Cycle News
Motorcycle Noise Study

Email Notice Received 08/10/2006

 

Subject: [Cycle_News] AIM/NCOM MOTORCYCLE E-NEWS SERVICE: MOTORCYCLE
NOISESTUDY

AIM/NCOM MOTORCYCLE E-NEWS SERVICE: MOTORCYCLE NOISE STUDY

OUR AIM/NCOM MOTORCYCLE E-NEWS SERVICE RECENTLY RECEIVED THE FOLLOWING 
INFORMATION FROM KEITH "BANDIT" BALL, FORMER EDITOR OF EASYRIDERS 
MAGAZINE AND FOUNDER OF BIKERNET.COM, AND IN THE INTEREST OF BIKERS 
RIGHTS AND IN RECOGNITION OF THE GROWING TREND OF LEGISLATING AND 
REGULATING MOTORCYCLE EXHAUST SOUND LEVELS, WE ARE PLEASED TO PASS 
THIS ON TO ALL FREEDOM FIGHTERS, MOTORCYCLE RIGHTS ORGANIZATIONS, AND 
MOTORCYCLE PUBLICATIONS:

I recently was hit by Noise Freak efforts, and it scared me that in a 
noisy world bikers would take the brunt of their silencing efforts. 
Even the AMA suggested that we cower and hide to prevent future 
intrusions into our rights. A respected Motorcycle mag editor said 
this to me, in defense of his notion to be quiet and maybe they'll go 
away: "I think if our pipes exceed an acceptable level (whatever that 
means), and we continue to make people (non-riders) hate us, we will 
reap whatever 'rewards' they want to heap upon us." I disagree. We 
must stand and fight for our rights or deserve to get our asses beat.

I've run this concept and notions by NCOM, the MRF, ABATE, SEMA 
representatives, a senator and now I'm releasing it. They all 
applauded the notion. Freedom fighters across the country believe 
strongly, that we must stay right in the face of legislators, that if 
we acquiesce or try to hide, we'll be toast, quick. One guy said, 
"We're the Indians now. We need to keep up the fight."

If we can create the first platform for this and create a ground-swell 
of activity, we can hopefully accomplish the following:
Additional testing and implementation by higher ups
Continued motorcycle freedom
Heightened motorcycle awareness and respect
Maybe save some lives
Keep the bastards off our backs

Feel free to drop me a line and let me know your thoughts,

Ride Forever,
Bandit
bandit@bikernet.com
 


BIKERNET.COM INDEPENDENT MOTORCYCLE NOISE STUDY

In a world of increased levels of constant noise and heightened 
efforts to curb excessive decibel levels motorcycles take a hit. 
Bikernet.com, the world's largest website in the custom motorcycle 
industry, sought to study motorcycle noise against constant 
environmental disturbances and put the motorcycle exhaust sound into 
proper perspective.

Motorcycles are unique in that they are the least pervasive of all 
vehicles jammed onto our roads today. They have the least protection 
and the best mpg ratings of all vehicles. We noted the obvious, 
motorcycles lack bumpers, airbags, double-wall doors or steel 
ceilings, yet take up 1/3 of the space of common sedans, and are more 
agile than trucks or compacts in avoiding dangerous situations. 
Motorcycles have but two defensive measures to enhance their agility; 
visual and auditory awareness. For decades motorists have used the 
excuse that they are unable to see a narrow motorcycle, so it's okay 
to hit one. State legislators are currently dealing with that fallacy.

Yet, still between 70 and 85 percent of all motorcycle/motor vehicle 
accidents are caused by motorists. Plus, the use of cell phones, GPS 
screens, DVDs, CD players and other major distractions are increasing 
the need for motorcycle awareness.

Recent statistics indicate that over 80 percent of motor vehicle 
accidents happened while the driver is distracted by cell phones, 
eating or other interruptions.

Much like emergency vehicles, the sound a motorcycle makes is critical 
to its ability to alert motorists of its whereabouts. That became our 
study criteria and we tested four motorcycles to determine an 
acceptable decibel level to allow a motorcyclist to be heard. We also 
discovered a recent court case that demonstrated this contention.  
woman testified she was unaware of the presence of a motorcycle. Sound 
testing proved her a liar. We measured the decibel levels from 2 feet 
away from the open end of the muffler at 45 degrees. We also 
discovered that some states measure decibel levels from as far as 50 
feet away. In that case every motorcycle tested emitted less noise 
than most 18-wheelers.

2003 Harley-Davidson Road King Classic, 1,400cc with mild 
modifications and a full Screamin' Eagle 2-into-1 Exhaust System:
100 decibels at idle
108 decibels at cruising throttle
116 decibels fully revved.

2004 1200 cc Sportster with full aftermarket Samson 2-into-1 Exhaust
system:
100 decibles at idle
108 decibels at moderate rpms
120 decibels fully revved.

Custom 1956 Harley-Davidson, 1488 cc, with custom 2-into-2 exhaust 
system with modified shorty mufflers:
102 decibels at idle
111 decibels at cruising speeds
124 decibels revved

2006 Softail Standard 1,400 cc, original from the factory:
97 decibels at idle
102 decibels at cruising speed
111 decibels revved

For reference, we measured the noise levels of cars and trucks passing 
our meter at between 35-45 mph at 10-50 feet distance. Passenger 
vehicles ranged in the 78-83 decibel range whereas trucks ranged from 
90-100 at that distance.

We took each one of these motorcycles and tested them in three traffic 
scenarios.

Passing: Wherein a motorcycle approached a passenger vehicle with 
windows rolled up and radio playing (and without). We tested the 
approach from both sides of the car.

Oncoming Intersection Scenario: Again we used a late model passenger 
vehicle with the windows rolled up a radio playing (and without). This 
time both vehicles approached an intersection and we determined if the 
motorcycle could be heard across an intersection in this test vehicle.

Cross Traffic: Again we tested whether a motorcycle can be heard 
closing on an intersection from a right angle from the oncoming 
vehicle approaching an intersection, when a building exists on the 
right hand corner.

We discovered that the stock motorcycle could not be heard in the 
passing test unless the motorcycle was along side a moving vehicle. If 
a radio was playing at 80 decibels within the vehicle the motorcycle 
would be nearly undetectable. A dangerous situation for a motorcycle 
that takes up limited mirror viewing area.

We discovered that with a radio playing the Sportster could be heard 
at just one car length behind the vehicle. The results were almost the 
same for the Road King.

With the radio off, these motorcycles could be discerned at two car 
lengths. A brief span of time in traffic to maneuver if a car altered 
its direction abruptly.

The custom bike could be easily detected following at 5 car lengths 
and close to 7 if the radio was not in the equation.

The intersection test was the most difficult because speed and 
distance are tricky to determine control. The un-altered 
Harley-Davidson was difficult to hear at all with or without radio 
interference.

The modified Road King and Sportsters had a fleeting chance of being 
heard across an intersection to warn a motorist. The only motorcycle 
that could be easily heard across an intersection was the 1956 Custom 
with modified exhaust.

The final test was most interesting. Again the stock bike would 
virtually arrive at the intersection unheard, whereas the Sportster 
and the Road King were detected for 3 car lengths before the 
intersection. Consequently there would be a moment of driver reaction 
time available, at 35 mph, for the driver or motorcyclist to react to 
a dangerous situation.

Again the custom bike with modified exhaust could be heard from over a 
block away prior to the intersection allowing the driver to be aware 
of an approaching motorcycle and make defensive maneuvers prior to 
entering the intersection.

Our study also identified the consistency of road sound in an 
industrial area in Wilmington, California, which affords almost year 
around riding weather. This street has an average of 450 trucks 
passing in an hour given at 93-100 decibels. An average of 673 cars 
pass daily during a peak hour at a constant 81-83 decibels and maybe a 
dozen motorcycles pass by during that hour for a culminated seconds of 
motorcycle noise at 80-100 decibels.

Our findings point out various considerations regarding motorcycle 
noise regulations. We are not in favor of disturbing or irresponsible 
motorcycle noise. We support Daytona, Florida's anti-revving 
ordinance. Abusive noise use is ticketed. We also support an ordinance 
that allows ticketing for any motorcyclist who abuses his motorcycle 
after 10:00 p.m. at night in a residential district. We believe that 
motorcycles need to make some noise, but that it must be handled 
responsibly.