My rig is an '07 FJ Cruiser. I'm in the process of "building" a trailer. I have a 30 gal water tank I'm planning to mount directly in the front, outside of the bed, on the tongue of the trailer. Along with this water tank, there will be a tool box (recovery gear, tools) and my electrical box that will consist of an Odyssey pc2150 agm, AIMs 2500 watt inverter, mppt controller, wiring. I believe the max tongue weight of the FJ is 500lbs. I should be right under it after it's all done. Anything I need to worry about? It's a 4x6 trailer on 3500lbs Tembren axle-less suspension.
Mounting water tank on tongue?
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Depends on where the axle is located compared to where the water tank sets, think fulcrum of a lever, and how much weight you are putting behind the axle. It’s been a while since I looked up trailer loading specs, so I don’t remember the exact formula. I know that I center my heavy weight over the axle of my trailer and then load the trailer to be slightly tongue heavy.
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What first comes to mind, @fugi, with up to 250lbs of water that far forward and on the tongue, is that your trailer's tongue weight, overall weight balance, and center of gravity will change as water gets used.
From experience, I can tell you that matters. It will make a difference in how your trailer tows and reacts on both highway and trail. You won't always be able to fill the tank before heading out, either, to keep it the same, especially once out here on the road and adventuring.
Another thing to consider is the shape of the tank and how much water can rush to one side or the other if off-camber. It can really, and suddenly, affect the center of gravity when 150lbs or more of water gets shifted to just one side.
The 22 gal tank on my trailer (made by a company whose main biz is military trailers for govt's around the world) is underneath, over the axle, armored. It also has an interior baffle to prevent the full sloshing to one side if off-camber.
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I'd want it closer to the axle. 500# would be fine for a 5000# trailer but it is all about balance, tongue weight should be 10-15% of the trailer weight.
The only other option would be to mount it underneath the trailer which would mean I'll have to get a new water tank because I don't want to lose the storeage space of the bed at all. I'll have to Google to see what's available as far as water tank options goes...
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The place I used to look at when planning for both vans and trailers is plastic-marts RV Water Tank page . They have several that are only 6-8" in height, for under mounts.
Other than that, here's a thread on EP about water tanks that may help steer you towards something: Flat Poly Water Tank for Underside Of Trailer
and here's a page of under-trailer water tank images that might lead you somewhere.
Good luck - let us know what you end up using. Could be helpful info for someone else here.
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Roaddude - On the Road In North America - ROADDUDE
Roaddude - Traveling Photographer/Writer/Artist On the Road In North America. Gear, reviews, people, places, and culture.
roaddude.com
Advocate III
- 5,584
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- Michael
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- Rose
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