Screens And Helmet Buffeting

[KTMsm]

I recently fitted a small KTM screen to my 950

It has worked far better than I thought at easing the pressure off my chest at 80+ but has caused a lot of wind noise / buffeting on my helmet at 60+

Presumably the only options are to try packing it out to vary the tilt or cutting it down slightly

It's only 4" higher than the headlight mask

[scorcher]

Is it a genuine KTM one or a aftermarket one like Puig. Can’t remember having any problems with the genuine one on my 950.

[Jazoli]

Its the perennial problem, I tried every screen available for my Z1000SX and even changed helmets, I sold the bike because of it, my FZ1 was the same, the only thing that stopped the buffeting was cutting the standard small screen in half, and my Versys too, my Z900RS Cafe has a small bikini fairing, it keeps the wind off my chest and there is no buffeting but my neck didn't half ache after 20 mins at 90mph yesterday!

One day I'll end up on a GS or RT with a barn door fairing because of it.

[KTMsm]

scorcher said:

Is it a genuine KTM one or a aftermarket one like Puig. Can’t remember having any problems with the genuine one on my 950.

It is a genuine KTM one but I think it was for a 690 as the 950Sm one is no longer available

It's a common modification which makes me think they are all pootling around sub 60

[Iminquarantine]

When you are riding at speed, take your hand off the bar (what could go wrong here....) and put it in front of you and move it up and down behind the screen. You will find an area of still air then an area of turbulent air, then an area of clean air. If the turbulent air is at helmet level, that's bad news.

So that's how to diagnose the problem, how to fix it, don't know, sorry!

[poo at Paul's]

Your plan to cut down is the right one IMO, rather than get a taller screen.
My mate messed and messed on his superduke GT with taller and taller screens, honestly, it looked crazy at one point, this screen he had imported from states was like 65cm tall!!
In the end i let him ride my bike with stock screen and he came back bemused as to why he had not buffetting. Then i put the stock adjustable height screen "up" and he tried again and said it was awful!
Stock screen on lowest setting! If it buffets, go lower not higher IMO!

[tvrolet]

Iminquarantine said:

When you are riding at speed, take your hand off the bar (what could go wrong here....) and put it in front of you and move it up and down behind the screen. You will find an area of still air then an area of turbulent air, then an area of clean air. If the turbulent air is at helmet level, that's bad news.

So that's how to diagnose the problem, how to fix it, don't know, sorry!

As above, you might be surprised where the air is coming from that's giving you the hard time. Very different bike indeed, but I got a lot of helmet buffeting on the Indian Chief and the solution is to put air deflectors on the forks. The air behind the screen alone actually comes almost vertically up (even at speed) and then moves FORWARD towards the top of the screen (there was a sort of vertical side-on whirlpool of air behind the screen). The forward air then gets mixed up with the regular air coming backward over the screen and caused a dreadful helmet buffet at my head height. Moving the airflow way below the screen (fork deflectors) drastically cut airflow upwards and solved the issue.

I doubt your solution will be identical as it's a very different bike, but don't assume the buffeting is only down to air coming over the top of the screen. Using a hand to feel the air is fine. but better to get a bit of wool or light string and wave that around behind the screen at speed and see what's happening with the airflow - sure you still have to take a hand off the bars but you can keep your glove on

[KTMsm]

Thanks I'll have to do some experimenting

I seem to remember a weird flap that someone designed that fitted to / near your knees that was supposed to work well - but no one wanted to look that stupid

The BMW F800ST was a very dull bike but it's screen worked perfectly for me, head was in clear air so you felt the speed but there was no pressure on your body

[bsidethecside]

I’m working through this on my KTM 1090 and now waiting for a Puig touring screen. The small std one is good for hot summer days with a vented jacket, but limited weather protection the other 364 days in the UK.

Doing the waving hand test as described earlier, the KTM large screen creates a vacuum at chin level, buffets the top of my head and about visor / ear level the most almighty turbulence. It also seems very adept at directing every suicidal flying insect in Hampshire to my visor’s line of sight.

I’m hoping the Puig will be the Goldilocks screen. At 6ft I’m not abnormally sized, so there must be something out there. Please!