Skeleton
New Member
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.
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.
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