Screens and buffeting

[QMC]

Dear all

I had a test ride on a 1200GS today (thanks Wollaston in Northampton) and thought 'what a great bike'. However there was one thing that concerned me a bit - weaving during highish speed motorway runs.

It was very disconcerting, but the bars were definitely moving around, even more so when overtaking a lorry and punching through its bow wave.

I don't think it's the bike; I think it's me. I'm 6'2", and had one too many takeaways if you get my drift. I think my shoulders and upper arms are sticking out into the airflow, and the buffetting this is creating is being transmitted through the bars to the steering.

So, has any one else had this, and are there taller screens that could help?

thanks

 

[Vampire]

I'd suggest that the weave has more to do with tyres and suspension set up, than your height and the screen, unless of course your body is moving around due to the buffeting, and it is you that is inducing the weave.
I am 6'0" and with a standard screen, have ridden at an indicated 225 kph with BMW panniers and Givi Maxia topbox.
I was curious to see how the bike behaved and what top speed I could get in that configuration.
It was moderately windy that day, gusting to maybe 15 knots, and the bike tracked true and stable, no weave, although I felt significant buffeting from the screen.
So I don't think there is any problem with the bike design, just set up.
Ciao,

 

[stumpi]

On the subject of screens, i've just put a slightly taller one on my adventure and its made a huge difference, I reckon I can ride it without earplugs now. for short rides anyway.

 

[chasr]

I disagree with Vampire. This has been discussed before. The weaving is a common 'problem', though not serious. It might be caused by spillage off the side of the screen or, as you suggested, by the airflow catching your (sticky-out) elbows/jacket.

In my experience, the weaving disappears at higher speeds and is not annoying.

rgds

 

[Dave Price]

IMHO, I think most of it is caused by a stiff upper body, transmitting movement to the bars, which, due to the quick steering, causes a weave.
If you want to experience weave on a bike, try riding a Honda 1300 Pan European at any speed.

 

[Paul Wakefield]

I reckon its aerodynamic because, on a TOTALLY still day, it is unnoticeable and is definitely worse if there are large vehicles around.

Having said that, jacking the rear preload right up helps but does not eliminate it.

Paul

 

[Tomcat]

preload

I found the same front end vagueness at 90+ when I took the 1200 for a test ride - the bike had a definite slight slow weave, but not bad enough to be scary. Tobers suggested upping the rear preload, and on my bike I have now softened the front by one notch and upped the rear preload a bit. It seems to have done the trick. The front end still feels a tad 'remote' compared to all the other bikes I have ridden with telescopic forks, but I think the telelever design may be responsible for this. It brings other benefits so its a case of 'win some, lose some', as all bike front end steering/suspension/braking designs involve compromise somewhere.

TC

 

[QMC]

If you want to experience weave on a bike, try riding a Honda 1300 Pan European at any speed.

I rode a Pan 1300 last weekend but didn't notice a thing. Horses for courses I suppose.

 

[jlabro]

not much to say here...

Interesting thread ..

 

[Davel]

5ft 10 and a bit overweight too.

Find the weave annoying, when there's heavy vehicles around and also quite a bit of buffeting around the head with the screen on lower settings.

Haven't tried the screen at its highest yet, but it should eliminate the head buffeting considerably.

Maybe they're not designed for speed!

 

[Rod]

I'm 5' 11" with standard seat on lowest setting. I found the best setting to eliminate buffeting was with the screen on the lowest setting, it got worse the more vertical I made it.
Then I fitted some Tobinators and set the screen at the same low angle but raised higher & nearer to me ( thats three notches down from the top of the Tobinators & one notch down from top on the side adjuster). This setting seems the best so far, it seems to give a clean air flow to the helmet & raise the air flow over your shoulders. I am going to Norwich & back on Saturday (about 300 miles) so this will be a good test.

 

[Mr K]

Drop the front shock a click - They come set up like bloody speedboats from the factory.....er nose-up, that is.