% Of Weight That Is Pin Weight

[Cat320]

Saw this on another forum...sounded interesting, and makes sense.

When adding weight to the storage areas of 5ers, the question always arises as to how much of that weight goes on the pin as pw. Here is what a mechanical engr on the other forum stated:

1. Measure the distance from the center of the two axles to the pin.
2. Weigh the 'stuff' you are storing.
3. Measure the length from the center of the two axles to the center of mass of the 'stuff' you are storing.
4. Compute the percentage of distance from the measurement in #3 as compared to the measurement in #1.

If #1 is 20' and #3 is 12', #3 is 60% of the distance from #3 to #1. Therefore, if the weight added is 500 lbs, 60% of it, or 300 lbs goes to pw. Don't know how accurate this is, but at least it's a ball park figure.

[indy roadrunner]

Lets see, have a brew first, now where is that calculator? Oh found another brew, lets see what is that formula again? Honey where is the tape measure? Man that is a lot of work have another brew. Man this don't make sense - Honey would you run the unit down to Flying J and scale it for me while I try to figure this formula out? And pick another case of Bud on the way home.

I'm sorry, that might be good information but still seems a lot simpler to just go to the scales at your local truck stop. Some math experts might appreciate the formula and process.

[Bill and Ann]

Phill: Exactly right. I weighed my unit at Flying J. the day I got it. Empty except for the propane. I reweigh it continually to see how much junk I am lugging around. I also weigh it hooked and unhooked to get my pin weight. Don't even need a calculator to subtract a couple of figures. But don't give up on the Bud.

[dsprik]

Cat320, I like the figures. I would love to calculate the numbers, then run the CAT scales, but it's hard to run the CAT scales if your trying to speculate if it would be better to put a 3000 Honda/3500 Kipor in your truck bed, or in your basement compartment. Remember, a lot of us, don't have a lot of pin weight to get sloppy with on our 2500s/F250s. That formula could be handy to estimate.

I think the formula might be useful on occassion.

[Wrenchtraveller]

Loaded up with fresh water and a lot of stuff we really did not need but we had accumulated after 44 days on the road my 2955 RL weighed 12300 pounds. 9700 on the trailer axles and 2600 pounds on the pin. My SRW 05 F350 has a GVWR of 11200 and I was at 11080 with my auxilary fuel tank (50Gal)
full, tools, two big mutts and Donna and I but again we do travel heavier than most people but I need this stuff so I am real happy I traded in the 04 F350 SRW 9900 GVWR model as it would have been overweight by 1000 pounds.
The 05 F350 loves the 2600 pounds of pin weight and it just levels it out and makes it ride more like a car or a Chev pickup .

[richfaa]

We have pretty much the same truck as Wrenchtraveller with the 12,600 lb GVWR package. We did the scale thing when we got the 3400, can't remember all the numbers now but remember the Tv was 7350lbs. GCWR of 23,500lbs and fifth wheel tow of 16,100lbs .We will weigh in one more time before we leave for our trip July 4th but we are not to concerned with the weights..Oh..the truck/ camper sits perfectly level/// good set up by the dealer.

[Cat320]

The original poster on the other forum was adding a few small but fairly heavy pieces of equipment...washer/dryer, generator. He wanted a ballpark estimate of what it would do to his pw without having to go to the scale.

No doubt the scale is the best way to go for serious wieghing.

[HomeOnTheRoad]

That is a good formulat to know. It helps to be able to know how much weight will go on the hitch and how much on the axles. Thank you for the information.

[sreigle]

Thanks for the information. I could also see using that formula to determine how much impact on pinweight moving an item from one area of the coach to another would make. And how much difference on pinweight carrying 1/3, 2/3, or a full freshwater tank would make. Thanks.

[sheiba1]

I guess with a little reconfiguring of the formula you could deduct from the pin weight when you load stuff behind the axle’s. That or get a larger bathroom scale for under all 4 wheels?
Rich and Marita

[Wrenchtraveller]

Can anyone remember the recommended minimum percentage for a Fifth wheel?
I believe you can put up to 25% of your Trailer weight on your Pin.

I know a conventional trailer is supposed to have around 10 % on the hitch ball and I know Fifth wheels have a minimum percentage point.

In my case my pin weight is about 21% of the trailer weight. 21% of 12300 pounds is 2583 pounds.
I am sure happy with the ride and handling of my unit so I guess this is a good weight ratio.

[Cat320]

The Chevy brochure recommends 10% to 15% for TTs and 15% to 25% for 5th wheels.

[dsprik]

Don, I've consistently heard the 20% figure as the optimal load on the pin.

[Wrenchtraveller]

http://www.campingworld.com/tLibrary....cfm?ID=112411

This article as well as many others I have read say that up to 25% is fine. When you load up your fiver, your pin weight will increase and trying to load in a manner that will lighten the pin is really not that easy or practical to do.

[rickfox]

Don't forget folks that all TV's have maximum rear axle load limits. Placing 25% of a 12,000# trailer on the hitch pin is 3,000# This will exceed the maximum load for all 3/4 ton Chevys. A 14,000# trailer at 25% pin weight is 3500#. This is guaranteed to overload your TV.

Time to do a lot of load rearranging to get those pin weights down to a reasonable limit - or you will start blowing TV rear tires.

[David and Jo-Anna]

Just goes to show how far off the mark is the pin weight figure Montana provides for the 3400. If you apply the 15%-25% figures to the 3400's 13,975# GVWR, the pin weight should be in the range of 2096#-3493#. So if you actually tried to limit your pin weight to 1975#, you'd be lighter than the low end of the range recommended by truck manufacturers. Dumb!!

[Cat320]

In my 2006 Spec Sheet, it lists the actual weights and the actual percentage of it that is pw. For the 3400 it lists the pw as 17% of the shipping weight.

David, don't be too hard on Keystone, every brochure in the RV industry lists pw as dry pw. They all want to make the pw appear as light as possible so you think you can haul it with a 3/4 ton...works doesn't it?

[David and Jo-Anna]

Bert:

Sorry if I was too hard on Montana about their dumb pin weight number. Its not that I object so much to their offering up that number for public comparision to the dry pin weights offerred by other manufacturers. It's that they then turn aroung and use that irrelevant number as the basis for calculating their GVWR (dumb pin weight + 12,000# axle load=GVWR), and that GVWR can get some owners in trouble if they get in an accident and their rig is over the artificially low GVWR limit.

Dumb--and damaging to us.