devices, 20% 5th wheels/goosenecks don't. Neither do 50% semi trucks. Ideally 50% would be the ticket but most people don't own trucks big enough for 50%. 20 - 25% is a compromise that works quite well.

Going back to the OP, the farther aft of the pivot point, (axles) the weight is the better pendulum it becomes. A good reason to put the junk department between the truck and trailer axles.

[DSteiner51]

jaycocamprs wrote:

Lantley wrote:
Wow are we confused. Why does a locomotive pull the train and not push it? The weight holds the train on the tracks.

The locomotive pulls the train because the cars are not strong enough in compression. They would crush the rear cars.

Trains have absolutely nothing to do with pulling 5th wheels. The locomotive carries no weight from anything it pulls and is planted on rails.

[DSteiner51]

goducks10 wrote:

Jim-Linda wrote:
If one uses a sufficient TV, pin weight doesn't matter.

Jim

Ding Ding Ding and we have a winner:)

Ding Ding Ding, we have two losers!!

[cutty72]

jaycocamprs wrote:

Lantley wrote:
Wow are we confused. Why does a locomotive pull the train and not push it? The weight holds the train on the tracks.

The locomotive pulls the train because the cars are not strong enough in compression. They would crush the rear cars.

BNSF is commonly using 2 pull engines and 1 push engine on trains in my area.

[Alley_Fox]

Jim-Linda- I have a 32" Visio LCD TV. Does that mean I am good to go?? 😉



Just kidding, of course.......

[goducks10]

Jim-Linda wrote:
If one uses a sufficient TV, pin weight doesn't matter.

Jim

Ding Ding Ding and we have a winner:)

[RCMAN46]

Pin weight does matter. The more the better the trailer will tow. That is why 5th wheel trailers handle much better than a pull trailer and if the pin weight is in the 25% area they almost never have sway or any other handling problems provided the TV can handle the pin weight. The only other requirement for a well handling 5th wheel is that it be level. Thus 1/2 tons do not work well with 5th wheel trailers as they can not handle the pin weight that will give a well handling trailer.

[jaycocamprs]

Lantley wrote:
Wow are we confused. Why does a locomotive pull the train and not push it? The weight holds the train on the tracks.

The locomotive pulls the train because the cars are not strong enough in compression. They would crush the rear cars.