This RS screen cutting-down business?

[Armaguidon13]

It's a good thing Sunbeem, I was always leaving my indicator on as the oe telltale was out of my peripheral vision.
So I rarely indicated unless people really needed to know where I was going.
Now, I can indicate to my hearts content as the led is very much in view.
I used two diodes, one led, and 'thin' multi strand insulated copper wire.
It hasn't stopped working yet.

Clever idea !

[Sunbeem]

"Sunbeem - that's a 1978 R100RS Motorsport you have there, though I suppose you already knew that."

Well, sort of, Daniel.
That is, I knew the name applied, but not what it signified.
A bit of Googling led me to BMRider, and your conversation with Steve, where I learned a bit more.
Now I know that Gertrud is one of only 150 which came to Britain, I shall be even more insufferably smug.
I may even get some blue duct tape for patching the seat.

Sunbeem.

[tbkickstart]

I'm a new member and I have a question, Has anybody ever tried to cut a hole in the stock RS screen like the Parabellum has at the base of there RS screen. Thanks, TB

[SteveD]

I'm a new member and I have a question, Has anybody ever tried to cut a hole in the stock RS screen like the Parabellum has at the base of there RS screen. Thanks, TB

That's an attempt at a sort of naca duct. Yes, it's been done. I'll need to come back later today, after I find it on the 'net. Maybe go to BMbikes (google) and do a search in the Airheads section for naca duct. I'm heading out right now.

[ME 109]

Ah yes, the old parabellum and naca ducts. Takes me back to the good old days.
I haven't got a clue what the last two posts are about.
However, I can make a hole. Where do ya want it and how big?

[SteveD]

Naca ducts...http://www.recumbents.com/wisil/nacaduct/naca-duct.htm

This is a +3" clearview shield that I cut down about 4". The slot in the bottom is what really made the difference in wind noise. The lower the height of the screen the better. I also have a stock screen that I cut down 1 3/4" and it also works well.

Whilst this isn't a naca duct, it's something that someone has done to improve the comfort of the fairing.

I dont know what the optimal size would be. There are many factors to consider. Your height, riding position, windscreen height...etc.
I had the entire helmet in the airstream after I cut the screen down, but it didnt help with the noise. I believe the bottom of the airstream was at the bottom of the helmet. .... After I cut the "duct", it cut the noise by at least 50%. I looked into the NACA duct idea but didnt think it applied to the problem I was trying to solve. Best I can say is experiment...thats what I did. By the way, the size of the cutout on mine is 11" at the base and 2 1/2" in height at the center. I am also using non RS low bars with barbacks. I am 5'-10". Hope any of this helps. I almost sold this bike because of the noise. Now I love it.

Parabellums "duct" & imo, ugly screen.

[DucatiPete]

OK, the deed has been done!
Used Sunbeem's "bendy rod" method and eventually have a screen approx 340mm from front to back ('bout the same as yours Steve, me thinks).
Added the m'bins beading - looks way cool!
On testing I get slightly more wind 'stress' to the head - not buffetting, but the wind sorta wants to keep my head in a narrow stream if i move out of that then i get some buffetting. + More bugs and about the same wind noise. All-in-all, pretty good result IMO - the cool factor definately counter-balances any negatives.
Thank's for all your help boxerheads!
pete
(Pics to come - unusually I took some pics of the operation - but they were taken in a dark shed so the results may be iffy.)

[dougie]

(Pics to come - unusually I took some pics of the operation - but they were taken in a dark shed so the results may be iffy.)

Some shady cobbling done in a dark shed. Uh-oh.