Boulevard C90T windscreen problem

**johnnyflash** · 24th March 2007, 21:50

Any C90T Boulivard riders out there who have found the windscreen a bit turbulent around the helmet, Ive tried right down and all the way up, and finally moved it to slope a bit more towards the rider which helps, but basically its too short for my 5'11" height I think... any suggestions?

**s8306** · 25th March 2007, 07:33

Originally Posted by johnnyflash

Any C90T Boulivard riders out there who have found the windscreen a bit turbulent around the helmet, Ive tried right down and all the way up, and finally moved it to slope a bit more towards the rider which helps, but basically its too short for my 5'11" height I think... any suggestions?

Gidday mate.Can,t comment on the C90t but on my s83 i get helmet buffeting from my sheild, i,m 6' 1". My wife also has the same problem on her 1400 intruder and she,s around 5' 8".Both sheilds are from the Givi range which suit the lines of the bike without being ridiculous but they do stop the wind pushing around the shoulder area which is what we were after.Most cruiser riders with sheilds that i,ve spoken to say they experience some form of turbulence around the helmet, it,s just something i,ve gotten used to.Cheers.

**Toaster** · 25th March 2007, 09:13

Originally Posted by johnnyflash

Any C90T Boulivard riders out there who have found the windscreen a bit turbulent around the helmet, Ive tried right down and all the way up, and finally moved it to slope a bit more towards the rider which helps, but basically its too short for my 5'11" height I think... any suggestions?

Seems to be a constant problem with screens on all kinds of bikes. It's pure luck almost finding a bike you like and a screen that fits your height... so to speak.

I've found its better not having a screen at all, hence the M109R. Body buffeting seems easier to take than head buffeting.

**johnnyflash** · 25th March 2007, 11:14

Thanks for those comments, I think Ive got it down to the best setting by slanting the thing back closer to the helmet, cut buffering down by 80%. I know you can get a 23" screen O-seas (measured from headlight arch to top, (as against 19" std) might just try one when finance allows..

**johnnyflash** · 25th March 2007, 11:18

Too true, Toaster, I quite enjoy the screen off if Im not cruising too far but on long trips ( Akl-Palmerston North) its a bit hard on the old neck

**johnnyflash** · 25th March 2007, 11:21

Thanks for those comments, I think Ive got it down to the best setting by slanting the thing back closer to the helmet, cut buffering down by 80%. I know you can get a 23" screen O-seas (measured from headlight arch to top, (as against 19" std) might just try one when finance allows..

**jafar** · 25th March 2007, 21:54

take a ST1300 for a squirt, they appear to have a good screen setup that is electrically adjustable. if that solves the problem you could measure the screen & rake angle to try on your bike

**Big Dave** · 25th March 2007, 23:17

My test of the bike is in the next issue of kiwi rider.

I experienced some buffeting.

Open face helmet is the easiest solution. I didn't have any prob at all in my Davida. It was quite appropriate behind that big screen too, I thought.

However If that doesn't work for you I found it OK tucked down a bit (slouched slightly more accurately description.) with the screen set up at max.

All screens do it - matter of degrees.

you could also try one of the laminar lip deflector units?

bd

**vifferman** · 26th March 2007, 12:21

High screens - unless very cunningly designed - are worse for turbulence.
Keys are:
- The screen must not have too protrusive a lip on the edge.
- The airflow must be directed well above the helmet, or at the upper chest area.
- If your shoulders/neck are in the airstream, then the collar area of your jacket must be reasonably aerodynamic, or you'll get turbulent airflow around the bottom of your helmet.
- Ideally, your bike should have some means of reducing low pressure behind the screen, otherwise you'll get loads of turbulence caused by the collapsing low-pressure area behind the windscreen. The dreaded Hondas get around this by using methods such as a gap between the bottom of the front of the screen and the fairing to funnel a small airstream through. You don't notice it, but it results in a very smooth airflow.

The worst bike for turbulence I've ever ridden was a BMW GS1200 with the screen in its most upright position: I was completely sheltered from the weather, but it had a very turbulent area behind the screen.

I removed the finishing strip from around my VF500's windshield, after reading a bike test by Alan Cathcart of Aaron Slight's and John Kozinsci's RC45s. Slighty had a strip on the edge of his so he could see the edge and not whack his helmet on it. Cathcart said that the screen on The Little Cock from Little Rock's RC45 had a much smoother airflow, and no turbulence compared to Slighty's. So, I pulled the rubber strip of my screen, and it made a VERY noticeable difference.

**johnnyflash** · 26th March 2007, 17:39

Originally Posted by vifferman

High screens - unless very cunningly designed - are worse for turbulence.
Keys are:
- The screen must not have too protrusive a lip on the edge.
- The airflow must be directed well above the helmet, or at the upper chest area.
- If your shoulders/neck are in the airstream, then the collar area of your jacket must be reasonably aerodynamic, or you'll get turbulent airflow around the bottom of your helmet.
- Ideally, your bike should have some means of reducing low pressure behind the screen, otherwise you'll get loads of turbulence caused by the collapsing low-pressure area behind the windscreen. The dreaded Hondas get around this by using methods such as a gap between the bottom of the front of the screen and the fairing to funnel a small airstream through. You don't notice it, but it results in a very smooth airflow.

The worst bike for turbulence I've ever ridden was a BMW GS1200 with the screen in its most upright position: I was completely sheltered from the weather, but it had a very turbulent area behind the screen.

I removed the finishing strip from around my VF500's windshield, after reading a bike test by Alan Cathcart of Aaron Slight's and John Kozinsci's RC45s. Slighty had a strip on the edge of his so he could see the edge and not whack his helmet on it. Cathcart said that the screen on The Little Cock from Little Rock's RC45 had a much smoother airflow, and no turbulence compared to Slighty's. So, I pulled the rubber strip of my screen, and it made a VERY noticeable difference.

Thanks for that , This screen has NO lip/edge to it at all so nothing to remove there, so far the best I can get it is by tiltling it closer to the helmet,(its a fair way from rider on this style cruiser) and that helps. Ill just have to keep experimenting till I find the right angle/height for my cruise speed of around 110-120 :-) bummer....

**johnnyflash** · 27th March 2007, 14:42

Originally Posted by johnnyflash

Thanks for that , This screen has NO lip/edge to it at all so nothing to remove there, so far the best I can get it is by tiltling it closer to the helmet,(its a fair way from rider on this style cruiser) and that helps. Ill just have to keep experimenting till I find the right angle/height for my cruise speed of around 110-120 :-) bummer....

Just a quick update, I spoke tothe guys at Holeshot (Suzuki) who recon they can get a 23" made locally, so Ill let you know how it turns out.

**chris** · 27th March 2007, 16:11

Originally Posted by Big Dave

I experienced some buffeting.

I've just dropped it off at Haldanes and I have to say the buffeting was terrible, I get less on my DR650! Seat was comfy though.

**johnnyflash** · 28th March 2007, 11:02

Originally Posted by chris

I've just dropped it off at Haldanes and I have to say the buffeting was terrible, I get less on my DR650! Seat was comfy though.

Yeah, when I first picked it up the screen was set midway, and gave me a headache after 20kms, right down or right up is better but not at over 110-120 Ive tilted it back some and that has also improved it but I wont be happy till I get it perfect for my normal cruising speed :-)