Roof Rack -Reducing Drag

[aerohead]

If you are going to be near water,lose the roof rack,get a swing-away spare tire mount for over the hatch.Buy a entry-level kayak and open it up at the seat location.Load all your gear into a kayak,and mount that (upside-down) to a smaller roof rack system close to the roof.The kayak will have virtually no drag,it will protect your gear from the worst weather,and you'll have the use of the kayak( by temporarily refitting the seat).Your fuel savings will easily cover the cost of the kayak.If you're clever,you'll be able to fit everything creatively inside the boat,and with help from your travel mates,it won't be any trouble to load and secure the boat.

[Nigel]

Rhino Rack - Roof top Luggage Boxes

These are available.

[MetroMPG]

A kayak container? Phil, you get full points for a creative and elegant solution.

[winkosmosis]

A kayak might not be that good for drag because the air going up from the windshield would hit it and be trapped. Maybe it doesn't matter since they're narrow and curved on top (the side facing down)

[aerohead]

Originally Posted by winkosmosis

A kayak might not be that good for drag because the air going up from the windshield would hit it and be trapped. Maybe it doesn't matter since they're narrow and curved on top (the side facing down)

winkosmosis,no doubt,the boat will cause some interference over the roof.I do believe such a "roof rack" would however offer the minimum loss do to ,as you've mentioned,the narrow profile with very small frontal area,and drag coefficient on the order of Cd0.06.----------- The majority of the hull should see no separated flow for the entire length.------ Should the kayak be mounted on an inverted aerodynamic pylon as bombs and drop-tanks and bellytanks are done,there would be virtually no drag to speak of.No separation anyhow.---------- Some of my neighbors report that they lose "nothing" when they transport canoe and kayak on their roof.Some have actually claimed "gains."--------- I'm polite enough not to challenge their claims,and one day will test for myself,as I have both a canoe and kayak,but they usually ride inside the bed of the truck.

[basjoos]

I used to use my folding kayak as a luggage carrier when traveling to and from college in the 70's. Imagine. A 68 VW bug crammed to the gills with stuff inside, with a loaded kayak on top, skies slanted forward on the ski rack over the rear engine lid, and a bike on a rear bumper-mounted bike rack. Still got 28mpg at 60mph even carrying that load.

[mikel09]

Avoid roof racks. Tests by Edmonds and Consumer Reports on a Thule roof box and a roof rack loaded with gear documented significant aerodynamic drag. The impact was 17-25% depending on car, speed type of carrier.

Another approach is to load all heavy gear inside and soft gear in a lift gate mounted carrier called AeroPACK. It eliminates the ~20% mpg penalty of roof mounted carriers. We find it is easy to load on a lift gate, folds up small, and does not block the back access.

[brucey]

Wouldnt the aeropack completely eliminate the rear view though? I'd much rather have trouble getting into the hatch then not be able to see behind me. Devil I know.

[mikel09]

The pack is adjustable, so we have it sit low on the lift gate. You can see out the back just fine. When traveling we typically load the van interior very high. This allows us to move gear outside into the pack, giving us more passenger room and visibiliy.

Cheers

[BamZipPow]

The AeroPACK reminds me of a parachute pack. I wonder how many people would stop following closely you if it had a pattern of a drag chute cover on it.