Tongue Weight

[Fergy5244]

Getting ready to down size this spring from our class A motorhome to a travel trailer .
Just doing research now, want to get trailer first then tow vehicle.
I know tongue weight is a very important part of the safe towing experience. I have seen tongue weighing devices, but they only weigh the tongue when not hooked up to tow vehicle. The magic number is 10% of trailer weight should be tongue weight. Weight distribution systems can move 20 to 30% of tongue weight back to axels of trailer.
So if I weigh tongue weight before hooked up to vehicle and weight distribution system that reading could be 20 to 30% off.
So how do you get a accurate tongue weight when attached to tow vehicle?
Am I thinking correctly?

[tdf-texas]

Originally Posted by Fergy5244

Getting ready to down size this spring from our class A motorhome to a travel trailer .
Just doing research now, want to get trailer first then tow vehicle.
I know tongue weight is a very important part of the safe towing experience. I have seen tongue weighing devices, but they only weigh the tongue when not hooked up to tow vehicle. The magic number is 10% of trailer weight should be tongue weight. Weight distribution systems can move 20 to 30% of tongue weight back to axels of trailer.
So if I weigh tongue weight before hooked up to vehicle and weight distribution system that reading could be 20 to 30% off.
So how do you get a accurate tongue weight when attached to tow vehicle?
Am I thinking correctly?

A WDH doesn't change the tongue weight - it just redistributes it off the TV's rear axle.

"Weight distribution works to distribute the tongue weight of a trailer up to the front axle of the tow vehicle so that it will sit more level and handle/brake better.

That being said the systems do not "reduce" tongue weight or allow you to tow beyond the capacities of the vehicle. The tension on the spring bars essentially lifts up on the tongue, figuratively "holding" some of the tongue's weight. This causes a shift in the distribution of the weight off of the vehicle's rear axle to all of the axles in the entire setup."

https://www.etrailer.com/question-180152.html

[Centex]

IOW, insofar as ensuring the goal of 10-15% of the Gross Loaded Trailer Weight on the tongue (to avoid sway issues) even if using a WDH .....

With a tongue scale such as the Sherline type, measure the weight at the bare tongue unhitched from the vehicle with the tongue at the height it will be when fully hitched with the WDH tensioned / adjusted.

Please note that (IMO) 10% of the Gross Loaded Trailer Weight is not the "magic number", it is the minimum you should seek - especially with a WDH to correct for vehicle sag, more can help even better ensure elimination of any propensity toward dread trailer-sway.

[John in Santa Cruz]

as an example, my current truck specifies a WDH is advised above a 6500 lb trailer. as my Escape 21 weighs at most 4500 lbs, I've found no need for a WDH. 1000s and 1000s of miles over all sorts of gnarly mountain roads and I agree. no need.

[Rossue]

Here we go again with WDH: you may not need it, yet may like the big reduction in sag & porpoising. Used it on a Yukon which really didn't need it with stiff rear suspension- and now with Expedition which has independent rear suspension and much softer.

[Centex]

Originally Posted by John in Santa Cruz

as an example, my current truck specifies a WDH is advised above a 6500 lb trailer. as my Escape 21 weighs at most 4500 lbs, I've found no need for a WDH. 1000s and 1000s of miles over all sorts of gnarly mountain roads and I agree. no need.

Respectfully, that info isn't an example of any of the issues or phenomena queried by the OP or contained in the two previous replies which went to the OP's question.

Just noting that the OP didn't ask about use of a WDH, just how to measure tongue weight if one were used as it relates to tongue weight goals pertaining to sway-prevention.

That's a matter of basic concept / principles and can be answered without any info or assumption at all about the trailer and its weight(s) or the TV and its capabilities; and it's a question clearly distinct from the issue of WDH necessity / desirability / appropriateness for any given rig of trailer and TV.

So why take the thread there? Especially without first asking for info about the OP's intended rig to give some sensible context / basis for comment in that direction?

[John in Santa Cruz]

The Sherline tongue scale is the gold standard, but they are rather expensive. For the few times I've wanted to verify my tongue weight, I got this cheap spring scale, they are mostly sold in Australia, and Canada, and are kind of hard to find in the USA...

like, here it is at Princess Auto in Canada for C$35, https://www.princessauto.com/en/trai...t/PA0008916801

I found these somewhere stateside a few years ago for a reasonable price, and bought one and it works great. mine is marked in kg so I need to convert, but no biggie.

[edit] ah HAH! I got mine in early 2019, right here, https://www.ebay.com/itm/Trailer-Tow...t/192874481388

$36.

scale must be square vertical to be accurate. trailer frame should be level, so use blocking to achieve this. scale measure sin KG, so convert (KG/2.2 == Pounds), its good from like 220 lbs up to about 750 lbs, so easily covers our FG trailers.

When I've used it, I've found I had to jack the trailer up quite a bit to get the scale under it, but once the weight was on the scale, it was pretty level. I have it parked on a slight slope, where it slopes up in front.

[Brian B-P]

Anyone interested in this who hasn't read and understood Tom's post should go back and make sure that they understand it.

The actual load on the hitch ball isn't important to towing stability. Hitch weight is just the most easily measured indication of where the centre of mass of the trailer is relative to the axle(s): further forward means more hitch weight, and further forward is more stable.

So, yes, the tongue weight as measured with no WD equipment connected, and with the tongue at the same height as it is while being towed (which should be level) is the "true" or "correct" tongue weight.

While all conventional (not 5.0) Escape models have roughly 10% of their weight on the tongue when empty, they should have a more front-biased distribution when loaded. Some trailers are intended to be towed at much lower tongue weights, and are stable in this condition, but that's not the case for a typical North American travel trailer such as an Escape.

[John in Santa Cruz]

Originally Posted by Brian B-P

....Some trailers are intended to be towed at much lower tongue weights, and are stable in this condition, but that's not the case for a typical North American travel trailer such as an Escape.

yeah, the typical european caravan has a relatively long tongue, and is stable with relatively little tongue weight.

[John in Santa Cruz]

the key thing my 'princess' style spring scale has shown me, that with our typical load, and our bicycles on a rack on the back, our tongue weight is only 400 lbs, with a trailer thats likely pushing 4500, and yes, it feels just a little bit 'lighter' behind the F250. not enough to do anything dangerous, just not quite optimal. we're loading all the heavy canned foods and beverages under the bed for travel now, and that helps a lot. minimizing the use of the storage under the rear dinette to things like kleenex and paper towels. leaving the upper rear cabinets empty til we arrive, then transfering food stuffs out fo the crates under the bed into said cabinets.

I strive to keep the tongue weight above 450 lbs, and usually can do it.

[Brian B-P]

Originally Posted by John in Santa Cruz

yeah, the typical european caravan has a relatively long tongue, and is stable with relatively little tongue weight.

Not only is the tongue relatively long, but it doesn't have propane tanks, batteries, or a cargo box full of stuff on the tongue... or a rack of stuff on the back. The key to stability with lower tongue weight (commonly 8% or even less) is keeping the mass near the middle, not out at the ends; it would be hard to arrange that with an Escape (although it could be done), so the required tongue weight is higher.

[Defenestrator]

Speed is the biggest difference on the non-US trailers. They sacrifice some stability in tongue weight but make it up by keeping speeds down. Various countries have towing speed limits of 62MPH or even 50MPH. In practice, there seems to be more expectation of slow speeds in general when towing as well.

[Brian B-P]

Originally Posted by Defenestrator

Speed is the biggest difference on the non-US trailers. They sacrifice some stability in tongue weight but make it up by keeping speeds down. Various countries have towing speed limits of 62MPH or even 50MPH. In practice, there seems to be more expectation of slow speeds in general when towing as well.

I agree... but there are other trailer design differences as well. They have the mass more concentrated to toward the middle, which improves stability (by reducing the polar moment of inertia, if you're interested in the physics); they generally don't have heavy stuff hanging off both ends as is common here.

The speed limit allowed in some European countries depends on other factors affecting stability, such as the use of a sway damping device (typically a friction-on-ball coupler), active sway control (using the trailer's brakes or the tow vehicle's stability control system), or better damping in the trailer suspension (shock absorbers added to rubber-sprung independent suspension similar to Torflex).

[Toad]

One way to determine your load on your tongue, pull your tow vehicle onto a vehical scale without travel trailer and get a weight, then hitch up your travel trailer and pull back onto the scale making sure only the tow vehicle is on the scale "not the trailer", you will get an increased weight with the trailer hitched up, the difference between the solo vehicle and hitched vehicle is your added tongue weight.

Originally Posted by Fergy5244

Getting ready to down size this spring from our class A motorhome to a travel trailer .
Just doing research now, want to get trailer first then tow vehicle.
I know tongue weight is a very important part of the safe towing experience. I have seen tongue weighing devices, but they only weigh the tongue when not hooked up to tow vehicle. The magic number is 10% of trailer weight should be tongue weight. Weight distribution systems can move 20 to 30% of tongue weight back to axels of trailer.
So if I weigh tongue weight before hooked up to vehicle and weight distribution system that reading could be 20 to 30% off.
So how do you get a accurate tongue weight when attached to tow vehicle?
Am I thinking correctly?

[Brian B-P]

Originally Posted by Toad

One way to determine your load on your tongue, pull your tow vehicle onto a vehical scale without travel trailer and get a weight, then hitch up your travel trailer and pull back onto the scale making sure only the tow vehicle is on the scale "not the trailer", you will get an increased weight with the trailer hitched up, the difference between the solo vehicle and hitched vehicle is your added tongue weight.

Yes, that works well... as long as you are not using a weight-distributing hitch system.

[Toad]

So it was my understanding that even with a weight distribution system, that would not change the load on your hitch, just disperse the load, am i wrong?

Originally Posted by Brian B-P

Yes, that works well... as long as you are not using a weight-distributing hitch system.

[yangstyle]

Originally Posted by Toad

So it was my understanding that even with a weight distribution system, that would not change the load on your hitch, just disperse the load, am i wrong?

I believe the WDH will distribute the weight to the TV front axle as well as the trailer axle or axles so if you do not weigh the trailer when it is hooked up the second time then some of the weight will not be in the calculation.

[Brian B-P]

Originally Posted by Toad

So it was my understanding that even with a weight distribution system, that would not change the load on your hitch, just disperse the load, am i wrong?

WD just redistributes load between axles, but because it shifts some load from the tug's rear axle to the trailer axle, it changes the value you will get with this method.

[Doug2000]

There are many good youtube videos on trailers, capacity and weights. To get a true idea, you need to weigh at a CAT scale 3 times. Truck, Truck and Trailer, Truck and Trailer with a weight distribution hitch.

Here is one good video

https://www.youtube.com/watch?v=qwFLOBrADBs

This guy didn't do it properly, but you get the idea. You want each axle on its own scale.

https://www.youtube.com/watch?v=-Maw2AMveNw