Roof rack design preference: Longitudinal or lateral slats?

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nateh

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I'm going to be building my own roof rack and need to decide how to design it. I'm thinking of using almost all 80/20 extruded aluminum. Problem is, I've literally never owned a vehicle with a full roof rack like this so I don't know what I like or not. I really really like the look of the Frontrunner Slimline II rack and so my plan was to basically copy that but I've heard wind noise is a big deal. I want to ask all you experts on what your real-life experience has taught you. Any tips would be appreciated (with rationale!)
 

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I have a Pioneer Platform Rhino Rack with slats the long way on my trailer, and though mostly covered with a rooftop tent, I can't help but think the aerodynamics offer less resistance than slats going cross way. I have no real data to support either way, though. I've always thought it would be interesting to put this sort of thing through wind tunnel tests.

I also think, at least in my situation, that being able to slide along the length instead of side to side is advantageous, though with as many different types of container holders and attachment accessories available, it's not a contentious point.

The attachment accessories for these racks are pretty much interchangeable from one brand to another, at least from Pioneer to Front Runner, in my experience.
 

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Lindenwood

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Most of my uses point to lateral bars. Loading lumber or kayaks from the rear of the vehicle, once you get the long piece over the first crossbar, sliding it all the way to the front over the rest of the lateral bars is easy as long as you keep sufficient weight on the back end to keep the nose up. Similarly, loading from the side, once you get the item onto the roof, with the lateral bars it's easy to slide the piece to the other side of the vehicle to keep loading from the same side.

Wind resistance may indeed be reduced with longitudinal slats over lateral slats, but that can largely be recouped with something like a thin piece of plywod over the top if you intend to keep the rack empty for everyday driving. Alternatively, a wind fearing is a GREAT addition to mitigate wind noise for if / when you have boxes or other gear on the roof.

Overall, ease of construction is probably going to be the biggest factor, though.
 
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Mikderf

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I have the Pioneer Platform from Rhino Rack on both of my rigs which are longitudinal. I cant speak for wind resistance, but for strapping down cargo, I don't think it'll matter too much either way. Once in awhile, while loading it up, I'll think to myself that it may have been easier if the slats was lateral. But other times, I'm glad my slats are longitudinal. So that was just a long way of saying I don't think it matters. As for wind noise, you're gonna get it no matter what. Even the Longitudinal setup needs lateral cross beams for support. A fairing would be the best option for that if it works with your setup.
 
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nateh

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Good to hear that from a functional standpoint it doesn't really seem to matter. I'd love to hear if anyone has tried both? Logically it seems that longitudinal bars would naturally be less noisy.
 
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Alanymarce

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The one we took on our last "big trip" had both - a rectangular perimeter (double - one above the other for an enclosed rack) then a series of lateral support rails , then a 'cross hatch" of both lateral and longitudinal supports. The main structure is 25 mm tubing, and the "crosshatch" is about 5 mm bar.