Pavement paranoia!

wildbears said:

Thanks for the comment.

Perhaps you can provide us with a link.



Footnote: To clear up any possible confusion about post #58, these are just two examples of wind-buffeting. Buffeting can occur just about anywhere on the rider and the rider's helmet depending on a large number of variables. Post #58 is not about wind-noise.

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View attachment List of References.pdf

34 journal and magazine articles. Most will provide additional references.

36654 said:

If someone could quantify the difference between noise and buffeting that would be helpful. I fear we're talking around individual perceptions of high and low frequency noise.

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I hope I made it clear that the wind noise makes the buffeting seem worse. Buffeting is when the wind slaps you around. Noise is noise.

Anyname said:

I hope I made it clear that the wind noise makes the buffeting seem worse. Buffeting is when the wind slaps you around. Noise is noise.

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When I say quantify, I mean what would you measure to determine the magnitude or impact of this phenomenon?

How to avoid a deer strike.

<iframe width="737" height="415" src="https://www.youtube.com/embed/joWPikOaoqs" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

.....

Can you say "NOT PAYING ATTENTION"!!! Sometimes it just can't be avoided, but this guy was in la-la land concerning his riding. Did do pretty well with his profanity though .

Might want to check your settings in relation to your time zone.
Settings in the upper right hand corner of the page.
OM

Where did you go WB?

wildbears said:

Riders can test the significance of these studies on their own.

To check the difference between turbulent and clean air, carefully stand on the pegs while riding at speed.

This moves the helmet from the turbulent air trailing most windscreens into undisturbed clean air that exists higher up.



While the study's test results are accurate, they don't apply to whether clean air decreases wind noise.

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Don't fall off.

PGlaves said:

Don't fall off.

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In the prior posts, I was to get "clean air" by riding on cruisers with fork mounted fairings, but not Goldwings. Now, I'm to get "clean air" by standing on the pegs.

As for me, the sun rises in the east and sits in the west, proving that the sun revolves around the earth. I see for myself every day.

wildbears said:

Alcohol and Caffeine.

Drinking these together combines decreased motor skills and heightened emotional lability.

The rider may become less risk adverse, more prone to anger/road rage, and less able to handle resulting situations.

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Caffeine affects people differently. I've been treated for caffeine intoxification twice by the VA. Now that I'm down to 3 24ounce coffees from 5 per day, my riding skills are not diminished in the least. I function just fine on 3 24 ounce coffees a day. While someone else may have one small cup of coffee and get the jitters.

Two police motor courses passed while on caffeine, if the skills were diminished, I doubt I'd have been able to pass the courses based on your idea of decreased motor skills.

There are NO absolutes in the world.

wildbears said:

I guess my post needed to be clearer.

Sorry.

It is meant to suggest that alcohol decreases motor skills.

Not that caffeine does this.

Many studies show caffeine to increase performance skills.

Caffeine is metabolized by the body's cytochrome p450 enzyme system.

Genetically, individuals may be high, normal, low, or null metabolizers.

This is reflected in an individual's response to caffeine dosage.

Null metabolizers may be hypersensitive to caffeine while high metabolizers can handle higher dosing.

Additionally, as with many stimulant drugs, tolerance occurs with repeated exposure.

Part of the reason is caffeine suppresses the release of endogenous "wake-up chemicals".

This explains the progressive need for more cups each day to reach the desired state of alertness.

OTOH, null metabolizers may experience a progressive accumulation of caffeine with just a single cup each morning resulting in a hypomanic state in susceptible individuals.

Hopefully you WERE NOT consuming both alcohol and caffeine during testing.



Here's my original post again:

Alcohol and Caffeine.

Drinking these together combines decreased motor skills and heightened emotional lability.

The rider may become less risk adverse, more prone to anger/road rage, and less able to handle resulting situations.

Thanks for your input.

Good to see that some are following this thread.

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I don't drink alcohol at all. Fluid intake is limited to coffee and water. I don't do soft drinks/soda at all either. Thanks for the clarification sir.

Dress for the crash, not the noise level.

PGlaves said:

Dress for the crash, not the noise level.

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In the words of Dug the Dog.............."SQUIRREL"

wildbears said:

As for the role helmets play with wind noise, per Dr. John Kennedy (Trinity College Dublin), et. al., wind noise is accentuated by the "Coke Bottle" effect (my term) of air passing under the helmet across open spaces between the rider's head and the helmet. And of course, if the air is turbulent even more noise is created.

This is especially true for full face helmets with the visor all the way down.

For example, the noise with a late model Gold Wing mostly disappears when ridden bare headed as opposed to a full face helmet with the visor down.

Many Gold Wing riders rode sans helmets back in the day.

And the Indian Chief Vintage (post #70) is even quieter when wearing a full face helmet if the visor is all the way up.

PS!

The above is a part of a continuing discussion of factors related to wind noise.

Subsequent posts suggest that the above could be misinterpreted by someone as a recommendation to not wear a helmet in order to decrease wind noise.

Please understand the example of Gold Wing riders not wearing helmets in the past is only used to collaborate Kennedy's research.

Of course it is not a recommendation to ride without a helmet....

Many thanks for the followup posts.

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Have you been in contact with Dr. Kennedy? And, do you have a document saying he agrees with your statements?

wildbears said:

If you have additional concerns that weren't addressed, please send me a PM.

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Well, I do. No pm requiared. Any nonsense that purports to justify why people don't wear helmets is balderdash. I have read it all: neck strain; peripheral vision; whiplash; and now noisiness. All of these silly excuses have next to no merit compared to the known ability of helmets to reduce fatalities and serious head injuries. NOTE: I said reduce not eliminate. But when peer pressure, pirate costumes, pseudo science and other goofiness comes between a rider and proven safety improvements from a helmet I call bovine excrement.

Never thought I'd do it but I'm putting a small driving light on my airhead. Looks stupid but I'd look stupider in the ER. Car drivers don't know what they're doing out there and last season it was worse then bad. After passing a watered down no texting etc. law, drivers still don't give damn. The tickets for non-compliance are a joke. It's reality not paranoia. Follow the direction map on yer dash is another elephant in the closet. Gut check for texting would be suspension of license for six months and impounding of vehicle. It's like a DUI situation. Also installing a hype-light in the rear. Two cents.

Put both on my old K bike too. Also made a plastic bulge over the RS helmet buffeting windshield. Gives some clean air onto my helmet. Looks stupid too.

wildbears said:

Aggressive Riding and Lane Changing Risks



https://www.hindawi.com/journals/ddns/2017/7328562/

Other known factors:

• Fatigue.
• Improperly looking prior to lane change.
• Driver distraction due to map or gps reading.
• Under the influence of drugs/medications and/or alcohol.
• Weather conditions limiting the drivers ability to see clearly.

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How in the hell is anyone but a higher education mathematician supposed to make sense out of anything in that link? I'll continue to rely on my senses, skills and peripheral vision when riding. Science is fabulous but only when one can make sense out of the technical data and properly apply that to the street. IMO, this link doesn't accomplish that,

brownie0486 said:

How in the hell is anyone but a higher education mathematician supposed to make sense out of anything in that link? I'll continue to rely on my senses, skills and peripheral vision when riding. Science is fabulous but only when one can make sense out of the technical data and properly apply that to the street. IMO, this link doesn't accomplish that,

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In summary ............ Speed, following distance / gap and "driving tendency" are dominate factors in this model. Which sorta supports your observation of nothing new.

However it is a traffic risk model developed by Chinese researchers at a Chinese University using Chinese Gov't funds. Potentially, this little risk model could be an element in the design of artificial Intelligence software for a "smart" autonomous car or other vehicle.

I went to pick up a box of parts, on the floor.
I ripped one nail off half way up my finger.
Never felt a thing, but noticed some blood
Wonder how the bones would do on a simple impact.
Kind of worries me.

ATGATT.

Our state and federal agencies do a lot of good work in the area of motorcycle safety. While many of the study results (Helmet laws) aren't popular with some parts of the MC community, the studies are being conducted.

Chapter 5 and Appendix 5 of this NHTSA report on countermeasures is good, but please read the detailed assessments in the Appendix to understand the evaluation of effectiveness. In many cases, it's a lack of definitive evaluations that result in the low score on effectiveness. https://www.nhtsa.gov/sites/nhtsa.d...k-a-highway-safety-countermeasures-guide-.pdf

Another good read is the annual report from the Governor's Highway Safety Association on motorcycle safety.
https://www.ghsa.org/sites/default/files/2018-05/ghsa_motorcyclists18.pdf

While both of these studies point to Helmet Laws as the most effective means of reducing fatalities, they also note the resistance of entrenched motorcyclist (political) groups, like ABATE & the AMA, which will prevent the enactment of these laws. Sadly the assessment of training programs to counterbalance the No-Helmet Law crowd is not promising. As noted in the federal register, the 2015 proposed rule for safety helmets acknowledges a significant number of riders choosing novelty helmets, even in states with mandatory helmet laws.
https://www.nhtsa.gov/sites/nhtsa.dot.gov/files/documents/2015-11756.pdf

Finally, the fine folks at the Center for Disease Control have also looked at the data and costs
https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6123a1.htm

wildbears said:

One way to reduce the "Coke Bottle" effect with a full face helmet is to use a "chin curtain".

These are available for many makes of helmets and are designed to reduce or eliminate the opening between the rider's chin and the "chin bar" of the helmet.

Below is an example of a Chin Curtain for the Shoei Neotec helmets. It slides in place between the shell and EPS liner on the bottom of the chin bar below the lower vent. It is constructed with a soft mesh material that allows some air circulation within the helmet for heat and moisture dissipation.

View attachment 77335

Other devices enclose the entire rider's neck at the helmet bottom. These may be more effective for wind noise reduction but can result in heat and moisture retention problems on helmets without sufficient shell ventilation.

Below is an example of the Windjammer product.

View attachment 77336

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Your interpretation of Dr. Kennedy's research has resulted in a very incorrect analogy, i.e., the Coke Bottle effect. At no point did Kennedy or other researchers claim the region behind the chin bar was functioning as a resonator with a distinctive, high energy tone. What he said was..paraphrasing.….the measured unsteady pressures under the front of the helmet correlated to the sound spectra (i.e., sound level vs frequency) measured at the riders ear. This was a significant contribution because many riders and acousticians would have assumed the dominant sources were the turbulent flows on the exterior of the helmet shell at the top (near the vents) or in the separated flow region at the back of the helmet.

The incorrect interpretation of the phenomena would lead one to investigate small changes in cavity throat area and volume behind the face shield / chin bar to eliminate or avoid the resonant condition with expectations of large sound level reductions. In a worse case scenario, let's call it the AMA/ABATE scenario, an unscrupulous, politically motivated person could make the extrapolation that no chin bar or face shield helmet would eliminate this resonant (Coke Bottle) condition.

What is severely lacking in this discussion is at-ear sound level measurements with various types of helmets at speed. As indicated by Kennedy's work, the helmet pitch angle (i.e., tilt) and position relative to the windscreen severely alter the flow field at the front and below the helmet (his last paper has smoke streak tests from the wind tunnel evaluations). Typically, changes in streak path curvature indicate high local velocities and noise level is a 4~6 power function of the maximum velocity (dB ~ V^4~6).

There are studies of the noise level reductions (i.e., insertion loss) for well-fitting full-coverage helmets which show significant sound level reductions at the high end of human hearing (8K Hz) but nothing at low frequencies (~125Hz). However, these tests were done stationary, in the same manner as any hearing protector test.