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  1. #1
    Mountain Biking Newbie
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    For the rooftops...fairing or no fairing?

    What do you guys think....do you think the fairing helps with fuel economy?

    I have an old school fairing for my Thule roof rack (with 2 of the old 589 Velo-Vise trays) and I see that I get about a 3 mpg hit on economy (without bikes).

    Would you think that removing the old-style fairing would improve my fuel?

    What about using the newer fairings instead?

    BTW, it's mounted on an '06 Accord Sedan.
    2011 Specialized Epic Comp 26
    1994 Specialized Hard Rock FS

  2. #2
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    Aerodynamics are one of those areas of science that is not obvious in that what you think would be correct seldom is.

    If you where to round the front and make a nice smooth shape on a brick. It would be barely more aerodynamically efficient than a flat fronted brick. However, if you where then to reverse the brick the aerodynamic efficiency would improve dramatically!

    It is not how you part the air, but how it is brought back together that is important. It reduces drag. So, I doubt any fairing at the front would improve MPG at all, but it would make it look like it would to the untrained eye.

  3. #3
    Elitest thrill junkie
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    Quote Originally Posted by Kanza View Post
    Aerodynamics are one of those areas of science that is not obvious in that what you think would be correct seldom is.

    If you where to round the front and make a nice smooth shape on a brick. It would be barely more aerodynamically efficient than a flat fronted brick. However, if you where then to reverse the brick the aerodynamic efficiency would improve dramatically!

    It is not how you part the air, but how it is brought back together that is important. It reduces drag. So, I doubt any fairing at the front would improve MPG at all, but it would make it look like it would to the untrained eye.
    Agree, in fact a lot of little protrusions and extensions can reduce drag, vs a big "aero" fairing. It might be quieter, but anywhere that the air becomes "separated" from the surface creates a huge amount of drag. It could improve, or it could be worse. Would have to "wind tunnel" it to be sure.
    "It's only when you stand over it, you know, when you physically stand over the bike, that then you say 'hey, I don't have much stand over height', you know"-T. Ellsworth

    You're turning black metallic.

  4. #4
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    Quote Originally Posted by Kanza View Post
    Aerodynamics are one of those areas of science that is not obvious in that what you think would be correct seldom is.

    If you where to round the front and make a nice smooth shape on a brick. It would be barely more aerodynamically efficient than a flat fronted brick. However, if you where then to reverse the brick the aerodynamic efficiency would improve dramatically!

    It is not how you part the air, but how it is brought back together that is important. It reduces drag. So, I doubt any fairing at the front would improve MPG at all, but it would make it look like it would to the untrained eye.
    Makes me want to put a huge cone at the rear of my Element!

  5. #5
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    I was just thinking that the fairing would be worse for fuel economy than just the rack on there...figure only the crossbar and tray would impede air flow, but with the fairing, you have this large area that is trying to push air away.
    2011 Specialized Epic Comp 26
    1994 Specialized Hard Rock FS

  6. #6
    XC racer
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    Considering noise, not gas mileage, I've had mixed results with fairings. My first roof rack ever was a round bar Yakima and without a fairing it HOWLED at anything over 45mph. All of my racks since have been Thule square bars or OEM Euro aero bars and none of them have been too noisy without fairings. As stated by others, aerodynamics is not always easy to define. I leave the OEM roofrack with two RockyMount trays on my MINI all the time and still get 25-28mpg city/hwy. Add a couple of bikes and it can drop as low as 24 depending on speed but still very acceptable to me. It might eek out 1-2 more mpg by taking it off when not in use, but it's not worth the hassle to me.

  7. #7
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    For me, my sanity while driving wins out over what little benefits may or may not be had with a fairing. Without a fairing, my roof rack whistled like crazy. I got a nice, wide fairing on there and the rack is as quiet now than my car without a roof rack.

  8. #8
    ballbuster
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    I wanna try one out to see if I can tolerate the noise at freeway speeds with an open sunroof, but I just don't want to drop real cash on one.

    I have my eyes peeled on craigslist.

  9. #9
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    i've had them stolen twice. not worth the money to replace again and again.

  10. #10
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    i will say that i switched from yakima copperheads to thule uprights and the noise is so much less now.

  11. #11
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    The fairing is just to cut down on noise. Take the bike trays off when you are not using them to help with gas mileage.

  12. #12
    ballbuster
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    Heh...

    Quote Originally Posted by pimpbot View Post
    I wanna try one out to see if I can tolerate the noise at freeway speeds with an open sunroof, but I just don't want to drop real cash on one.

    I have my eyes peeled on craigslist.
    I found one at a swap meet. I blew another $15-20 for various hardware to make it work with my rack, and some clear film tape to keep it from scratching my wife's car roof.

    I got it on, got it fit perfectly, got it up to speed on the freeway and...

    BBBBZZZZZBBBZZZBBBBZZZBZBBZBZBZZZZBZBZ!

    The thing buzzes like crazy. I took it off. I did somewhere wrong in there somehow. I need to figure out why it's resonating and buzzing. Meh....

    The car is much quieter with no roof rack, with or without a fairing. I don't really need the roof rack on this car anyway.

  13. #13
    ballbuster
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    Like this?

    Quote Originally Posted by the-one1 View Post
    Makes me want to put a huge cone at the rear of my Element!

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