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?

[wilber1]

fj12ryder wrote:
FWIW if I tow with the toys onboard my pin weight percentage drops from 22% to 19%. However the ride improves considerably with less chucking and jerking. This is on a 15,000 lb. toyhauler.

So perhaps adding weight to the pin may not always improve the ride.

Too much of anything is rarely a good thing.

[N-Trouble]

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. 🙂

I'm an engineer... And yes the above example is not quite accurate. The numbers would only hold true if the extra 1000lbs were added exactly at the pivot point (axles). Weight added behind axles will reduce pin weight. PERIOD... How much depends on the weight and how far back from the pivot point it is added.

Pin weight is determined by a COMBINATION of how the weight is distrubuted along the length of the trailer + where the pivot point (axles) are located in relation to the pin. Think teeter-totterer...

[Cummins12V98]

stickdog wrote:
Here I thought my smooth ride was my b&w hitch and glide ride pin box and now you tell me is my 24.41% pin wt.

All the above!

[Me_Again]

ryhed 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.

A towable RV weight needs to be in the front to keep the nose down. If the nose or pin is too light the trailer would chuck/bounce too much and attempt to lift off the hitch as the trailer traveled down the road. The RV would be very unstable as you traveled. Having a heavier nose keeps the front of the trailer down and helps the pin maintain contact with the hitch
Yes axle placement enters the equation. The axle does set up the pivot point to help achieve the desired (20-25% of loaded weight) pin weight.
But cargo placement is equally as in important. Putting too much cargo or weight on the rear will make for a light pin and create an unstable towing experience.

+1, except a locomotive neither pulls or pushes cars, they are merely generators to turn the electric motors located under the wheels of each car.

ON WHICH planet is that?

Chris

[fj12ryder]

FWIW if I tow with the toys onboard my pin weight percentage drops from 22% to 19%. However the ride improves considerably with less chucking and jerking. This is on a 15,000 lb. toyhauler.

So perhaps adding weight to the pin may not always improve the ride.

[fj12ryder]

ryhed 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.

A towable RV weight needs to be in the front to keep the nose down. If the nose or pin is too light the trailer would chuck/bounce too much and attempt to lift off the hitch as the trailer traveled down the road. The RV would be very unstable as you traveled. Having a heavier nose keeps the front of the trailer down and helps the pin maintain contact with the hitch
Yes axle placement enters the equation. The axle does set up the pivot point to help achieve the desired (20-25% of loaded weight) pin weight.
But cargo placement is equally as in important. Putting too much cargo or weight on the rear will make for a light pin and create an unstable towing experience.

+1, except a locomotive neither pulls or pushes cars, they are merely generators to turn the electric motors located under the wheels of each car.

Good joke. 🙂

[ryhed]

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.

A towable RV weight needs to be in the front to keep the nose down. If the nose or pin is too light the trailer would chuck/bounce too much and attempt to lift off the hitch as the trailer traveled down the road. The RV would be very unstable as you traveled. Having a heavier nose keeps the front of the trailer down and helps the pin maintain contact with the hitch
Yes axle placement enters the equation. The axle does set up the pivot point to help achieve the desired (20-25% of loaded weight) pin weight.
But cargo placement is equally as in important. Putting too much cargo or weight on the rear will make for a light pin and create an unstable towing experience.

+1, except a locomotive neither pulls or pushes cars, they are merely generators to turn the electric motors located under the wheels of each car.

[stickdog]

Here I thought my smooth ride was my b&w hitch and glide ride pin box and now you tell me is my 24.41% pin wt.

[gitane59]

transamz9 wrote:

Jim-Linda wrote:

DSteiner51 wrote:

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!!

Would you care to explain the loser comment?

Jim

I didn't make the loser post but I will tell you that to much tongue weight can have a negative effect in the towing experience no matter how much TV you have. If you go over 50% or so it feels like you are dragging it instead of it rolling behind you.I haul heavy equipment for a living so I know the effects of an improperly loaded trailer;)

And too little pin weight regardless of how heavy the TV is will cause the trailer to bounce and chuck on the hitch pin of the TV causing a very poor tow quality. Also with an abnormally light pin weight the trailers stability will be sacrificed potentially causing trailer sway.
So while the "LOSER" comment may not have been politically correct I think what he was trying to say was
DING, DING, DING 2 un-winners.:D

BTW my Newmar is between 23-27% pin weight depending on how I load it, it tows wonderfully stable with a very smooth ride in the TV.
I appreciate how far back in the frame that Newmar chose to locate my axles as that contributes tremendously to how well and smoothly it tows.

[AniJet]

Wadcutter wrote:
Some people must have failed basic high school physics. Simple fulcrum and lever formula. The wheels would be the fulcrum.

To expand a little on Wad's post, it's the relationship of the center of gravity to the axles. Adding or moving tare moves the CG. If the CG is right over the axles there is no pin weight (balanced). Move the CG forward and the pin weight will increase.

As to having enough TV, even a HDT towing a rig with insufficient pin weight will find the trailer swaying. It may not move the TV around because of its weight but the view in the mirror wouldn't be pretty.

[transamz9]

Jim-Linda wrote:

DSteiner51 wrote:

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!!

Would you care to explain the loser comment?

Jim

I didn't make the loser post but I will tell you that to much tongue weight can have a negative effect in the towing experience no matter how much TV you have. If you go over 50% or so it feels like you are dragging it instead of it rolling behind you.I haul heavy equipment for a living so I know the effects of an improperly loaded trailer;)

[MTPockets1]

If a man is in the woods all alone and talks, is he still wrong?

[Wadcutter]

Some people must have failed basic high school physics. Simple fulcrum and lever formula. The wheels would be the fulcrum.

[Jim-Linda]

DSteiner51 wrote:

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!!

Would you care to explain the loser comment?

Jim