Hitch setup analysis--F150 & Bigfoot 25B25RQ

[Joe Romas]

There has been a new SAE standard for rating towing capacity that all major truck makers agreed to. Yes they have been "Grossly" over rating them..
But only Toyota is using it. But because of Ford's decision to use them only as they release newly designed models GM, Ram and Nissan are following. Shame on FORD.. Here's a link to SAE J2807
http://www.autonews.com/apps/pbcs.dll/article?AID=/20130211/OEM03/302119913#

[honda03842]

Derek,

Just for perspective, a young man in Newfoundland won a full scholarship for Memorial University in St Johns, NL, the province's best. Tuition is $4,000 a year, affordable and part of the reason NL has the highest post high school education rate in the world.

In fact the entire scholarship amounted to $70,000 plus a good summer job.

[Derek Johnson]

Good article--thanks.

The towing capacity and how it is measured should be standardized and mandated. Government regulation that help consumers make informed choices in the marketplace are a good thing.

Derek

[Derek Johnson]

Norm,

So, you are trying to depress me?

My son is going to Eastern Washington University, the least expensive of all of our state schools. The yearly cost with tuition and room/board is approximately $18,000. I pay $1,600 a month. Over the past several years the State of Washington has reduced its contribution to universities by over 50%, so tuition has risen faster than usual.

For whatever reason, and in spite of our encouragement, my son has chosen to be an average student and therefore there are no scholarships. Our local community college is an option, but it is mediocre. I want him to at least experience going away to college to see if it is for him and to see if it helps him to mature. Time will tell...

I do see students such as the one you mentioned because I have taught high school physics for the past 24 years. When my kids were little I imagined that they would be in that sort of position, but it just didn't work out that way. Maybe lousy parenting, maybe poor genetics, who knows--you tell me how to motivate every kid and we will have solved many of the world's problems.

Derek

[cpaharley2008]

If you guys like we can start a new thread on the cost of college but let's return to where we belong, thanks. That thread may start a whole new perspective on things.

[Andrew Gibbens]

Originally Posted by Brian B-P

Another way to reduce tongue weight is to extend the tongue, leaving everything where it was, except the coupler which moves forward.

As you said, this isn't really a very practical method to alter tongue weight - the amount by which the tongue must be lengthened is enormous compared to the change in the tongue weight.

And don't forget that you then need to add a lot of extra strength to the whole front of the trailer to compensate for the extra leverage of the longer tongue. That extra strength is needed all the way back to the main frame of the trailer - let's say to halfway between the front cross-member and the axle. There is absolutely no way that a tongue can be safely extended just from the exposed section forwards (in front of the body) - doing that just reduces the strength, however much steel gets added. The critical place for tongue strength is right at the front cross-member, under the front of the body.

So once you've added the extra strength a longer tongue needs, you've probably added back a lot of the tongue weight that you were trying to reduce.......

[gmw photos]

regarding the tongue weight percentage, I'm not sure I'd get too carried away with trying to reduce it much. 840 pounds, which is your measured tongue weight is 12.7% of the trailer weight, which is pretty much in the sweet spot ( IMO ) for a trailer of this design.
Regarding propane tank weights, my 20 pound tanks weigh approx 17 pounds empty, so being the math genius I am, that comes out to 37 pounds full.

And yes I agree that this all is the bane of 1/2 ton trucks: limited load capacity. If we look at much of the marketing done by the OE's, we see them bragging about tow capacities and showing a boat being pulled. Since boat trailers are typically set up with lighter tongue weights, they can brag a higher tow cap that does not really translate directly for a travel trailer or cargo trailer.
I get a lot of flack for the following, but I stick to this idea anyway: once we move into a 3/4 ton or one ton, or a one ton with training wheels, it, in my mind becomes a no brainer to go all the way to the one ton dually. The 3/4 ton trucks on offer right now do not ride any better empty than a one ton, due to the rear suspension design, so you might as well go on up to the 350/3500 series to gain the capacity. Adding the training wheels adds not only stability when loaded, it obviously raises the tire load capacity substantially. The downsides of the dually are having to buy two extra tires when the time comes, and some would argue they are not as good in snow. Empty, the snow issue can be true, I have found, but some added weight in the bed helps in the that regard. Anyway, kinda going off on a tangent. To the OP, if you are wanting to stay as close to limits as you can with the truck you have, then yes, shaving tens of pounds off here and there where you can probably makes sense.
Is it an option to try to sell the truck you have, and use that money to buy a different truck, with more capacity ? Sometimes there are deals to be had on used trucks, it's mostly about being patient and being ready to jump all over it when it comes available.

[Bruce H]

Armchair engineers,

Here are a couple of my favorite tongue weight photos:

The horse trailer tongue is hinged up and down so the tow vehicle ball does not bear any of the trailer's weight. These trailers are designed to be pulled behind a full size car such as a Lincoln or Cadillac.

The flat bed trailer tongue has an 9 1/2 foot extension u-bolted under the existing 3 1/2 foot long tongue. The total length can be adjusted by loosening the bolts and sliding the extension forward or backward. As configured in the photo the total tongue length is extended to around 10 feet. The trailer weighs 320 lbs and the ATV weighs 900 lbs. The coupler bears very little weight because of the leverage of the longer tongue. This puts no additional stress on the frame of the flat bed trailer or the receiver hitch.

[gmw photos]

Bruce,
Regarding that horse trailer, I will make one very likely correction to your wording: "these trailers WERE designed...."

"Were".
Key word there. To my knowledge nobody mass produces trailers of that design anymore. Reason is, tongue weight is a good thing when trying to achieve a stable, safe, towed trailer. That design is probably best left to just hauling things around the farm at maybe 20 mph or less.
My opinion. Armchair engineer. A fair bit of practical experience though.....

[cpaharley2008]

Actually, the horse trailer set up is no different than those double tractor trailers on the road today. In those scenarios the last trailer has no tongue weight but is merely being pulled. With the front wheels positioned up front sway has been eliminated.

[SilverGhost]

I'll take a stab at it and say both trailers were modified for other reasons.

First the ATV its easy to see that there is no way that RV could tow that trailer with out the extension. The bumper would impact the trailer and possibly the bike.

That horse trailer with semi wheels looks like it started out as center axle (single or double) and was converted to front and rear axle. Little harder to guess but the tow vehicle and particular uses that owner had were probably deciding factors. I can tell you that if the tow vehicle has some over hang then the trailer wont be cutting the corner as much.

But nice side benefit is both designs help with tongue weight.

Jason

[gmw photos]

Originally Posted by cpaharley2008

Actually, the horse trailer set up is no different than those double tractor trailers on the road today. In those scenarios the last trailer has no tongue weight but is merely being pulled. With the front wheels positioned up front sway has been eliminated.

Actually it is different. The dolly under a double ( or triple ) for a semi trailer is a fifth wheel plate. The wheels do not steer as they do on that horse trailer contraption.

Also, for whatever it's worth, I know a young fellow who drives for FedEx, and at the FedEx truck driving school in Indianapolis, they taught them that pulling a double is "far" more hazardous than a single. The double is much more likely to roll ( tip ) over in a corner.

[Jared J]

Originally Posted by gmw photos

Actually it is different. The dolly under a double ( or triple ) for a semi trailer is a fifth wheel plate. The wheels do not steer as they do on that horse trailer contraption.

Also, for whatever it's worth, I know a young fellow who drives for FedEx, and at the FedEx truck driving school in Indianapolis, they taught them that pulling a double is "far" more hazardous than a single. The double is much more likely to roll ( tip ) over in a corner.

So, what do you perceive the difference to be in a fifth wheel dolly vs. a center pivot axle? Same end result, if you ask me.

[gmw photos]

Originally Posted by Jared J

So, what do you perceive the difference to be in a fifth wheel dolly vs. a center pivot axle? Same end result, if you ask me.

You are right, the horse trailer pictured had a center pivot. I was thinking of one my buddy had that actually had steering linkage, similar to the front end under a car.

[Brian B-P]

The horse trailer is a "full trailer", rather than the more common (and essentially universal in RVs) "pony trailer" - this does completely change considerations of tongue weight. They are suitable for tow vehicles with the power and traction to pull the trailer, but not the ability to support substantial tongue weight. I think it is a useful idea, and it is very commonly used in commercial rigs; however, it may not be legal for non-commercial vehicles, depending on location, and it has other problems (backing up, tug traction). It can be built of a semi-trailer and converter dolly (typical A-train), a trailer with rear-mounted fixed axles and what we're calling a "centre pivot" steering axle or tandem axle set in front (just like a child's toy wagon or traditional horse-drawn wagon, and common in gravel trailers), or a trailer with rear-mounted fixed axles and steering front axle controlled by the drawbar. These have been discussed in FiberglassRV before, although perhaps not recently.

[Brian B-P]

Originally Posted by gmw photos

Also, for whatever it's worth, I know a young fellow who drives for FedEx, and at the FedEx truck driving school in Indianapolis, they taught them that pulling a double is "far" more hazardous than a single. The double is much more likely to roll ( tip ) over in a corner.

Sure, but the rear trailer in this A-train is being pulled by the lead trailer, a combination which is inherently less stable than pulling that same rear trailer (and dolly or whatever makes it a full trailer) directly with a tractor/tug.

[Brian B-P]

The very long tongue in Bruce's rig is a good idea for stability, and in this case allows the ball to be close to the lead trailer axle, which is very desirable. This sort of configuration is (rarely) used in some large trailers towed by commercial straight trucks. As Andrew mentioned, despite the decreased load carried by the hitch, at least some point along the trailer structure is more stressed by a longer tongue configuration, although in this case the extension "splints" that area and the trailer and there may be no adverse effect on the trailer frame. Again as Andrew suggested, to make a substantial difference for the same hitch location requires too much tongue extension to be practical in most cases.

I have attached a photo showing a rig from Thorson's Enclosed Vehicle Transport which I saw while on a trip; the trailer has a relatively long tongue, with the hitch well under the truck, in this case with a fifth-wheel hitch (perhaps due to the weight of the trailer). Sorry for the poor image quality...

The idea of moving the hitch point close to the rear axle for stability takes two forms: the relatively common over-the-truck configuration such as an Escape or Bigfoot fifth-wheel or Scamp 19'; or these unusual under-the-truck-body hitches. The Pull-Rite is actually usable for our trailers, and effectively extends the tongue with a hinge under the bumper and hardware like a typical WD hitch to minimize vertical force at the hinge point, approximating an under-mounted gooseneck. For someone with a truck limited by rear axle capacity this could be a good idea; however we are finding in this and similar examples that it is the tug's GVWR which is the problem, not the truck's rear axle capacity. Regardless of capacity, it should increase stability.

[gmw photos]

I do remember the horse trailer that my buddy had was rather beat. So at least in potential fairness to the design, it could be it was just shot. It had the linkage pieces "behind" the front axle that actually did the steering inputs. I remember laying under it and tugging and pushing and pulling on stuff....and nothing was exactly what I would call tight and snug.
He said, "towing this thing is scary".....he said it would do just kind of a gentle weave....not really a sway, but thinking, "it could become a sway really quickly if this isn't my day !" And he said when he used the brakes it would kind of do a little sideways shuffle. again, it may have just been poor setup and in need of a rebuild.....didn't matter, he didn't like it so he sold it and bought a conventional two horse trailer. At the time, which would have been early-mid '80's, he was pulling with a '78 Chevy 1/2 ton.
Man....I have not seen one of those trailers in years. Probably whatever is left of them have pretty much rusted away to nothing. Good riddance, far as I'm concerned !

[gmw photos]

Brian,
Yes, I have looked at the pull-rite, and it does indeed look like it might be a really nice functioning hitch. The only downside to it that I can see is that I'd really want to take the time to look after it from a winter salt/crud standpoint. They use a lot of salt around here where I live....ugh.....

[Bob Miller]

As long as the topic has drifted, I feel I can add a comment on:

"These trailers are designed to be pulled behind a full size car such as a Lincoln or Cadillac".

Due to a death in the family, I was just offered (for free) a full sized 2004 Cadillac Sedan DeVille with 65,000 on the clock. A beautiful (but huge) sedan that has always been serviced by the dealer. It has the NorthStar V8, actually gets over 20 MPG on the hiway and was exactly what used to be the vehicle of choice for pulling an Airstream back in the 60's....

BUT WAIT... Opened up the owners manual to the towing page and whatsitsay????

Max trailer weight: 2000 lbs, Max tongue weight 200 lbs.
That's the same rating as my 4 cylinder GMC Sonoma

So much for that idea..... Back to my new-to-me Blazer