taller wind screen for rt?

General discussion of the BMW R1200RT/R1250RT
guest2360

Re: taller wind screen for rt?

Post by guest2360 »

beemerbaz wrote: £5 each top up [emoji33]

I would be interested to know the actual consumption figures if you had them ?
It was a 2009 SE Stock bike with a top box.  Fast or slow it averaged about 50mpg  over the 18 months I owned it.  On the trip we were running the tanks quite low between fillings and the difference was always just under 4 ltrs. We could only put it down to the screens. So I reckon even a bigger screen, even more wind resistance..   
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David.
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Re: taller wind screen for rt?

Post by David. »

If a Bike does 55 MPG, compared to a Bike which returns 45 MPG, (typically what I get), that's a difference of -18%.

At today's prices, £5 will get you a gallon of fuel.

My RT has a 27 litre (6 gallon) fuel tank, putting 1 gallon less in to fill it up is nearly -17% difference.

I can well believe the example quoted.

Riding style & loading can clearly effect MPG, on the same Bike, I've covered over 300 miles on a tank full, returning around the 55 MPG mark, when cruising on a motorway.
Last edited by David. on Sat Jan 31, 2015 11:29 am, edited 1 time in total.
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Levisp
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Re: taller wind screen for rt?

Post by Levisp »

RTman10 wrote: 2 identical RTs  one with the screen up and one down. Over a 600 mile trip each time we filled up the bike with the screen down cost £5 less to fill even though it was more heavily loaded.

Thats quite interesting. I see you have a top box I bet that makes a big difference to mpg. Top box and panniers must create a fair bit of drag, so must effect mpg as much as screen position.


Was the luggage setup the same on both bikes?
guest2360

Re: taller wind screen for rt?

Post by guest2360 »

Standard BMW luggage with the 42 ltr box on both bikes so they had no effect on the difference.  I cant see the drag on the panniers or top box having any noticeable effect on consumption.  Full to the brim maybe. . 
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Levisp
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Re: taller wind screen for rt?

Post by Levisp »

Screen it is then. Must admit I cannot see the need for taller screens. I'm 6ft 1in ride on a high seat in the high position and generally have the screen mid way. Only ever have it fully up when its pissing down. In the full up position I'm just looking over the top anything higher I would have to look through the screen. My only minor complaint is that my upper arms and shoulder get quite a wind blast, a wider screen might divert the airflow better. However I'm sticking with the original for the moment.
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Re: taller wind screen for rt?

Post by step2534 »

I might be wrong but I would have thought that ,

If you didn't have a screen on, then your body would  cause more resistance than having one. After all the screen is shaped to cut down on resistance, whereas your body would be more like a sail because of the shape

If that was the case then surely it wouldn't matter how high the screen was it was.
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Levisp
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Re: taller wind screen for rt?

Post by Levisp »

I do not think its the height of the screen rather than the angle of the screen to the airflow. With the screen fully up its pretty vertical and that creates the drag because of turbulent airflow spilling off the top.
guest2360

Re: taller wind screen for rt?

Post by guest2360 »

Levisp wrote: I do not think its the height of the screen rather than the angle of the screen to the airflow. With the screen fully up its pretty vertical and that creates the drag because of turbulent airflow spilling off the top.
I agree. A raised screen is nearly upright and makes a great air brake.  So the bigger the screen the more brake and higher mpg. 
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Re: taller wind screen for rt?

Post by step2534 »

Yes that makes sense.  I like the phrase  Air brake 
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Re: taller wind screen for rt?

Post by beemerbaz »

I guess we buy after market screens for varying reasons, mine is because it looks darn good [emoji106]
Love my family almost as much as my 90th anniversary RT
step2534
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Re: taller wind screen for rt?

Post by step2534 »

Beemerbaz,  That's as good a reason as any.
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Re: taller wind screen for rt?

Post by 7vwh »

I want a taller screen because I'm bloody tall! Still looking.......
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stelyn
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Re: taller wind screen for rt?

Post by stelyn »

7vwh wrote: I want a taller screen because I'm bloody tall! Still looking.......
"The debacle of using this outfit has concluded. They sent the wrong screen, argued like feck that I'd got the correct one, I spent £30 sending it back and they quietly refunded my original cost (no return postage) and didn't even send any email to let me know!
Shower of Scheiße"

Hi  7vw, have  deleted this lot of my `PC'  after the crap service and  shameful lack of `customer care' they demonstrated for you , will never get my custom  >:( 

                                            www.bmw-motorrad-store.co.uk      :shirty:
Last edited by stelyn on Tue Feb 03, 2015 9:53 am, edited 1 time in total.
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Levisp
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Re: taller wind screen for rt?

Post by Levisp »

7vwh wrote: I want a taller screen because I'm bloody tall! Still looking.......

Have you seen this one:


http://www.nippynormans.com/products/wu ... -30370-202


Comes in clear or tinted.
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richardbd
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Re: taller wind screen for rt?

Post by richardbd »


Doesn't the Pope of this parish have one of those fitted?
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