'03 roof rack wind noise problem

[brider]

I just got a set of used (great shape) Volvo load bars for my '03 XC70. Put them on last night, forward one about 6" behind the rear edge of the sunroof, rear one maybe 36" behind the front, and heard a very annoying wind noise today from about 40 mph on up.


I'm guessing this is a common problem, fluid mechanics aren't any diffferent where I live than anywhere else in the world, so how do I eliminate this problem? Is it all in positioning? Do I need a little fairing up there?

[bouvier]

I've had a set of the wing shaped bars from the start and don't start getting sound until 65+ MPH under normal conditions. In a heavy cross wind I get much more.


Bouvier

[brider]

Wing shaped bars? Mine are rectangular in cross-section, like a clone of a Thule bar.

[Jack]

I have both wing and Thule style bars from Volvo. The wing shaped bars are MUCH less noisy. I tried the Thule branded bar adaptors and they were even worse, plus they could scratch the rails and were more expensive.

[jkochis]

Get a fairing...

http://www.thuleracks.com/thule/product.asp?dept_id=83&sku=872

Worked for me...

[bbbuzzy]

While a fairing should work well, I found that having an attachment on the rack reduces the whistling noise considerably. I have 58" bars with the Crossroads mounting to the rails. With a ski carrier or kayak saddles in place, the noise is greatly reduced. Gas mileage is still 24mpg on the highway (just tested last weekend with a fully loaded car running at 32psi all around). Mileage calculated by hand (miles driven divided by gas consumed). Can't trust the computer, it's way off.

Off topic: to the previous poster...love your cars! (same as mine)

[birddog]

I agree, get a fairing. Mine is located right behind the sunroof opening and there is virtually no noise, even with the bike and kayak carriers installed. Works like a charm. [thumbup]

[Art]

In the little time it takes to remove the load bars altogether, I personally find this to be the preferred method when it comes to eliminating wind noise. :)

Naturally, this method likely works better if you don't require full-time use of your rack accessories. ;)

[Castle]

In the little time it takes to remove the load bars altogether, I personally find this to be the preferred method when it comes to eliminating wind noise. :)

I, too, tend to remove the crossbars when not using them. If you are using a top box, it is really easy to leave the box attached to the bars and remove the entire assembly from the roof - just takes two people so as not to scratch the car.

While the aero/oval/tapered bars look cool and make less noise, they didn't fit all the existing Thule attachments already in my garage.

[barrysharp]

I've had the Volvo wing profile cross bars since my car was new - bought them at the Factory Delivery Center in Goteborg. They work great and there's really no decernable noise until maybe 45 mph and then goes away at around 50 mph. I have the rear cross bar located as far back as is possible. The leading cross bar is exactly 31" forward of the rear one. I did experiment some without anything attached to cross bars as this is the normal mode of use and found this positioning to minimise wind turbulence noise. I never remove the cross bars.

[brider]

That's what I'm going to do before I buy a fairing-experiment with bar positioning to locate the optimum (least noise) position. Should be fun!

[Lawrence Lee]

Hi,

Yes, try moving as far back (or rear) as possible for the cross bar, it does helps to reduce wind noise tremendously. I have fixed 'permanently' the corss bar and the bike carrier on my XC roof and never remove it even going above 180 km/h..... the wind noise is still bearable.

See attached pics.

Cheers!

[Cross Current]

I have the thule cross bars and often transport kayaks so I prefer to have the bars spaced apart. The noise was pretty bad but the fairing did the cure well enough that I leave the cross bars on year round. Good Luck.

[brider]

Lawrence Lee:

We have the same Ash Gold color (mine is a 2003), and the same bike carriers, too! I see yours are mounted "backwards", that is, the bikes face to the rear. Can I ask why you do that?

Also, is it necessary to strap the arms for the BigMouth jaws down when not in use? How do they keep from bouncing up and down?

brider

[Lawrence Lee]

Hi brider,

Actually there is no particular reason for mounting the bikes facing to the rear. This picture was taken sometime in 2004 and I was 'testing' the 'best' position for mounting the bike to reduce wind noise. I have come to my own conclusion that monting the bike facing backwards does help to further reduce some noise casued by the bike's handle bar if mounting is facing the front.

If you look at the first picture, I have recently changed the bike carrier and the cross bar to the latest 'aerodynamics' type from OEM Thule - Volvo. With this change, the wind noise is further 'subsided' and I am currently very happy with this set-up. Even if I reached the speed of 180km/h, the wind noise is still bearable as I fixed them permanently there.

As for the arms of those 'big-mouth' jaws, I used to strap them with velco strips to prevent them from 'bouncing' up & down when not in use.

Cheers!


Lawrence Lee:

We have the same Ash Gold color (mine is a 2003), and the same bike carriers, too! I see yours are mounted "backwards", that is, the bikes face to the rear. Can I ask why you do that?

Also, is it necessary to strap the arms for the BigMouth jaws down when not in use? How do they keep from bouncing up and down?

brider