Roof Rack wind deflectors

[Rock Trol]

Hi everyone,

I have a question regarding wind deflectors on roof racks. Do they stop wind noise? I currently have a large Rhino steel mesh platform (2100mm x 1100mm) on 5 heavy duty bars. When it is empty and the car is doing over 90kph it can get quite noisy, especially if there is a cross wind.

I am not sure if the noise is coming from the mesh or the bars. I am planning on blocking the ends of the bars with foam to stop any wind noise reverberating in the hollow tubes.
Does anyone have a similar roof rack system and do you have the same noise problem?

[the evil twin]

If you have open tubes then that is the usual source of any wind noise.
Usually sounds somewhat like that noise you get blowing across the mouth of a bottle
Block them up with plugs or whatever and try it.
Sometimes the chair leg thingies from Bunnings are a perfect fit

Wind deflectors don't do much in the way of noise suppression most of the time but it depends on the rack

[Rock Trol]

Thanks E.T. It is that "noise you get blowing across the mouth of a bottle" that I can hear. I recently added 2 more bars up there so the noise has now gotten quite loud.
Sounds a bit like those Vuvuzela things that they had in South Africa during the World Cup.

If the wind deflector is not for noise, what is the purpose?

[MudRunnerTD]

Thanks E.T. It is that "noise you get blowing across the mouth of a bottle" that I can hear. I recently added 2 more bars up there so the noise has now gotten quite loud.
Sounds a bit like those Vuvuzela things that they had in South Africa during the World Cup.

If the wind deflector is not for noise, what is the purpose?

aerodynamics to reduce wind drag and direct the wind over your roof load thus reducing the impact on your fuel economy.

Thats why you see big ones on the roof of B Doubles, otherwise they are driving into a wall of air the whole time.

[the evil twin]

Thanks E.T. It is that "noise you get blowing across the mouth of a bottle" that I can hear. I recently added 2 more bars up there so the noise has now gotten quite loud.
Sounds a bit like those Vuvuzela things that they had in South Africa during the World Cup.

If the wind deflector is not for noise, what is the purpose?

If that is the case I reckon that most/all of the noise will be resonance from air flow across the open tubes.

Wind deflectors are there to reduce drag or purely cosmetic or a bit of both depending who you want to believe and where the rack is mounted.

[threedogs]

Square bars make more noise than the Aero stlye bars that Rhino make.
The older style racks made from 20x20 rhs had mesh floors to stop them making a noise
I did run 4 Rhino aero bars with no noise as they have a rubber insert that fits inside the bar.
Id be looking at how tight you can get the lot

[FNQGU]

Totally agree TD. My previous work trucks both had roof racks - one was a box section type and the other was a tubular type. The difference in noise was quite remarkable, not to mention the tubular type was far better for roping down loads.

[Rock Trol]

Thanks guys,

I'll be going to Clark rubber when I get the chance to see what they have. There should be something I can shape or compress to fit into the cavity. Why Rhino Rack has never offered sealed end caps I do not know. I remember seeing some yellow caps on eBay a couple of years ago that were made to fit over the heavy duty bars and seal the ends. I just did a search and could not find them so I suppose they stopped making them.

[Clunk]

Thanks guys,

I'll be going to Clark rubber when I get the chance to see what they have. There should be something I can shape or compress to fit into the cavity. Why Rhino Rack has never offered sealed end caps I do not know. I remember seeing some yellow caps on eBay a couple of years ago that were made to fit over the heavy duty bars and seal the ends. I just did a search and could not find them so I suppose they stopped making them.

I tend to find that the missus jabbering away drowns out any noise from the roof rack..... Haven’t decided which is worse, so usually just turn the radio up louder ;):D

I've got 3 heavy duty bars on mine with the alloy tray/cage thingy on top and to be honest haven't really noticed the noise with this setup.

[Rock Trol]

How far forward are the bars on your truck? My platform is 2.1 long so one bar is directly over my head and another not too far behind. This is where most of the noise coms from.
Maybe the air flow over the top of the windscreen is being directed into the bars. That's why I was asking about the wind deflectors as they may help direct the flow of air above the bars. Rhino do one for $119 and if it works in reducing noise and drag it would be worth it. If it's just for 'wank' factor I could live without it.

[threedogs]

Ideally you would position the racks over the pillars to support the weight better.
From memory the square style had a piece of flat welded to them to stop the noise.
I think the noise is mainly high pressure /low pressure, anything that disturbs the air
or helps deflect it has to be good I suppose, see what Clarke rubber have on offer.

[Clunk]

How far forward are the bars on your truck? My platform is 2.1 long so one bar is directly over my head and another not too far behind. This is where most of the noise coms from.
Maybe the air flow over the top of the windscreen is being directed into the bars. That's why I was asking about the wind deflectors as they may help direct the flow of air above the bars. Rhino do one for $119 and if it works in reducing noise and drag it would be worth it. If it's just for 'wank' factor I could live without it.

First bar just above the B pillar, so above my head, 2nd is a bit forward of the C pillar, the 3rd is between C & D pillars but closer to D than C

[Rock Trol]

I went to Clark Rubber on the weekend and bought some rubber that fits in the end holes of the Rhino heavy Duty bars and blocked all the holes. Unfortunately this did not work. Drove it on the highway tonight and the noise was still there. Drowns out the engine and tyre noise. Very noticeable.

Still not sure of a wind deflector will work or if its worth trying. Might just have to remove the whole thing.

[Clunk]

Do your bars have rubber strips that run through the whole length of the bars? How wide are the bars? Are the legs, 110mm or 150mm. Just trying to look at all variables.

I don't have rubber strips, my bars are 1500 wide (I think) and legs are the shorter 110mm ones, so bars sit farely close to the roof.

Does this make a difference to wind noise? I've got no idea but all I can say is, mine doesn't drown out engine or road noise.

Maybe it's the mesh platform as I use the alloy tray, which is 1800x1200

[Rock Trol]

I do use the rubber strips in the heavy duty roof bars. The legs are 110mm and I cut the bars to 1300mm in length so they don't stick out past the legs very much.
A couple of changes I made recently was to move the rack slightly forward as the end used to stick out past the rear doors and I added two more bars (total of 5) as I already had them. The rack has always been noisy when there are strong cross winds but I think it is noisier now.

Removing it and the bars is an option but I find it fiddley work to remove the legs with little bolts and rubbers and the cylindrical bits that fall out of the legs etc. If I take it off its likely to stay off the car until a really big trip where I can't take the camper comes along. Could be years. I do find it handy though to through things like max tracks or firewood etc on top when camping so my preference would be to keep it on if it wasn't so noisy.

Another option would be to sell it and maybe look at something like the Pioneer platform which is alloy and has planks instead of mesh. I am pretty certain now that it is the mesh causing most of the noise.

[sooty_10]

I have 3 heavy duty rhino bars on my patrol and didn't even notice a change in noise when I installed them. I would think it would most likely be your cage/mesh causing your issues.

[Rock Trol]

I'll take the mesh platform off on the weekend and see how the bars go on their own. To remove and add the platform is not too big a job.

[threedogs]

Can you put a picture of your bars here, so we can better understand your plight

[Clunk]

Can you put a picture of your bars here, so we can better understand your plight

It's five heavy duty bars with a steel mesh platform, what's hard to understand with that setup?

[threedogs]

if you can see how its set up you might just might see where or why its noisey

[Winnie]

I am pretty certain now that it is the mesh causing most of the noise.

My rack is covered with mesh and does not make any noise.

[threedogs]

@ Winnie is yours a basket on a few rhino racks ??

[Winnie]

No mine is an all in one cage, ARB style. A mesh floor is a mesh floor.

[threedogs]

Maybe you could get your local sheetmetal guy to bend a piece of 1/8th flat bent at 45 degrees
and somehow bolt it under the cage and on top of the first bar, maybe just enough to disturb the air
and make for a quieter drive,
Could use gal but treat any cut edges

[Clunk]

I reckon the noise is from the mesh itself vibrating and not wind noise through the bars themselves

[threedogs]

If thats the case then cable tie some clear perspex to the front of the basket

[gq_simon]

Been reading this forum for ages, I know I should do an intro bit first but this is the first thread that I might be able to help out with.

I took the roof rack of the gq to paint it a while ago and when I put it back on the wind noise was so loud it hurt (before I put it on it was just noticeable). When I put it on it was about 10cm further forward than before, when I moved out back it was fine again.

Hope it helps, Simon

[Clunk]

Hey Rock Trol, just ti make sure that every one is on right page, this is what I think you have

http://www.nissanpatrol.com.au/forums/images/imported/2015/02/41.jpg

which is attached to your bars by these (or similar)
http://www.nissanpatrol.com.au/forums/images/imported/2015/02/42.jpg

Now I'm far from an expert in matters such as these but I don't think a wind deflector would make a difference.

[Parksy]

I found cable tying the mesh to the tubes helped a lot in my case. The mesh was welded, but not in all spots, so the cable ties helped. I had some large cable ties to do this.

[Rock Trol]

55425
Thanks guys. I actually have moved the platform forward about 10 cm as well when I added the 2 extra bars. I think that gq_simon is on to something.
And Clunk you are correct, it is the type of platform in your picture.
Do you think having 5 bars would affect the harmonics?


55419
55421

Maybe I should move the front bar back behind the drivers door or over B pillar and move the whole rack until it over hangs the rear (used to stick out the back previously).

[Clunk]

No idea about harmonics mate but I reckon 5 bars might be a bit over kill, probably only need 4 max. As you've said, move the first bar above the B post, keep the last one where it is, and spread the others. Shouldn't have to move the platform back too far at all really. May just move the U-clamps in slightly along the bars first, so they're not fixed right at the edge of the platform, that way the mesh part is less likely to vibrate against the bar.

Guess it's all trial and error to see what does and doesn't work

[Rock Trol]

That's a good suggestion about moving the clamps inwards. I will also move the platform back.

Another suggestion made by a mate at work was to fix a rubber ute mat over the top of the mesh. The only problem I see is that it will cover the mesh so its harder to put the straps through. A mat with larger holes would still break up the air flow and might help.

[Clunk]

That's a good suggestion about moving the clamps inwards. I will also move the platform back.

Another suggestion made by a mate at work was to fix a rubber ute mat over the top of the mesh. The only problem I see is that it will cover the mesh so its harder to put the straps through. A mat with larger holes would still break up the air flow and might help.

Or maybe the mat might flap a bit in the turbulence

[Rock Trol]

My mate has a rubber ute mat on his ARB rack with mesh and it does not move as it is quite heavy. There is a link to the stuff below. He says his roof rack is very quiet and he drives a petrol Prado so no diesel roar to block out the any noise from above.

http://www.clarkrubber.com.au/ute-matting.html

[outback]

Possible option.

Move front bar as far forward as possible.
Move second bar to pilot between drivers door and rear door
Move third bar to pillar between rear dood and back section.

Sorry keep getting pillar labels, A,B,C,D etc confused.

Also try cable ties to pull mesh down hard onto bars.

[Rock Trol]

Well, I have just sold the Rhino platform and 3 of the bars to a young guy who has just bought a Patrol. I had a think about how much use I would get out of the thing and decided just to keep 2 of the bars in case I need to pick something up from the hardware store or if I need to carry the Maxtrax and or the garden shovel. If I ever need a full length platform again I will just buy the Pioneer platform and use the 4 legs off the bars and buy another 2.

The interesting thing is that he had just bought his Patrol from his father in law who basically used it to tow a van around Australia once and to tow a boat occasionally. It's a 2003 ST 4800 with only 35000 km on the clock. This car was in show room condition inside and out.

[Clunk]

Well, I have just sold the Rhino platform and 3 of the bars to a young guy who has just bought a Patrol. I had a think about how much use I would get out of the thing and decided just to keep 2 of the bars in case I need to pick something up from the hardware store or if I need to carry the Maxtrax and or the garden shovel. If I ever need a full length platform again I will just buy the Pioneer platform and use the 4 legs off the bars and buy another 2.

The interesting thing is that he had just bought his Patrol from his father in law who basically used it to tow a van around Australia once and to tow a boat occasionally. It's a 2003 ST 4800 with only 35000 km on the clock. This car was in show room condition inside and out.


well I hope you pointed him to this thread in-case of any noise!!!!! lol

[Rock Trol]

well I hope you pointed him to this thread in-case of any noise!!!!! lol

What's the old saying? Caveat emptor (Buyer beware).

Seriously though, when we installed it on his car I moved the platform further back (as was originally installed on mine) so it won't be too bad (not like it was with the 5 bars on). I explained that the further forward it is, the noisier it gets.
The only reason I bought something that long (2100mm) was for my Oztent which I have since sold. The platform was mostly empty when camping. Now with a camper I use a 3 man popup tent if I need to rough it. Hope I get better fuel economy on the highway now. Was 12.8 km/100 when not towing.

[threedogs]

The interesting thing is that he had just bought his Patrol from his father in law who basically used it to tow a van around Australia once and to tow a boat occasionally. It's a 2003 ST 4800 with only 35000 km on the clock. This car was in show room condition inside and out.[/QUOTE]

Not a petrol guy but thats a great buy in anyones books