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Weight of TT - DRY vs GVWR vs DRY HITCH

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Old 12-07-2017, 01:43 AM   #21
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No, the tongue weight wont always be the listed dry weight of 1,200 pounds (example for top trailer). In fact, it will probably never be that light.

I have a much smaller TT with a dry tongue weight of 460 (as per manufacturer specification). However after two 30 pound propane tanks and the spare tire were added to the hitch and a small battery near the front of the trailer. I weighed the tongue at the ball mount at 770 pounds using a crane scale that I have verified to be accurate within 2%. Later I decided I needed a lot more battery reserve so I changed out that small 40 pound battery for 2 golf cart batteries that came in at 120 pounds for the pair. Bringing me into the mid 800's for tongue weight. It turns out that the main storage area on this trailer is in the front. Putting just the necessary stuff that tends to be too dirty to put inside (jacks, blocks, fishing rods & tackle, axe etc.). Now I'm around 900 pounds on tongue weight on a trailer that started at 460 pounds dry tongue weight. There is no possible way I could ever have a useable trailer and maintain that 460 pounds try tongue weight.

Getting back to the 1,200 pound dry tongue weight on the one trailer you're looking at. You need to determine how much that will weigh once you set up your trailer to be useable. To keep the tongue weight from climbing too much, there are things you could do. I used to tow my TT with a Jeep GC with a max 720 tongue weight rating - so I had to make some adjustments. First, mount your spare tire(s) on the rear bumper (not too many places they can go other than the tongue and rear bumper). Next, if you have a more central place that you can house your batteries, run appropriate size wire and make a battery box somewhere near the trailers axles. There typically aren't other good places for Propane so you will probably have to leave that on the tongue, but can you make due with 1 tank instead of two? Even an empty 30 pound tank is nearly 30 pounds and full they are near 60 pounds. The spare tire(s) should balance out the propane and with the batteries over the axle you should be back close to your dry weight. My fresh water tank is over the axles and doesn't affect my tongue weight more than a few pounds. However, my grey and black are behind the axles and will actually lighten the tongue if full. The rest of your stuff just pack as close over the axles as you can. If you do all this, and know where your water tanks are and keep them full or empty depending on the desired tongue weight effect, you should be able to stay somewhat close to the dry tongue weight.

However, depending on the trailer layout, it could be harder than it sounds. I got my trailer's tongue weight down to 715 to pull with the Jeep GC with the 720 tongue weight limit. That was 15% tongue weight. However, given the short wheel base of the vehicle, even with 15% tongue weight, I could feel tractor trailers too much. I didn't help that I had a bunch of heavy stuff on or near the back bumper. So about 1/3 of the way through a 6,000 mile trip I said heck with the ratings and went for stability. Back to 900 pounds of tongue weight (18%), nothing heavy in the rear so less inertia if it did get pushed and honestly I couldn't even feel the trucks pass anymore.

I do not like the idea of playing with tongue weight to keep it "legal". When towing something on the big side for your tow vehicle, the more tongue weight you have, the more stable it will be as long as your rear end is stiff enough to take it and you have a proper weight distributing hitch. This is the reason why I sold the Jeep and just bought an F150 HDPP with twice the payload of the jeep to tow my little 27 foot (23 ft box) 4,300 dry / 6,600 GVW TT. It will easily be legal at the 18% tongue weight that I prefer to run on my travel trailer. Some set ups like a lot more tongue weight than the "recommended" 10-15%. IMHO, it should be a recommended 10%+ with the upper limit only being governed by trailer and TV ratings. On those big trailers, 1,500 - 1,600 pounds tongue weight should be good. Of course, you'll need a TV that can handle that... but we're not going to talk about the vehicle.

Last edited by Gladehound; 12-07-2017 at 01:49 AM.
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Old 12-07-2017, 06:43 AM   #22
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If a trailer is well designed(load properly distributed) there’s no reason why it should not be stable at 65mph with 10-12% tongue weight. Add a TV with adequate mass and wheelbase and you have a good combination. There’s no doubt though that some trailers will need more tongue weight to be stable, poor design is the reason and this is probably the last thing most people think about when buying a trailer. You can have two trailers of the same weight and length yet one could be stable and the other sway like he!!. Even with my limited knowledge of physics I would not consider a trailer that’s more than 1.5x the weight of the TV since the possibility of instability becomes greater. You want a system that will dampen sway out naturally with its critical speed above normal highway speeds, not one on the ragged edge relying on hitch sway control and ESC.
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Old 12-07-2017, 07:46 AM   #23
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If a trailer is well designed(load properly distributed) thereís no reason why it should not be stable at 65mph with 10-12% tongue weight. Add a TV with adequate mass and wheelbase and you have a good combination. Thereís no doubt though that some trailers will need more tongue weight to be stable, poor design is the reason and this is probably the last thing most people think about when buying a trailer. You can have two trailers of the same weight and length yet one could be stable and the other sway like he!!. Even with my limited knowledge of physics I would not consider a trailer thatís more than 1.5x the weight of the TV since the possibility of instability becomes greater. You want a system that will dampen sway out naturally with its critical speed above normal highway speeds, not one on the ragged edge relying on hitch sway control and ESC.
10-12% seems like a somewhat arbitrary amount. I realize the testing in the US is done at 10%. In Europe, 5-6% is normal, and they tow travel trailers with mid-size station wagons. But they drive slower with those trailers than people do here. Agree that a combo should be stable enough at 10-12% that any sway imposed by an outside force should naturally dissipate below the normal trailering speed of 65mph. However, with a vehicle on it's limits (Like the set up the OP is proposing and like when I towed my TT with my Jeep) additional tongue weight beyond the US standard of 10% can transfer additional weight from the trailer to the tow vehicle to be distributed across the front and rear of the tow vehicle with a WDH, making the entire rig less susceptible to initial movement due to wind. It effectively makes the tow vehicle heavier and the trailer lighter. I hear people talking about the bow wake from trucks all the time and at 18% TW pulling a 27 foot TT with a Jeep, I can't even feel a truck pass. As long as weight is distributed properly and all weight ratings are good, I can't think of any situation where more tongue weight wouldn't make a combination even more stable than the arbitrarily accepted level of stability afforded by the US testing standard of 10%.
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Old 12-07-2017, 08:43 AM   #24
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In theory adding tongue will increase the dynamic stability of the the trailer even beyond 18% but the added tongue will eventually cause TV rear axle weight to exceed rated values. In contrast adding extra load to the TV axles will decrease the understeer gradient increasing static instability of the TV. It becomes a balance of maintaining the reasonable stability of both pieces of the system. Adding WD does help but only to a point, once TV axle loads reach a saturation point adding more weight will reduce grip.
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Old 12-07-2017, 09:22 AM   #25
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Last edited by Rosey17; 12-07-2017 at 09:31 AM.
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Old 12-07-2017, 10:54 AM   #26
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So... where is that video of the guy towing too big of a trailer that flipped over? OP claims to know the trucks, yet plans to pull one of these monsters with an F150?

For weight on the trailer, #1 most important aspect is TW. 10-15%, no less. When referring to RV trailers, mass is only a small factor, frontal and side area are the largest factors to consider. Not only do you have frontal area to consider when towing, as there are limits placed on each truck on how large it can be, but also side area to consider. The longer the trailer, the larger that is when cross winds hit it, trucks pass it, etc. If you don't have the mass up front to counter it, no matter how good your hitch is, or how good the setup is, that trailer WILL move the truck, and weight distribution will not play any factor into that with a proper setup.

In short, if you really really want one of these monsters, get it AFTER you replace the truck, not before, the F150 is not the right truck to tow it with, no matter how little towing you wish to do!

Oh yeah, here it is.


Shoot, I wouldnt even attempt a trailer that size with an HDPP long bed! It is just way too freaking long.
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Old 12-07-2017, 12:00 PM   #27
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Trailer to TV mass ratio is not just a small factor, it’s a key parameter in calculating the sway damping ratio of a system. It’s basic laws of physics that vehicle manufacturers are ignoring in favor of ESC systems. I guarantee an accident investigator will use damping ratio in effort to determine the cause of a Truck/trailer accident.
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Old 12-07-2017, 04:58 PM   #28
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Quote:
Originally Posted by adammjarvis View Post
Get your facts straight....
...You're either a special kind of stupid unable to understand/read or you're just trolling. I'll let you decide which one applies best for you
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Originally Posted by acdii View Post
So... where is that video of the guy towing too big of a trailer that flipped over? OP claims to know the trucks, yet plans to pull one of these monsters with an F150? .......

.....Shoot, I wouldnt even attempt a trailer that size with an HDPP long bed! It is just way too freaking long.
Whoa there, ACDII! Don't be disrespecting the OP ...he will accuse you of being a special kind of stupid, a troll or the worst kind....A SPECIAL KIND OF STUPID TROLL (SKOST)!!! (Just my opinion but I think you're a SKOST for thinking of safety...You take all the risk away from others on the road) HAHAHA!

That video is a great example of that can go wrong either poorly loading a trailer and/or overloading the tow vehicle.

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Old 12-07-2017, 04:58 PM   #29
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The % tongue weight will determine the position of the CG which will be forward of the axles at 11-15%. You can move the weight in front and behind the axles and still achieve a good CG location but the further it gets away from axles the higher the yaw inertia. If you donít know what yaw inertia is just Google it. If it were me I would not pick either one of them for the short wheelbase lighter truck you have. I attached a picture of my trailer layout with the approximate axle location. All the heavy items are close to the axles, the fresh water tank centered over the axles offset to the curb side. This trailer is very stable while towing and has done many miles with only WD and no sway control though my current setup does have built in sway control. The trailer is 32.5 ft and has a 8500lb GVWR.
I'll google yaw inertia - thank you for the lead.

Going back to the trailer.. the axles are located by the lines marked. This is based off of outside images where the wheels are located at on the trailer

Thankfully the shower/toilet is there so it's safe to assume the gray/black tanks will be right over the axles which really doesn't mean much as those will typically be empty in tow. I'd assume the fresh water tank will be in that area tho. Unsure where.
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Weight of TT - DRY vs GVWR vs DRY HITCH-screen-shot-2017-12-06-11.54.17-am.png  
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Old 12-07-2017, 05:09 PM   #30
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No, the tongue weight wont always be the listed dry weight of 1,200 pounds (example for top trailer). In fact, it will probably never be that light.

I have a much smaller TT with a dry tongue weight of 460 (as per manufacturer specification). However after two 30 pound propane tanks and the spare tire were added to the hitch and a small battery near the front of the trailer. I weighed the tongue at the ball mount at 770 pounds using a crane scale that I have verified to be accurate within 2%. Later I decided I needed a lot more battery reserve so I changed out that small 40 pound battery for 2 golf cart batteries that came in at 120 pounds for the pair. Bringing me into the mid 800's for tongue weight. It turns out that the main storage area on this trailer is in the front. Putting just the necessary stuff that tends to be too dirty to put inside (jacks, blocks, fishing rods & tackle, axe etc.). Now I'm around 900 pounds on tongue weight on a trailer that started at 460 pounds dry tongue weight. There is no possible way I could ever have a useable trailer and maintain that 460 pounds try tongue weight.

Getting back to the 1,200 pound dry tongue weight on the one trailer you're looking at. You need to determine how much that will weigh once you set up your trailer to be useable. To keep the tongue weight from climbing too much, there are things you could do. I used to tow my TT with a Jeep GC with a max 720 tongue weight rating - so I had to make some adjustments. First, mount your spare tire(s) on the rear bumper (not too many places they can go other than the tongue and rear bumper). Next, if you have a more central place that you can house your batteries, run appropriate size wire and make a battery box somewhere near the trailers axles. There typically aren't other good places for Propane so you will probably have to leave that on the tongue, but can you make due with 1 tank instead of two? Even an empty 30 pound tank is nearly 30 pounds and full they are near 60 pounds. The spare tire(s) should balance out the propane and with the batteries over the axle you should be back close to your dry weight. My fresh water tank is over the axles and doesn't affect my tongue weight more than a few pounds. However, my grey and black are behind the axles and will actually lighten the tongue if full. The rest of your stuff just pack as close over the axles as you can. If you do all this, and know where your water tanks are and keep them full or empty depending on the desired tongue weight effect, you should be able to stay somewhat close to the dry tongue weight.

However, depending on the trailer layout, it could be harder than it sounds. I got my trailer's tongue weight down to 715 to pull with the Jeep GC with the 720 tongue weight limit. That was 15% tongue weight. However, given the short wheel base of the vehicle, even with 15% tongue weight, I could feel tractor trailers too much. I didn't help that I had a bunch of heavy stuff on or near the back bumper. So about 1/3 of the way through a 6,000 mile trip I said heck with the ratings and went for stability. Back to 900 pounds of tongue weight (18%), nothing heavy in the rear so less inertia if it did get pushed and honestly I couldn't even feel the trucks pass anymore.

I do not like the idea of playing with tongue weight to keep it "legal". When towing something on the big side for your tow vehicle, the more tongue weight you have, the more stable it will be as long as your rear end is stiff enough to take it and you have a proper weight distributing hitch. This is the reason why I sold the Jeep and just bought an F150 HDPP with twice the payload of the jeep to tow my little 27 foot (23 ft box) 4,300 dry / 6,600 GVW TT. It will easily be legal at the 18% tongue weight that I prefer to run on my travel trailer. Some set ups like a lot more tongue weight than the "recommended" 10-15%. IMHO, it should be a recommended 10%+ with the upper limit only being governed by trailer and TV ratings. On those big trailers, 1,500 - 1,600 pounds tongue weight should be good. Of course, you'll need a TV that can handle that... but we're not going to talk about the vehicle.
Rather than give you a click thanks (which I'll do anyways) I wanted to personally thank you for your insight and experience. Thank you.

The propane tanks, per manufacture, are included in the dry weight as empty tanks. I forgot about batteries. However I can re-run those anywhere as needed. I'd rather them be installed somewhere inside the trailer for added warmth (trailer is "four seasons rated" - probably just three seasons if we're realistic)

The video I posted a few pages back - dude has similar trailer in same weight range. I'm not sure how his trailer was loaded but he did demonstrate how he didn't feel a big rig passing him by. I wish there were more specs about his setup/truck/trailer.
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