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Truck Camper Forum _ General Discussion _ Fit a short bed camper on a long bed?

Posted by: Sloppy Jan 9 2012, 05:27 PM

I'd like to fit a Lance 825, shortbed camper on my Longbed F350. I've heard that I need a "spacer" to fit between the cab and camper. I've looked around the internet but haven't found any. Can you steer me in the right direction or is this just not a good idea... thanks in advance.

Posted by: Spanky Jan 9 2012, 07:41 PM

How long is the 825? If it's 8 ft then it should fit without any spacer. I have never heard of a spacer.

Posted by: Sloppy Jan 9 2012, 08:02 PM

Lance 825 interior floor length, according o the brochure, is 8'6" F350 Longbed is 8'. Thx.

Sloppy.

Posted by: aqualung Jan 10 2012, 12:41 PM

The 825 adds storage compartments on each side at the rear. These compartments prevent the camper from going all the way in on a long bed truck - they would hit the tail lights before the camper bumpers touch the front of the box.

A spacer can be anything that goes between the bumpers and the front of the box. Its only there to prevent the camper from sliding forward. 2x4s would work just fine or you could try to extend the bumpers by putting some wood in behind them.

One concern with putting a shortbox camper on a long box truck is where the center of gravity lines up once its on the truck. You want the COG of the camper to be in front of the rear axles. Using a short box camper and putting a spacer in may push the COG behind the rear axles which makes the truck less stable. You may get lucky and the COG will line up ok but if it were me I would look at long box campers for your truck. Failing that, take really carefull measurements of the 825 to see where the COG actually lines up.

COG of the 825 is 45" from where it contacts the tail lights forward. So if the measurement from your tail lights to the rear axle is more than 45" then the COG will be behind the rear axle.

The down side of long box campers is that they don't get the handy storage compartments on each side.

Posted by: Sloppy Jan 10 2012, 11:04 PM

Ah, great point about the storage compartments and COG. I guess I'll have to take some measurements. Thanks.

Posted by: Electric Don Jan 12 2012, 10:51 PM

My Lance 805 short bed camper was installed on a truck with an 8 foot box before I bought it. The camper has removeable storage compartments which allow it to be installed in an 8 foot box without any problem, without having to install spacers so it doesn't affect the centre of gravity. Prior to putting it on my short bed truck we just re-installed the storage compartments. Perhaps the 825 has a similar system.

Posted by: kosraedan Mar 20 2013, 11:08 PM

The issue of CG is misleading. The real issue is one of moment...the distance from the CG to the rear axle times weight. Thus 2000 pounds at 6 inches has the same effect on the weight on front as 200 pounds at 5 feet. Thus, if 200 pound tongue weight of a bumper pull has no effect on steering, neither will a CG of a camper six inches behind the rear axle. Your measurements will vary, but the principle remains the same. A small shift in CG is very unlikely to destablize the vehicle.

Posted by: kosraedan Mar 21 2013, 07:05 AM

QUOTE(kosraedan @ Mar 20 2013, 11:08 PM)
The issue of CG is misleading.  The real issue is one of moment...the distance from the CG to the rear axle times weight.  Thus 2000 pounds at 6 inches has the same effect on the weight on front as 200 pounds at 5 feet.  Thus, if 200 pound tongue weight of a bumper pull has no effect on steering, neither will a CG of a camper six inches behind the rear axle.  Your measurements will vary, but the principle remains the same.  A small shift in CG is very unlikely to destablize the vehicle.
*




To update, CG is even less a factor than I described. CG is a factor when the turning moment is centered around a perpendicular or lateral line...an airplane wing for example. None of the weight is born elsewhere. With a camper, the weight is borne reasonably equally over the bed of the truck. Wiht a rear CG, perhaps 10% is borne aft of the rear axle. Presuming equal psi on the truck bed (probably pessimistic because the cabover section is supported by the front half), only the portion further away from the rear axle than the front of the bed is any actor. This probably means only the weight on the tailgate is a consideration.
I have a farm, and frequently put 1000 pounds on my tailgate with no problems. I cannot see how CG is even a small factor in stability.
What makes the front "light" is simply depressing the rear springs. That causes weight to be taken off the front. That is why equalizer hitches work with trailers. I also have a trailer with 700 lb. tongue weight.
Use airbags if necessary, keep the weight at something yoiur truck can haul, and you will be fine. CG is a factor only if it falls over an unsupported part of the truck. Unless you are hauling a crane that will never happen.

By the way, working trucks frequently haul well above the rated load. Those ratings have a significant safety factor built in. One seldom hears of structural failure....however, you might be that one.

By the way, I have a degree in engineering. This isn't all guesswork .

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