Helmet buffeting

[Winston001]

Time and tide have impinged ever so slightly on the old visual acuity and I'm having trouble seeing well out of a helmet.

At modest speeds such as 80k it is ok but above that I find helmet buffeting blurs the road ahead. A lot of this has to do with riding behind the large R80RT fairing so I've been playing around with bits of cardboard to raise the top edge and find a sweet spot.

The buffeting actually comes from behind me. If I lean forward it eases but I don't want a sports bike posture on the R80 - feels unnatural and not good for the back.

When I tested the Ducati there was similar buffeting but I put that down to a lot more air being redistributed at a faster rate. The ST4 has a small so-called touring fairing and it isn't bad.

What I'm worried about is that if I cannot sort out this helmet vibration for any bike, then things look grim. All joking aside, I'm quite worried about this.

[Ixion]

I'm not clear why helmet buffeting should cause the road to blur?

One solution however (though probably not applicable to your R80) is an electric screen, as fitted to later BMWs, FJR1300 etc. They are one of the most useful things ever invented for bikes, you can raise or lower them on the move to get exactly the position you need for any given speed, wind direction etc. They usually move up and back, which avoids the need to move forward you speak of.

Another solution would be an open face helmet.

(BTW what does the tide have to do with it ?)

[AllanB]

From my 27 years of riding it appears that all helmets have some buffeting and noise. My Suzi 1200s was really loud until I trimmed the screen down about 30mm.

My new Hornet is a lot quieter (same helmet) all naked (bike that is).

It always appears that the 'sweet spot' (not to be confused with the 'wet-spot') is always a few cms taller than you are!

Try it without the screen as well.

If you have a old helmet (10yrs or so) it would be worth replacing as well.

[Winston001]

(BTW what does the tide have to do with it ?)

Pedant!! :headbang:




...........but just for you Ixion, the phrase "time and tide" cames from early English and..." the origin is uncertain, although it's clear that the phrase is ancient and that it predates modern English. The earliest known record is from St. Marher, 1225:

"And te tide and te time þat tu iboren were, schal beon iblescet."



While it may draw in a figurative way from King Canute's baiting of his courtiers by bidding the tide not to come in, the word tide in ancient meaning meant seasons, the passing of time.

A vestige of this remains today in "good tidings". HTH. :yawn:

[Winston001]

I'm not clear why helmet buffeting should cause the road to blur?


It's a quantum thing. As you know Einsteins Special Theory dealt with two moving objects relative to each other and when above 80k in my universe the road moves in relation to the bike. This movement is called blurring and introduces incoherent photons to the ocular nerve which cannot decode the information.


Damn its late, must get some beauty sleep. :msn-wink:

[Winston001]

From my 27 years of riding it appears that all helmets have some buffeting and noise. My Suzi 1200s was really loud until I trimmed the screen down about 30mm.

My new Hornet is a lot quieter (same helmet) all naked (bike that is).

It always appears that the 'sweet spot' (not to be confused with the 'wet-spot') is always a few cms taller than you are!

Try it without the screen as well.

If you have a old helmet (10yrs or so) it would be worth replacing as well.

Thanks Allan, good ideas and I'll take the screen off tomorrow - or maybe right now since I'm still awake.

I admit I'm wondering if the fairing is causing this and I'll have to go naked. Unfortunately I've rather got used to being dry when all around are shivering and bedraggled. The R80 screen is magnificent but on the other hand it is interesting to note modern BMWs and other tourers don't have the same size.

One experiment I did (as you allude to) was to lower the screen (there is manual adjustment) and add 40mm of cardboard. It seemed counterintuitive but the result was the screen rake increased backwards and suddenly much of the buffeting was gone. I suppose if I could rake it even more it might just solve the roiling slipstream behind my head.

I appreciate your thoughts. Yes my helmet is reasonably new.

[Delphinus]

Need a wind tunnel with that smoke trails stuff so you can see where the wind flows are going :D

[Winston001]

Yeah good thought. Not a lot of those around here although come to think of it, all that would be needed is a smoke flare when a good sou'wester is blowing up from Antarctica. Happens often enough. ;)

[Bob]

Amazing the difference the screen can make. I know when I had a GPZ500S, with the standard screen I got a lot of wind blast directly into my chest. SO I bought a taller screen with an edge that curved slightly upwards - and it redirected the wind over my head.

By the sound of things, experimenting with different screen positions has worked for you - I wonder if you have subconsciously changed your riding position a bit, which has brought this issue up?

[Winston001]

An interesting point Bob. Just tried to take the screen off but it is more fiddly than I can be bothered with at this hour. :D:

I've been thinking about putting "wings" on the screen - I notice a lot of sport fairings have a scooped profile, so it is worth trying. What I need to achieve is to move the roiled air back slightly. Off to bed.

[AllanB]

BMW had a adjustable wing on the top of one of their touring screens a few years ago, pretty sure it was the K100 & 75 series. You could tilt it op and down like a plane wing flap.
Sound like a Xmas holiday project :niceone:

See image below which clearly shows this.

[Ixion]

Pedant!! :headbang:




...........but just for you Ixion, the phrase "time and tide" cames from early English and..." the origin is uncertain, although it's clear that the phrase is ancient and that it predates modern English. The earliest known record is from St. Marher, 1225:

"And te tide and te time þat tu iboren were, schal beon iblescet."



While it may draw in a figurative way from King Canute's baiting of his courtiers by bidding the tide not to come in, the word tide in ancient meaning meant seasons, the passing of time.

A vestige of this remains today in "good tidings". HTH. :yawn:

Actually 'tide' is two different words. 'Tide', from OE tid a division of time, a period. This gives us the tides of the sea and such phrases as eventide christmastide. The other 'tide' derives from ME tidan a happening or event. This gives us to betide, good tidings. The 'tide' of time and tide is the latter: the meaning being "the passage of time, and the events that have happened" .

I'm sure that experimentation with the screen would do the trick. The problem may be to find a setting that works for all wind speeds and directions. I use the electric screen on my BMW while riding, you can alter it on the move, and the difference it makes is extraordinary. A press of the switch to raise or lower it a bit and you go from noise to complete silence. But I must often change it a little later. So getting a constant position that works perfectly is probably not practical, but you should be able to improve matters.

[Winston001]

Actually 'tide' is two different words........

I'm sure that experimentation with the screen would do the trick.....

You are a pedant's pedant man - I love it. :rockon:


I'll continue to play around with the bits of cardboard as I have been this afternoon. Looks like I'll just extend the screen by 60mm or so across the whole width and ride for a while like that.

Interestingly a mate suggested I ride with my visor loose and it seems to make a difference.