Genuine roof bar speed limit BEWARE

[DXX]

The roof rack profile is a noise reduction measure nothing to do with down force, turbulence creates noise, ref to earlier diagram I posted showing turbulence.
Aircraft wings have a round leading edge to split the laminar flow, the distance over the top of an aircraft wing is longer than the distance over the bottom of the wing creating a velocity and pressure difference.

 

[Cherokee]

I’m probably past my extent of knowledge upon this now, but wings are designed for lift, roof bars are not. So it’s seems improbable that roof bars should be installed as ‘wings’ if lift is not desired?

 

[dubber36]

If you turn an aeroplane wing upside down, it will create downforce.

Rounded at the leading edge with a tapered tail is the most aerodynamic shape, so benefits reduced drag and wind noise.

 

[Skyliner33]

I’m probably past my extent of knowledge upon this now, but wings are designed for lift, roof bars are not. So it’s seems improbable that roof bars should be installed as ‘wings’ if lift is not desired?

Roof bars are symmetrical when looked at end on. Aeroplane wings and car wings are not. The airflow under and over a roof bar will be the same so will not produce a vertical force up or down. However pointy end first will produce turbulance behind the roof bar. So creating drag and wind noise.

Plane wings looke like this, the air has to travel further over the top, so it travels faster and produces less pressure.

 

[DXX]

Roof bars are symmetrical when looked at end on. Aeroplane wings and car wings are not

Ditto

 

[Skyliner33]

Ditto

?

 

[DXX]

Just pointing out that I agree, it might take Lewis Hamiltons view point to convince others though.

 

[zlea73]

I'm glad I followed this thread I'm installing the cross bars today and I was truly confused as I was pretty sure the trailing edge should have been the slimmest
That mark Right and left didn't make sense to me.
I had a Thule bar for my car and the pointy bit points backwards

 

[Pete C]

I suspect that it really doesn’t matter which way round you install them, as they are tiny compared to the van and the thing you attach to the bars !
Just do them up tight, and check they are tight after a bit of use.

Pete

 

[Andysmee]

Do these crossbars have a channel for T-bar accessories like bike carriers?

 

[Andysmee]

Do these crossbars have a channel for T-bar accessories like bike carriers?

Answer : No

 

[Cjscos]

Answer : No

No but...... I took the center rubber out and put some t bolts in...

 

[Andysmee]

No but...... I took the center rubber out and put some t bolts in...

How so?

 

[n10n]

How so?

Resurrection… Omtec bars do have a channel that can accomodate t-bolts (such as Thule) fine



Also fitted the cross bars as per manufacturer recommendation - pointy edge leading. The roof box is also installed pointy edge leading