Weight and Balance

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Re: Weight and Balance

Postby Tom&Shelly » Tue Mar 27, 2018 10:16 pm

dancam wrote:
Tom&Shelly wrote: Just yesterday we tried to back our HF utility trailer loaded with junk, up our (uphill) driveway, and Shelly's Jeep complained about overheating transmission fluid. First time we'd seen that. She researched it last night, and now we plan to upgrade or add a 2nd cooler. A gauge is a very good idea.

Tom


Just a larger cooler for the transmission should be all you need, not a second one. Its probably a common modification so if you google what others use on that particular jeep you should find a good solution pretty quick.

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Okay. Yes, it sounded (from what she tells me) that a lot of folks who 4 wheel do it. Thank you!

Tom
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Re: Weight and Balance

Postby John61CT » Wed Mar 28, 2018 6:54 am

Tom&Shelly wrote:
John61CT wrote:Well my point is, to the extent you weigh down your back axle, the less capacity you have for towing (safely)


Yes, we will keep it between 10 and 15%. When I was planning the put the batteries in front, it was getting up to 18% and a bit over 200 lbs.

Tom
I also meant more the Gross Combined Vehicle Weight Rating (GCVWR).

Best to stay **well below** on that for safety.

If you regularly get over 60-70%, IMO start considering another TV.

A take it slow meantime.
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Re: Weight and Balance

Postby Tom&Shelly » Wed Mar 28, 2018 9:39 am

I also meant more the Gross Combined Vehicle Weight Rating (GCVWR).

Best to stay **well below** on that for safety.

If you regularly get over 60-70%, IMO start considering another TV.

A take it slow meantime.


Hmm, okay, if I understand what you're saying, we may be in trouble. Is GCVWR the same as GCWR?

Our 2 door automatic Jeep Wranger owner's manual says the GCWR is 6032 lbs. Googling online says the curb weight is 3760 lbs. Our trailer is ~1550 lbs. Figure about 600 lbs for us, our winch, tongue weight and misc. cargo in the Jeep and we're up to 98% of the GCWR. Am I doing that correctly?

Tom
Last edited by Tom&Shelly on Wed Mar 28, 2018 9:51 am, edited 1 time in total.
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Re: Weight and Balance

Postby dancam » Wed Mar 28, 2018 9:43 am

John61CT wrote:I also meant more the Gross Combined Vehicle Weight Rating (GCVWR).

Best to stay **well below** on that for safety.

If you regularly get over 60-70%, IMO start considering another TV.

A take it slow meantime.
I have never heard anyone say that before, their vehicle empty without them in it is 60% and its at 70% with them and their bit of gear inside it, no trailer, 4 adults with no gear is 75%. Whats your reasoning?

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Re: Weight and Balance

Postby John61CT » Wed Mar 28, 2018 1:12 pm

If your total combined weight is near or right at the maximum specified, you are technically "safe" and legal.

Maybe for short trips weekending, keeping everything well maintained.

But if that's the way you're rolling day after day, thousands of miles, even weeks or months at a time, to me you're playing with fire, rolling the dice, not just yours and loved ones but others on the road.

A fat friend, a few extra water jugs and coolers in the back, worn brakes or a tire blows, you're going a bit too fast or are tired, slippy road, heavy winds or a big pothole...

all it takes is 2-3 factors to coincide.

Compared to a nice heavy TV pulling half what it's max rated for, which one would you rather your young only child riding in?

If you ask, what have children got to do with it? my answer is: exactly!
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Re: Weight and Balance

Postby Tom&Shelly » Wed Mar 28, 2018 1:23 pm

Thank you John,

While not exactly what I wanted to hear, it sounds like good advice, which is really what I'm looking for by posting here.

Towing long distances, we also want to feel comfortable with the rig. Guess there may be a larger tow vehicle in our future.

Tom
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Re: Weight and Balance

Postby John61CT » Wed Mar 28, 2018 2:06 pm

Or maybe worth going to more trouble reducing weight.

Think like a backpacker, maybe not every ounce, but make every pound count, most carry stuff they don't really need; be ruthless, aluminum, composites rather than steel, foam rather than wood, etc.

Or if nothing else just being aware you're pushing limits, ease off on the lead foot and set a more leisurely travel schedule, be conservative about weather conditions, check brakes and tire conditions more diligently, etc
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Re: Weight and Balance

Postby dancam » Wed Mar 28, 2018 9:04 pm

John61CT wrote:If your total combined weight is near or right at the maximum specified, you are technically "safe" and legal.

Maybe for short trips weekending, keeping everything well maintained.

But if that's the way you're rolling day after day, thousands of miles, even weeks or months at a time, to me you're playing with fire, rolling the dice, not just yours and loved ones but others on the road.

A fat friend, a few extra water jugs and coolers in the back, worn brakes or a tire blows, you're going a bit too fast or are tired, slippy road, heavy winds or a big pothole...

all it takes is 2-3 factors to coincide.

Compared to a nice heavy TV pulling half what it's max rated for, which one would you rather your young only child riding in?

If you ask, what have children got to do with it? my answer is: exactly!
Tom&Shelly wrote:Thank you John,

While not exactly what I wanted to hear, it sounds like good advice, which is really what I'm looking for by posting here.

Towing long distances, we also want to feel comfortable with the rig. Guess there may be a larger tow vehicle in our future.

Tom
John61CT wrote:Or maybe worth going to more trouble reducing weight.

Think like a backpacker, maybe not every ounce, but make every pound count, most carry stuff they don't really need; be ruthless, aluminum, composites rather than steel, foam rather than wood, etc.

Or if nothing else just being aware you're pushing limits, ease off on the lead foot and set a more leisurely travel schedule, be conservative about weather conditions, check brakes and tire conditions more diligently, etc
Sorry but that's one of the most crazy things I have heard for a while. If you want to tell someone that their jeep with 2 people in it is overloaded you need a better reason than 'think of the children'. If something isn't fine to drive 1000 miles it isn't fine to drive 10 miles either. You shouldn't be driving a poorly maintained vehicle regardless of towing or not. A tire blowout when your not ready or failed brakes can result in an accident just as easily with a trailer as with an empty vehicle. Besides all that the 'safety' factor you are trying to create has already been overdone. The lawyers that give it a tow rating took the number the engineers said was safe, divided it 4 times, then rounded down to the nearest 500 pounds, then made it similar to other vehicles in its class. 

Tom and Shelly have you looked at what your vehicle is rated to tow in other countries? For example a yaris (cant remember the year) is rated to tow nothing in the USA, 700 pounds in Canada and 2000 pounds in Europe. A Honda crv is rated to tow 1500 pounds in the states, 3500 in Europe iirc. a 2001 Honda civic not rated to tow in north america but 1800 pounds is fine in Australia. Yes, a honda civic can safely and legally tow a heavier trailer over there than you are planning to here with your jeep. A 1500 pound trailer with brakes is nothing really. People used to tow that with 40hp VW beetles with 4 wheel drum brakes and no, all the children didn't die. 


Vehicles are not safe period, that's a lie everyone has been sold by the companies making them. Look at collision statistics. In my province anyway less than 1% of accidents resulted from any sort of failure of a vehicle-mechanical, tire or anything else. Most of those were tire failures. 99% of the time accidents are caused by people not paying attention or not driving to the road, weather or vehicle conditions because they are overconfident in how safe they are in their big oversized extra safe vehicle. There is no such thing as an collision caused by road conditions or weather. You shouldn't be driving more carefully with a trailer, just differently. Should pay just as much attention with no trailer as with. Vehicles are designed to keep you safeish in a 40mph crash with only a driver and passenger. They don't at 60mph and they for sure don't when you have extra weight like when your towing.

I could keep ranting for quite a while but i'm sure everyone else is annoyed at me by now.

Tom and Shelly-your jeep should have absolutely no issue towing what it is rated for all around the country if its maintained, has proper sized and good tires and your trailer has brakes and is properly loaded as you plan on doing. Your capabilities driving it would be the only thing you would have to question (i am not. once you get your trailer made and try towing it you just have to see how you think you would be able to handle emergency situations with the jeep. If your not sure I would suggest finding a road that is actually deserted and try swerving around starting at low speeds too see how you handle it and see how fast you can stop from 60mph or whatever your cruising speed is. How fast you can stop and how fast you can maneuver while maintaining complete control are things you need to know for any vehicle, towing or not.)

 A short wheelbase tall vehicle like a jeep just takes more skill to control than a shorter but longer vehicle. 

And yes, any weight you can remove (or not add) will make it easier to tow as long as its still balanced correctly


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Re: Weight and Balance

Postby linuxmanxxx » Thu Mar 29, 2018 1:07 am

I'll say it again, look at sandwich torsion box foam construction and save a ton of weight. Your TV would be way more than enough then and much less strain on it over time. I have a 4.6 V8 F-150 and a heavy tear is a big load on it when over 1k lbs and in hills and mountains. Sandwich walls over 3/4" foam when complete glued surface are less than a third of weight of solid 3/4" plywood and much stronger. Build light and you won't regret it.

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Re: Weight and Balance

Postby Tom&Shelly » Thu Mar 29, 2018 7:50 am

linuxmanxxx wrote:I'll say it again, look at sandwich torsion box foam construction and save a ton of weight. Your TV would be way more than enough then and much less strain on it over time. I have a 4.6 V8 F-150 and a heavy tear is a big load on it when over 1k lbs and in hills and mountains. Sandwich walls over 3/4" foam when complete glued surface are less than a third of weight of solid 3/4" plywood and much stronger. Build light and you won't regret it.

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Thank you Steve. Actually, I do plan on building with the sandwich torsion box foam construction. The weights I'm getting include a (very) rough estimate of that construction for floor and walls. As I refine the design, I'll draw the walls to scale and see how much they really weigh, but I expect they won't change by more than a few pounds there. Folks on here have talked about 60 lbs for their walls made of sandwich construction, and that's close to the numbers I'm getting.

A lot of my weight (544 lbs) is from the trailer frame. If I understood the engineering better, I might try and reduce that. As it is, I know we want something that will let us get off road, so I'm trying to make it rugged. I'm really relying on Andrew Gibben's tongue data and information from Steve Fredrick's manual and the "Trailer Frame Tutorial" from this site. About 2 feet between cross-members seems to be sort of standard. Using square tubing rather than channel seems better. I'm confident the frame will be rugged enough, which almost certainly means it's over-built. If I understood aluminum more, I might think about that. Anyway, we are getting a quote to have the frame built (I've never welded, and the first time for a road vehicle sounds like a bad idea), and if that comes in high, we may investigate the other options. (I think we're going to be burned by the recent politics over steel and aluminium imports.)

I agree with the philosophy of build light. It's implementing it in an intelligent manner, with my inexperience, that is the issue.

Tom
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Re: Weight and Balance

Postby linuxmanxxx » Thu Mar 29, 2018 7:59 am

Can you get 3/4" foam? If so then figure how to use 1x8 or 1x12 cedar or pine to do your outer frame and 1x2 for inner and your weight would go down even more. The 3/4"plywood cutout route is very heavy compared to this. I used 1x and Luan for my inner and outer skins and aluminum over it and built on heavy trailer same as you. Was storage under and 7x10 square cabin. Could have done it lighter but it came in 1100 with fridge and TV installed and 8k window unit.

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Re: Weight and Balance

Postby Tom&Shelly » Thu Mar 29, 2018 8:31 am

Hi John and Dan,

I appreciate the diversity of opinion. As a hard-headed engineer, I've participated in designs of spacecraft where similar issues (we call them "engineering trades") have to be made.

There are various appeals to safety (some more emotional than others ;) ); the one that registers with me is that we are (if I understand the numbers correctly) approaching the GCWR for our Jeep (at least as rated in the USA): 98% with the early weight estimates. That's just too close, and I'd like more margin. And yes, I recognize that number already has multiple safety factors included.

So, it's either make the camper lighter, or consider a heavier tow vehicle. I believe in the philosophy of making the camper lighter, but am inexperienced in this sort of design and still want to make it rugged enough to handle the various missions--er, camping trips, we have planned. We want to make it reasonably light, but also don't want to worry about going over our weight limit if, for example, my brother tries to give us a bushel of apples from his trees for the drive home. We want plenty of margin.

Another thing we are considering is how much fun this rig will be to drive. With a larger tow vehicle, the trailer won't be pushing us around as much.

A final factor in our thinking on buying a larger tow vehicle is our situation right now: I own a 2008 Jeep Wrangler with 210,000 miles, Shelly's has a 2009 Wrangler with 100,000 miles. I'm going to need a new vehicle before I die anyway, so maybe it's time for a trade up. Much as I love Wranglers for camping, it may be time for a hard headed decision.

Tom & Shelly
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Re: Weight and Balance

Postby dancam » Thu Mar 29, 2018 9:22 am

Tom&Shelly wrote:Hi John and Dan,

I appreciate the diversity of opinion. As a hard-headed engineer, I've participated in designs of spacecraft where similar issues (we call them "engineering trades") have to be made.

There are various appeals to safety (some more emotional than others ;) ); the one that registers with me is that we are (if I understand the numbers correctly) approaching the GCWR for our Jeep (at least as rated in the USA): 98% with the early weight estimates. That's just too close, and I'd like more margin. And yes, I recognize that number already has multiple safety factors included.

So, it's either make the camper lighter, or consider a heavier tow vehicle. I believe in the philosophy of making the camper lighter, but am inexperienced in this sort of design and still want to make it rugged enough to handle the various missions--er, camping trips, we have planned. We want to make it reasonably light, but also don't want to worry about going over our weight limit if, for example, my brother tries to give us a bushel of apples from his trees for the drive home. We want plenty of margin.

Another thing we are considering is how much fun this rig will be to drive. With a larger tow vehicle, the trailer won't be pushing us around as much.

A final factor in our thinking on buying a larger tow vehicle is our situation right now: I own a 2008 Jeep Wrangler with 210,000 miles, Shelly's has a 2009 Wrangler with 100,000 miles. I'm going to need a new vehicle before I die anyway, so maybe it's time for a trade up. Much as I love Wranglers for camping, it may be time for a hard headed decision.

Tom & Shelly
I just read through your first posts again and i dont think you will be able to keep your trailer to 1550 pounds loaded. I dont think your off on the estimates you gave, but i am building my first trailer now and there is so much you dont think of that adds weight. Does the weight of the frame include the axle and the 3 tires? 14in rims and tires arent light. Your camping 8-10 weeks at a time so you need propane right? Thats heavy. Water is the biggest thing for us. For a family of 4 to shower and drink/cook/clean a 3-4 day supply is 375-400 pounds. Just the hardware to hold my under trailer tank was pretty heavy. Then there is always things you want to take that you didnt plan on. Inflatable boat and motor, extra clothes and rain gear, firewood, spare parts for the TV and trailer (grease, tire plugs and pump and so on). I built a 5x11 lets say foamie and painted it inside and out. Iirc that was well over 150 pounds of paint. At 50% solids thats like 75 pounds. Glue, fasteners, wiring, breakaway battery, door hardware... all those little things add up.

Anyway, it sounds like you have had these jeeps for a while, are used to driving them and like them, so thats a big plus. To me i would rather make a camper fit my tow vehicle if i liked it since i drive it all year, but if your considering getting something bigger anyway that is likely less work that trying to make your camper light enough.

Good luck! :)

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Re: Weight and Balance

Postby dancam » Thu Mar 29, 2018 9:38 am

Oh, just another thing. How hard something is to pull has a lot to do with aerodynamics- how much frontal area of the trailer is larger than the tow vehicle. I believe that has more affect than weight to a large extent.
Then stopping or how much you get pushed around has a lot to do with how well your trailer brakes are set up. Make sure you have a large enough ground wire going to the trailer frame from the trailer battery and make sure you have at least 12awg positive wire to the brakes. The brake ground should be big as well. The distance from your brake controller to the brakes themselves is long and at 12volts, 25ft even with 12awg wire and perfect connections your loosing 0.5volts which obiously results in a lower maximum trailer braking power.
Once you have your axle download the user manual for it. It will have all the info about greasing, adjusting brakes, maintinance, replacement part numbers for brakes and bearings and so on. The difference in braking performance of a trailer with properly adjusted brakes to one where the brakes are adjusted too loose is huge.
https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.rockwellamerican.com/sites/default/files/catalog/Axle%2520Service%2520Manual.pdf&ved=2ahUKEwjcvuHc55HaAhUW5mMKHUOPBycQFjAAegQIBxAB&usg=AOvVaw3aYUx4PNxSwov1g2bhrEXr

Also make sure your getting radial tires, not bias ply.

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Re: Weight and Balance

Postby Tom&Shelly » Thu Mar 29, 2018 1:28 pm

Tom & Shelly[/quote]I just read through your first posts again and i dont think you will be able to keep your trailer to 1550 pounds loaded. I dont think your off on the estimates you gave, but i am building my first trailer now and there is so much you dont think of that adds weight. Does the weight of the frame include the axle and the 3 tires? 14in rims and tires arent light. Your camping 8-10 weeks at a time so you need propane right? Thats heavy. Water is the biggest thing for us. For a family of 4 to shower and drink/cook/clean a 3-4 day supply is 375-400 pounds. Just the hardware to hold my under trailer tank was pretty heavy. Then there is always things you want to take that you didnt plan on. Inflatable boat and motor, extra clothes and rain gear, firewood, spare parts for the TV and trailer (grease, tire plugs and pump and so on). I built a 5x11 lets say foamie and painted it inside and out. Iirc that was well over 150 pounds of paint. At 50% solids thats like 75 pounds. Glue, fasteners, wiring, breakaway battery, door hardware... all those little things add up.

Anyway, it sounds like you have had these jeeps for a while, are used to driving them and like them, so thats a big plus. To me i would rather make a camper fit my tow vehicle if i liked it since i drive it all year, but if your considering getting something bigger anyway that is likely less work that trying to make your camper light enough.

Good luck! :)

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Hi Dan,

Thank you! I did estimate the weight of the axle (75 lbs for a 3500 lb spring leaf kit from Amazon) and 3 tires/wheels (45 lbs apiece). I didn't estimate the fiber glass or paint/bedliner yet, and agree that's likely over 100 lbs. I baselined 5 gallons of water in the teardrop, figuring on keeping more, when necessary in the TV. But, that still counts against the GCWR so is another vote for getting a larger vehicle. When tent camping we use one of those small bottles of propane every three days or so, so we planned on keeping a few at a time and buying as we go. Not the cheapest way to do it for sure. Anyway, I agree, we were cutting the weight margins too close for the sort of camping we want to do.

Just got a quote from MCT in Albuquerque and it would cost $4250 for a custom made trailer. Yikes! that came in at least twice what I was looking for. Guess we need to look at other options there!

Tom
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