I'm trying to keep the airflow from dropping down to hit the front of the cargo carrier. I guess I could telescope the tongue, and check my mileage at different lengths. My Prius gives cumulative MPG readings. The trunk lip is 44 inches from the ground, and the front of the carrier is 39 inches from the ground. The carrier is 67 inches long, and I plan to stretch the trailer box by 19 inches.You may not have noticed, but the carrier is mounted backwards from the way it would be on the top of a car, to give it a rearward taper. I appreciate your learned advice.
Cargo Trailer Aerodynamics
- Thread starter ITTOG
- Start date
Kent Wold
New member
Just remember that the shorter the distance between the rear wheels of the TV and wheels of the trailer makes for a faster moment of turn when backing up the trailer.
Longer distance is slower moment of turn and an easier backing experience.
Also don't get to much weight up front or the trailer becomes very unstable when towing. It's a balancing act and there are many variables to consider.
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Longer distance is slower moment of turn and an easier backing experience.
Also don't get to much weight up front or the trailer becomes very unstable when towing. It's a balancing act and there are many variables to consider.
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Thank you. I plan to park away from stores so I can pull out. (want to position the carrier as close as possible to the TV without crunching on full lock forward turns) There will be much experimenting to get ball weight correct, and trailer balance. Since I'm putting a 67" long carrier on a 48" long trailer, there will be some encroachment inn the tongue area, and I'm wondering if I should regain some of that lost distance with an 11 3/4 extended ball mount, or should I keep the ball close to the car, and pull the tongue further forward? What are the differences in dynamics betwen a long ball mount to a short ball mount. I can experiment with tongue attachment, stretching the frame, and axle location (9 1/2" forward), but I don't want to buy two ball mounts.
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Air in from the bottom and sides has a high impact on drag as well. I’m guessing (just guessing) that you will lose a high % of the overall mileage from that car based on its design specifically intended to reduce drag. Maybe 20% loss? Look at the bottom of the car and how smooth it is, now think about the turbulence on the bottom of the trailer.
Kent Wold
New member
My concern is that the trailer looks tongue heavy..doubt it can be posted here easily but I've seen a physics explanation on a Facebook video tht clearly showed the difference between a balanced load a load to heavy in the rear etc..you can quickly lose control of the vehicle or at least have an uncomfortable drive if the loading isn't correct..
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I’m confused as to why the overhang is “undesirable”? Those boxes are generally strong enough to overhang, they only mount on a couple of little crossbars on top of a car. It seems like you are taking on a bunch of work to achieve little or nothing. Just bolt the box to the trailer, extend the tongue to prevent contact at full turn and go. Learning how to load the weight will achieve the balance you need. How much will this thing weigh?
If the picture is true to your desired configuration, that overhang won’t trap any more wind than extending the frame by the same amount.
I’m often guilty of chasing projects far down the road of diminishing returns in a quest to achieve what I believe is “right”... trust me ... this is what the beginning of that trip looks like.
You could make an extremely simple “backbone” type of trailer with a single cross member triangulated to hold the axle, maybe even a single transverse leaf spring if you wanted to get extremely low profile. A second cross member holds the cargo box, and you’re done. At 300 lbs, you have nothing significant in it.
Think of a light rowboat or jet ski trailer. Heck, maybe even a commercial kayak or canoe trailer shortened.
I’m often guilty of chasing projects far down the road of diminishing returns in a quest to achieve what I believe is “right”... trust me ... this is what the beginning of that trip looks like.
You could make an extremely simple “backbone” type of trailer with a single cross member triangulated to hold the axle, maybe even a single transverse leaf spring if you wanted to get extremely low profile. A second cross member holds the cargo box, and you’re done. At 300 lbs, you have nothing significant in it.
Think of a light rowboat or jet ski trailer. Heck, maybe even a commercial kayak or canoe trailer shortened.
Thank you. I suspect leverage might be a problem. A foot out might double the receiver weight that half a foot out would feel. I've been doing some drawing, and I think I can extend the tongue by the 19 inches my carrier would overhang the frame, and keep the 31 inches of free tongue length. I'll post the series when I get to the computer they are on.
Yes, I overbuild. I once built a bunk bed for my kids, and I used 4 by 4s. Engineers are taught to put in a minimal amount of overbuilding (I think it's 15%), but I usually take that to 200%.
I believe I have come up with a "sandwich" solution that will allow me to extend the tongue safely, and turn the whole trailer (minus the springs, axle, and tires) into a four inch thick flat plane. I'll post it when I am near the other computer.
