[masraum]

Originally Posted by Scott Douglas

If the rails are anchored to the roof at the ends, moving the bars to the furthest fore/aft positions will give them the least amount of leverage on the rails.
One thing to keep in mind is the aero loading from driving at speed.

If I were moving a bed (box spring/mattress set), I'd load the box spring on first and be sure to tie the mattress down to it at the leading edge to keep it from being bent up by the wind pressure.
I also wouldn't drive over 55 mph either, but that's just me not wanting to litter the highway with my stuff.

Right, when moving stuff like mattresses, plywood, etc..., I've always tended to hang them more forward and tried to angle them down a little bit, and then ensured that the front was strapped to try to keep wind from getting under it and bending it up.

What the missus wants to move is a queen sized box spring, and the drive would be 55 miles from the nearest store. We could probably avoid the interstate for 25 miles and use a state highway. I could maybe stick to a feeder/frontage road for more. But there's also a ton of construction so that might force us onto the highway.

Right, I've seen the results of folks that did a crap job of tying a mattress down. I've seen people driving with the front of the mattress standing straight up with the mattress bent at a 90º angle. I've seen mattresses on the side of the interstate. I've seen mattresses that looked like they'd been run over or dragged. And I've seen pics of cars on fire with a mattress wedged underneath or with what looks like mattress springs wrapped around a drive shaft.