PDA

View Full Version : How to adjust windshield to get rid of buffeting?


DaveInPA
26th September 2008, 11:58
I installed my new Memphis Shades El Paso yesterday and I'm getting some terrible helmet buffeting with my full face helmet. Any speed above 30mph I feel like my eyes are going to rattle out of my skull.

I didn't have any time to adjust the angle of the shield yesterday, so I need to get on that once the rain stops this weekend. What adjustments help with buffeting? Right now the shield is running at about the same angle as the forks. Would making it stand more vertical help the air to flow over my head instead of directly into it? And as far as height, where should the top of the shield be? Even with my nose?

Thanks
Dave

Jt1200r
26th September 2008, 12:08
get rid of windshield

DaveInPA
26th September 2008, 12:10
Wow, what a helpful answer. :rolleyes: Why can't anyone ever post a legitimate question around here without getting stupid responses like this? :doh

ColinB
26th September 2008, 12:28
Wow, what a helpful answer. :rolleyes: Why can't anyone ever post a legitimate question around here without getting stupid responses like this? :doh

Perhaps it's because you never say "Thank You" to people who go out of their way to help you with your questions!

Here.

Here.

DaveInPA
26th September 2008, 12:33
Perhaps it's because you never say "Thank You" to people who go out of their way to help you with your questions!

That was one thread. I've made it a point to be more courteous since then. And it's not just me that gets nonsense replies like that. It happens all the time to almost everyone it seems.

ColinB
26th September 2008, 12:36
That was one thread. I've made it a point to be more courteous since then. And it's not just me that gets nonsense replies like that. It happens all the time to almost everyone it seems.

Glad to hear it.....except for this thread. A "Thank you" is well overdue!

EDIT: oops....thanks for thanking people..it helps the world go round!

DaveInPA
26th September 2008, 12:39
Glad to hear it.....except for this thread. A "Thank you" is well overdue!

EDIT: oops....thanks for thanking people..it helps the world go round!

Yeah . . . replied to you in that other thread.

Oh, back to this topic, I don't want to get rid of my windshield. It's going to start getting colder real soon here in PA and I want to ride as far into fall as I can. And the shield will help me do that. I could care less if it's "cool" to have it on the bike. Function over form every time.

ColinB
26th September 2008, 12:49
Try this thread...it's about windshield buffeting.

Phaedrus
26th September 2008, 12:52
When I'm sitting on my bike, my windshield comes up to my nose. It's as high as can be while still being able to see directly over it at the road. I find I get very little wind buffeting as most of it goes over my head (like a lot of things in life).

Of course on a windy day, the windshield acts like a bit of a sail.

JayFL459
26th September 2008, 12:57
Nose Level Works for me with the Memphis Shades 17".. Not saying is perfect for every condition but 95% of the time have no buffeting at all and like to see above the windshield about 2" why went with the 17"...

gypsysailor
26th September 2008, 12:59
I didn't think it was such a stupid answer. I put a shield on my bike and adjusted it every way possible. The only way i could make it ridable was to put it on someone elses bike, So I did. Some folks like a shield, some don't. I found that a windshield does a good job of deflecting the straight on wind but the buffeting comes from below the shield and the only way to get rid of that is to add a set of lowers. I have learned to just enjoy the honest wind with no shield.

whittlebeast
26th September 2008, 13:12
I did about a week of wind tuff testing till I got it correct. The tuffs were on both my windshield and helmet getting it correct.

http://www.ncs-stl.com/motorcycle/Side.JPG

Weo
26th September 2008, 13:35
I dont experience any buffetting with my small shield, but did on my larger one.

Put some time trying it lowered, angled, and at different speeds. If you like it better the lower it goes, you can always just cut some off the top. I ended up using a 15x15 shield that's meant to take the wind off of my chest, but it ends up taking about 50% of the wind off my head without any buffetting. Its top sits level with my clavicle.

ParrotHead
26th September 2008, 13:37
I did about a week of wind tuff testing till I got it correct. The tuffs were on both my windshield and helmet getting it correct.


Wow, I have not used wind tufts since my sailing days 30 years ago!

Can you explain this further, perhaps showing where the tufts were located?

(Dave, in case you don't know, wind tufts are pieces of string, yarn, cassette tape, etc. used to make the air currents visible)

DaveInPA
26th September 2008, 13:37
Thanks for the tips so far guys. The worst part is it's going to be raining all weekend so I don't even know when I'll have a chance to play around with it!!

As far as moving it down (lower), the El Paso has a headlight cut out that is only above the headlight if the shield is all the way up the fork tubes. If I move it down and some of the plastic is in front of the headlight, is that going to hurt anything? (melt the plastic, etc?)

rfranz1952
26th September 2008, 13:41
The buffeting with a windshield generally comes from below. When a windshield is mounted, it stops the straight-on windtream and deflects that over the riders head--assuming the shield is properly sized and adjusted--but it also creates an area of low pressure behind the shield. As a result, part of the windstream that is in the area around the legs is "sucked" upward, and can create helmet/head buffeting from below.

The smaller the shield, the smaller the low pressure area, and the less potential for bufeting. However, a smaller shield will be less effective at diverting the straight-on airstream.

Need to find the right combination.

Leaning back in the seat may help pull your head out of the stream.

ColinB
26th September 2008, 13:42
I did about a week of wind tuff testing till I got it correct. The tuffs were on both my windshield and helmet getting it correct.

http://www.ncs-stl.com/motorcycle/Side.JPG

Knowing you, I'm surprised you didn't use a wind-tunnel.:p:p

http://people.bath.ac.uk/ensmjc/Research/Motorcycles/ST1100/hondap~8.jpg

DaveInPA
26th September 2008, 13:44
The buffeting with a windshield generally comes from below. When a windshield is mounted, it stops the straight-on windtream and deflects that over the riders head--assuming the shield is properly sized and adjusted--but it also creates an area of low pressure behind the shield. As a result, part of the windstream that is in the area around the legs is "sucked" upward, and can create helmet/head buffeting from below.

The smaller the shield, the smaller the low pressure area, and the less potential for bufeting. However, a smaller shield will be less effective at diverting the straight-on airstream.

Need to find the right combination.

Leaning back in the seat may help pull your head out of the stream.

Very good info, thanks. That's encouraging (the leaning back part). I have taller risers on the way, so having the bars higher will natrually cause my riding position to be more leaned back. Hopefully that will be helpful.

milmat1
26th September 2008, 13:46
My detachable HD shield causes buffeting really bad, And it's not adjustable ! I don't use it often, Only when it's cold or raining.
The buffeting feels like it's gonna rattle your teeth out !

DaveInPA
26th September 2008, 13:47
My detachable HD shield causes buffeting really bad, And it's not adjustable ! I don't use it often, Only when it's cold or raining.
The buffeting feels like it's gonna rattle your teeth out !

That's one of the main reasons I went with the Memphis Shades. Very adjustable. And about half the price :clap

bigjnsa
26th September 2008, 13:49
Dave, you never said what kind of helmet you have. In my experience, this has a lot to do with the amount of buffeting.

DaveInPA
26th September 2008, 13:52
Dave, you never said what kind of helmet you have. In my experience, this has a lot to do with the amount of buffeting.

A half and a full. I rode with the full yesterday.

FoxsterUK
26th September 2008, 13:53
Wow, what a helpful answer. :rolleyes: Why can't anyone ever post a legitimate question around here without getting stupid responses like this? :dohActually that would have been my suggestion too. There just seems to be something about the aerodynamics (or lack there of) with the Sportster that makes for lots of buffeting with screens.

I have seen a few partial fixes by putting it on at a steep backward angle or adding some extra wind-breaks below the screen or just swapping helmets but I don't think there is really a magic bullet fix. So getting rid of the screen is perhaps the best suggestion.

Fox

ParrotHead
26th September 2008, 13:58
The buffeting with a windshield generally comes from below.


The best way to find out is to start riding and hold your hand out in front of you, and move it up until you feel the turbulence. If the wind is coming over the shield and hitting your helmet, its from above. If you feel it around your chest, its from below.

Once dialed in, I really like having a shield. I can ride comfortably at any speed I wish, and little wind noise so I can hear cars around me.

I never knew why my friends wore ear plugs until I rode without my shield one day when I was wearing my 1/2 helmet.

emzdogz
26th September 2008, 14:19
Helmet seems to make a diff.
For me all this is only an issue, usually, at sustained riding over say 65 mph.
i.e. slabbin' it.
For this type of riding I had to lose my Bell helmet which incorporates a visor. Too bad as I basically LOVE that helmet. The visor was just catching too much wind and trying to pull my head off under some circumstances.

Like Whittlebeast's pics show, I also think that tipped back and elevated some will be the final solution IF I keep a shield at all.
On my recent longish road trip I had mine (trimmed down Memphis Shades Del-something or other) tipped back some and it was pretty good, actually - with a full face.
Some buffetting I think its impossible to get rid of.
If someone were very serious about it, I'm thinking lowers would be involved.

The thing that bugged me to DEATH on my trip is that the shield was about 1/2 inch up too high and so a bit more in my line of vision than I'd like. Also I noticed it is on there slightly crooked. Even tho it looks equal at the headlight cut-out, somehow it is cocked slightly counter-clockwise, viewed from the seat...and so I found myself turning my head to "match" its angle. LOL! not good!

So more fiddling to come!
fwiw, I don't find the Memphis Shades particularly easy to change the angle of - at least not very exactly.
Wondering how some of you who have fiddled w/position of these bar mount MS shields do it?
What I've come up with is slightly loosen ALL the hardware allen screws (except the ones that go to the plastic itself) wiggle the shield into position while its all loosy-goosey and then try to hold it there while you snug up the Allen's. But if you have to completely remove the main "blocks" that hold it to the bars....its just a total PITA.
It IS very adjustable, sorta, as they advertise....but its not that super easy, I find.
A 2nd set of hands helps, and I don't have that. My dog has proved fairly worthless at holding the shield for me.
;)
I'm wanting a Rifle mini-fairing now.

Anyway as far as the shield, I'm thinking its one of those things like a seat or a bar/riser combo, when you finally find the RIGHT one (one you can live with), its just a beautiful thing!

scottgearman
26th September 2008, 14:30
get rid of windshield +1

In my experience with , first a compact and then a standard height sheild, buffeting is constant. I even went so far as to buy and install a LAMINAR L.I.P. which is designed to fix the buffeting... No difference.
Just for the sake of experiment I recently ran a windsheild again to see if the front end being 4 inches higher and a 36 degree rake (the sheild clamps to the fork tubes) would make a difference.... NOPE.

Lots of guys here will tell you that buffeting is NOT an issue and many will tell you the buffeting almost shakes their skulls loose... It sounds like you are one of the latter..... Get a good pair of glasses and tie a bandana over your face when riding highway to keep from sandblasting your face and get into the wind.


http://www.laminarlip.com/fxdxfront.jpg

bigjnsa
26th September 2008, 15:19
+1

In my experience with , first a compact and then a standard height sheild, buffeting is constant. I even went so far as to buy and install a LAMINAR L.I.P. which is designed to fix the buffeting... No difference.

Weird. I rode my dad's BMW with the Lamar Lip and it was an amazing difference compared to my bike. Virtually no buffeting at all.

Just for the sake of experiment I recently ran a windsheild again to see if the front end being 4 inches higher and a 36 degree rake (the sheild clamps to the fork tubes) would make a difference.... NOPE.

Lots of guys here will tell you that buffeting is NOT an issue and many will tell you the buffeting almost shakes their skulls loose... It sounds like you are one of the latter..... Get a good pair of glasses and tie a bandana over your face when riding highway to keep from sandblasting your face and get into the wind.


The problem is some of us have problems hanging on with no windshield. At 75 I feel as if I'm going to be lifted off the bike, so I have to use a windshield.

Jt1200r
26th September 2008, 16:06
see you dont need a windshield on your sporty. you have a street glide

DaveInPA
26th September 2008, 16:08
see you dont need a windshield on your sporty. you have a street glide

Yeah but I refuse to ride that thing to work. I work in a not great part of town and if one of my bikes is gonna get messed with I'd rather have it be the less expensive one!

Hot Rod Sporty
26th September 2008, 16:14
Wow, I have not used wind tufts since my sailing days 30 years ago!

Can you explain this further, perhaps showing where the tufts were located?

(Dave, in case you don't know, wind tufts are pieces of string, yarn, cassette tape, etc. used to make the air currents visible)



Isn't that called a 'TELLTALE'?;)

Jt1200r
26th September 2008, 16:15
i can understand that

whittlebeast
26th September 2008, 16:52
I you want to really mess with the Harley croud, Google vortex generators

see http://en.wikipedia.org/wiki/Vortex_generator

Trust me when I claim that the wing is not there for the just the bling, it works.

http://www.vividracing.com/catalog/wm.php/images/mrvortex.jpg

doxbike
27th September 2008, 03:23
I installed my new Memphis Shades El Paso yesterday and I'm getting some terrible helmet buffeting with my full face helmet. Any speed above 30mph I feel like my eyes are going to rattle out of my skull.

I didn't have any time to adjust the angle of the shield yesterday, so I need to get on that once the rain stops this weekend. What adjustments help with buffeting? Right now the shield is running at about the same angle as the forks. Would making it stand more vertical help the air to flow over my head instead of directly into it? And as far as height, where should the top of the shield be? Even with my nose?

Thanks
Dave

Exactly opposite, tilt it back. Ask me how I know? I've been thru hell with windshields. Every body is different-find the angle that works for you

Weo
27th September 2008, 11:22
I you want to really mess with the Harley croud, Google vortex generators

see http://en.wikipedia.org/wiki/Vortex_generator

Trust me when I claim that the wing is not there for the just the bling, it works.



Hmmm... sounds like it is meant to be used to enhance "trailing-edge control surfaces", bringing more wind to the end of the part... in particular ones that run close to horizontal or parallel to the wind flow. Wouldn't this effect be minimal on a shield that is almost perpendicular to the airflow?

Carl-04XL
27th September 2008, 13:22
The buffeting with a windshield generally comes from below. When a windshield is mounted, it stops the straight-on windtream and deflects that over the riders head--assuming the shield is properly sized and adjusted--but it also creates an area of low pressure behind the shield. As a result, part of the windstream that is in the area around the legs is "sucked" upward, and can create helmet/head buffeting from below.

The smaller the shield, the smaller the low pressure area, and the less potential for bufeting. However, a smaller shield will be less effective at diverting the straight-on airstream.

Need to find the right combination.

Leaning back in the seat may help pull your head out of the stream.

Wind buffeting: Surprisingly, or not, a tank bag helps here. I got one before putting on the saddle bags and it helped. (I've had a H-D quick detach w/shield since I got the Sporty.) I just used it again on my Milwaukee trip and it definitely helped, and not just with helmet wind-buffeting. It also provided a place to lean on when the butt got tired of being sat on... :laugh:laugh:laugh

Anything that reduces the low pressure area behind the w/shield (and fairings... a windshield is just a very minimal fairing...) helps reduce the 'bouncing helmet' syndrome. Vetter used 3" pop-out vents on their fairing windshields to reduce the low-pressure area. And you should see the Corbin Adjustable Trimtab Faring (http://www.corbin.com/product/trimtab.shtml). They claim vastly reduced wind buffeting. Not my style, though.

As for the optimal height, it really is a matter of choice. I've seen windshields on Harley's geezer-glide fairings that were only a couple of inches high. Hardly enough to actually qualify as a windshield. And, I've seen windshields that the rider had to look through to see low flying aircraft :wonderlan. Not going to get that 55mph june bug in the forehead with one of those. :D

The general rule is where you can easily see over the shield while looking straight ahead, but you can tuck down a little and get mostly full protection from rain or bug swarms.

jamesr242
30th September 2008, 18:53
get rid of windshield

+1 on this. I bought an HD standard height, quick detach off craigslist and after only a minute or two of riding on the highway, I was starting to get a HUGE headache from the ridiculous buffeting. Never used it again and now I'm trying to get rid of it. FWIW I also have a full face helmet (HJC, I think its a CL-12) and am 6'1. I much prefer the ride without the shield.