[billmeek]

A long while back I ran across multiple web pages that said some burgmans have working air vents. There is a sliding button in the cover above what I think is the speedo. Move it toward the front of the bike and the vent is closed. I know my 2003 Burgman 400 doesn't have a working vent. Maybe the vents only worked on bikes in some markets or specific year models.

Here's a pic of the control:

Anyone have the air vents that work?

 

[billmeek]

Did a little more research and found all the sites that list the adjustable vents are UK sites. One of them lists the vents on the AN400K4! :shock:

 

[Normsthename]

My Burgman 400 had the Vent, but it was about as much use as an handbrake on a canoe :lol:

Andy

 

[Randy]

I'm not worried about the vent, I am still looking for the shaft drive :lol:

 

[billmeek]

What I was wondering is if the vents change the aor bubble created by the windshield. Any effect on backpressure, etc

 

[pauljo]

What I was wondering is if the vents change the air bubble created by the windshield. Any effect on backpressure, etc

Due to the design of the Goldwing vent, which this one emulates, I'd say that the effect on the air bubble would be negligible. This vent is designed to direct cooling air to your body. A Goldwing test in the current Rider magazine says that it does that quite well. But its size in comparison to the overall size of an XXL windscreen is not big enough to seriously alter the dynamics of the air bubble formed by the windscreen. This is theory - I haven't tested one - so we still need feedback from folks who have.

Rifle makes windscreens for many bikes - unfortunately not for the Burgmans. I had one on my Concours. They put an airscoop at the base of the windscreen that throws a strong flow of air up the inside of the windscreen (not at the rider). That does affect the bubble and it helps eliminate backpressure. Different vent designs for different purposes.

 

[Randy]

I am sitting here feeling dumb (of course with me that's easy ) , I have been riding bikes on and off for over 45 years and I am just now realizing I don't know what is meant by the term windshield backpressure ,
so will someone please define it for me, and what it feels like.
I must know what it is, but I think my brain's still asleep

 

[NormanB]

I am sitting here feeling dumb (of course with me that's easy ) , I have been riding bikes on and off for over 45 years and I am just now realizing I don't know what is meant by the term windshield backpressure ,
so will someone please define it for me, and what it feels like.
I must know what it is, but I think my brain's still asleep

Its all about aerodynamics.

As you move forward you displace air that moves over the screen and a local low pressure area is created behind it. At some point these two streams of air just want to get back together and the air zooming over the top collapses into the low pressure area. If your head is in the 'mixing point' - it gets buffeted. You can change things by altering the height and/ or rake of the screen, lower your head or by putting an aerodynamic structure behind the riders body to delay mixing.

The link posted the other day, showing the 'Voyager' Feet Forward motorbike is an example of using this latter principle to good effect.

Any good?

 

[Randy]

Thanks NormanB

I understand your definition and have always just thought of it as buffeting without giving it a proper name.
So if I understand what your saying then a vent should have some small effect on it..