Making for a QUIETER ride (screen and helmet)

[Skeleton]

This thread is about how I have made my ride quieter by:

1) using an alternate arrangement for a laminar lip on a stock short screen, and
2) enhancing a quality helmet with a foam neck collar.


MY TOUR

I recently came back from a 5 day ride, covering 2400 km. This took me mostly through mountain regions of eastern British Columbia (Rocky mtns) and Northern Washington state (Cascade mtns). While the ride was spectacular, I continually suffered from mental fatigue from enduring aggravating wind noise.

The bike is a NC750-S (2014), fitted with a CalSci tall windscreen; atop the screen was a Winderlich screen spoiler (deflector) positioned in a vertical posture - to make an even taller screen. My helmet was a BMW System-7 modular flip-up helmet (made by Schuberth). I was riding between 95 kph to 130 kph, with an common speed of 110 kph. The weather was sunny with either no winds or only light breeze.


OBSERVATIONS

The tall screen was only effective if I would crouch forward so that my entire helmet was shielded by the windscreen. Nonetheless, there was still some noise that perpetuated my fatigue. Occasionally I did some tests while riding. I tried various positions of the screen spoiler with only little improvement. The least noise occurred when I would STAND up while riding down the highway (only for ten seconds for testing purpose); there the air was perfectly undisturbed and clean. This standing posture was quieter than when crouching behind the screen.


CONCLUSIONS

Air trailing from the edge of a screen always proceeds horizontally. It never takes a curved path upwards despite coming off of a screen and/or spoiler that was canted on a vertical slope.

Tall screens are not very quiet if they are narrow (such as CalSci). This is because the trailing air can quickly close into the lee-side of the screen and flood the region with turbulent mixed air. The only way for a tall screen to be quiet is if it is also very wide (such as on full touring bikes and many highway cruisers).


RESEARCH

I have since researched the cause of noise as experienced by motorcyclists. Most of the research was based on scientific literature or on interviews with engineering staff for helmet companies (Shoei, Arai, Schuberth). Following are the highlights of the research:

- Much noise heard by a rider originates from turbulent air underneath the chin bar of the helmet (where the rider's neck is).

- Tight fitting helmet (chin pads press firmly against head) makes a significant reduction in noise.

- Only large windscreens (tall and wide) can shield the rider from wind noise. Otherwise, often no windscreen (or very short) can allow quieter wind noise because of the cleanness of the air flow.


REFERENCES

https://www.youtube.com/watch?v=G7eSiIOQ02g
https://www.youtube.com/watch?v=r166Lbygbc4
https://www.youtube.com/watch?v=vvsNSoEU710
https://www.youtube.com/watch?v=Hq72PNG1100
http://benthamopen.com/toacoj/articles/V004/14TOACOJ.pdf
http://www.insidescience.org/content/lowering-volume-motorcyclists/714


MY SOLUTION

- Purchased Shoei GT-Air helmet, highly regarded as one of the quietest helmets. Both the manufacturer and reviewers attest the quietness to the tight fitting of the helmet to the rider's head. My personal testing confirmed this.

- Added high density foam to the speaker cavity of the Shoei helmet. The foam was merely a foam insole from regular running shoes, cut to suit the speaker insert cavity.

- Made a neck collar; constructed of a long chunk of foam cut to suit, and fitted inside a neck muff.

- (Continue to wear quality ear plugs.)

- Discarded my semi-tall after-market windscreen (CalSci). It is too narrow to be effective; the narrowness is a limitation imposed by the bike's mounting bracket.

- Reinstalled the short stock windscreen (Honda). Added the Winderlich air spoiler; adjusted its attitude to be perfectly horizontal. This configuration serves to redirect pressured air coming off and above the stock screen to below the deflector. As such, the air above the deflector will be predominantly clean air. Further above, where the rider's ear are, the on-coming air will be clean.


MY RESULTS

The foam neck collar had a huge improvement; this easily reduced the noise by some -10 dB. Easy to test: ride at highway speed with collar one, then reach up and pull the collar away or down from neck - instantly the wind noise becomes much louder.

The spoiler/deflector kept the air very clean above the projected horizontal line. There was no difference in noise level from sitting to standing posture with this deflector posture.

The quality, tight-fitting one-piece helmet is noticeably quieter than my previous modular flip-up helmet. The small foam inserts that I added reduced the air movement in the ear cavity of the helmet.

 

[Cigar Mike]

I had come to the same conclusion about the air coming in from under the hemet. Using the Sena SMH10s the mics will pick up the noise if not positioned correctly. Not all windshields are the same. I have had good results with the CeeBailey shields. The one I had on my FJR pretty much removed the wind. The CB shield on the nc does move the air over my head and there is no air hitting me from over the top. That riding position handle bar location does not allow a shield design to be 100% effective. The air that moves around the shield at the handlebar cutouts allows the air to hit your torso and come up into the helmet from underneath. I was thinking about trying a tube type sleeve from around the neck and stretch it over the bottom edge of the helmet.

 

[Bullseye]

Skeleton,

SIDE NOTE **** I too had "Ventrua Luggage System" on my old CBR !!! I love it , work great...most of the time didn't even feel it behind me. And man could I pack alot into those bags !!!. I went with "Honda" Luggage for my NC700x.

P.S. Good pics too !!!

 

[mreric]

i dont know if you read one of my post,, but a lot of the noise came from mirror of the NC. i replaced the mirror and lot of the noise went away.

if you have had other motorcycle. i have concluded that the NC just has lots of edges that create lots of turbulence and noise. - i actually have crossed my mind to sell the NC but am still in the process of a remedy for it.

I have a FZ-07 yamaha and is completely different. very clean air and very comfortable compared to the NC.

I have a Rpha max helmet rated at 84 DB


remove your mirror and go for a ride. it made a difference for me., it might or might not for you based on your height in relationship to the mirror

 

[caldercay]

Thanks for the posting.

Here's RideApart's Five Quietest Helmets article.

I really wanted a C3 Pro, but the Large was too small and the XLarge was too big. I've tried Arai's and Shoe's, but they both don't quite fit my style of head. The RPHA-10 (Large) fits like a glove and provides ample wind protection with comfort. It's not on RideApart's list, but its sibling, the RPHA Max (flip up) is, which I intend to get within the next month. Flip-ups are surprisingly quieter, as they can pack more padding around the lower perimeter of the helmet.

On Page 1 of the RideApart article, there is mention of the WindJammer 2 sleeve. It fits around the lower perimeter of the helmet and neck, blocking the wind flow into the helmet.

 

[itlives]

Good post, Skeleton.

I was told by my dealer that most modular helmets are fairly loud. I have a HJC CJ-16 with a Puig Touring screen and visor (they are narrow). Works good for my frame.Every body is different. I wouldn't want to put a collar on in the summer in Louisiana!

 

[caldercay]

I wouldn't want to put a collar on in the summer in Louisiana!

The WindJammer mentioned in the article I posted above is a good option to a large "collar".

But yea, Louisiana or Texas this time of year - no way I want more gear.

Just checked Vancouver's weather for the next 10 days: 68, 66, 72, 76, 79, 80, 80, 69, 70, 71 (humidity averaging 60%)
In Texas, we wont see that until November (and our humidity will be at least 80%)

 

[Skeleton]

Good post, Skeleton.

I wouldn't want to put a collar on in the summer in Louisiana!

Agree. The collar does make for a warmer ride.

I found that when speeds get over 80 kph (highway) then the noise is too aggrevating. My intention is only to ride with the foam collar on highways where the higher speeds are too noisy for my comfort. On the highway, the higher wind speed can compensate for the heat of the collar. I found (IMHO) that city speeds (60 kph) would not create loud noise, so no collar would be needed for me.

 

[Skeleton]

Thanks for the posting.

Here's RideApart's Five Quietest Helmets article.

I really wanted a C3 Pro, but the Large was too small and the XLarge was too big. ...

On Page 1 of the RideApart article, there is mention of the WindJammer 2 sleeve. It fits around the lower perimeter of the helmet and neck, blocking the wind flow into the helmet.

Yes, a good (tight) fit can mitigate the noise immensely. My HJC Sy-Max helmet is now 6 years old; the foam has compressed resulting in a looser fit that has become noisy. My BMW System-7 (Schuberth), now 3 years old, still fits snugly but its hinged flip-up does allow some noise to enter the ear cavity of the helmet. I credit the quietness of my new Shoei GT-Air to its overly tight fit.

My doubts about the Windjammer is that it is a thin neoprene membrane. I believe that the membrane could allow noise from any turbulent air which passes by the outside face of the Windjammer (under the rider's chin) could transmit through the semi-dense material. Refer to following test article. Note: the frequency range for wind noise for riders is mostly below 500 Hz.

http://archive.rubicon-foundation.org/xmlui/handle/123456789/1515

Tukey's HSD post hoc analysis showed significant decreases in wetsuit hood sound attenuation with increasing depth only for frequencies from 500 to 1500 Hz (p less than 0.05). For frequencies below 500 Hz there was virtually no sound attenuation.

In contrast, the neck foam collar is about 2-inch thick, for which noise on the outside face would be attenuated much more before reaching the ear cavity of the helmet.

However, the Windjammer could be a better solution over the foam collar in hot climates.

 

[showkey]

I wouldn't want to put a collar on in the summer in Louisiana!

+2 in Wisconsin........90 degrees is 90 degrees..........but very soon heated gear will be coming out of storage.