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New SAE Motorcycle Exhaust Sound Test Standard

July 8, 2009 – The Society of Automotive Engineers (SAE) International has produced a simple, consistent and economical sound test standard that can be used to determine whether a street bike (on-highway motorcycle) exhaust system emits excessive sound, the American Motorcyclist Association (AMA) reports.

The J2825 “Measurement of Exhaust Sound Pressure Levels of Stationary On-Highway Motorcycles,” issued by the SAE in May, establishes instrumentation, test site, test conditions, procedures, measurements and sound level limits.  According to the SAE, the J2825 standard is based on a comprehensive study of a wide variety of on-highway motorcycles.

“The motorcycling community and law enforcement have long sought a practical field test for measuring street motorcycle exhaust sound,” said Ed Moreland, AMA vice president for government relations.

“Thanks to the hard work of the Motorcycle Industry Council, and the SAE engineers involved in the project, for the first time a simple field test is now available.”

“The AMA maintains that few factors contribute more to misunderstanding and prejudice against street riders than excessively noisy motorcycles,” Moreland continued.

“With the new SAE J2825 standard, street motorcyclists can now determine how quiet, or loud, their bikes really are.”

Moreland added that the new standard follows a template established years ago with the SAE J1287 off-highway motorcycle sound test, a standard recommended by the AMA wherever off-highway motorcycles are operated.

The SAE J2825 on-highway motorcycle sound test procedure is similar to the one used for the SAE J1287 off-highway motorcycle test.  The street bike measurement requires holding a calibrated sound meter at a 45-degree angle 20 inches from the exhaust pipe of a running engine.

The procedure spells out how to do the test with the bike at idle, at a predetermined engine speed (“Set RPM Test”), or by slowly increasing the engine speed of the bike, known as the “Swept RPM Test.”

The SAE J2825 standard, prepared by the SAE Motorcycle Technical Steering Committee, recommends a decibel limit of 92 dBA at idle for all machines; or, using the Set RPM or Swept RPM Test, 100 dBA for three- or four-cylinder machines, and 96 dBA for bikes with fewer than three or more than four cylinders.

The creation of a new street motorcycle sound measurement procedure was a top recommendation of the 2003 National Summit on Motorcycle Sound, expressed by its Motorcycle Sound Working Group.

The AMA organized the National Summit on Motorcycle Sound to pull together riders and user organizations, representatives of the motorcycle manufacturers, the aftermarket industry, racing promoters, government agencies, and others to develop proposals regarding the increasingly controversial issue of excessive motorcycle sound.

“The J2825 test allows jurisdictions around the nation, struggling with complaints about excessive motorcycle sound, to set reasonable limits in accordance with the SAE standard,” said Moreland.

“While the AMA supports the establishment of the SAE J2825 standard in America’s cities, towns and communities, we will continue to fight efforts that single out motorcycles while still permitting excessive sound from other sources, such as loud cars and trucks, booming car stereos, poorly maintained generators, whining leaf blowers, and the like.”

The SAE J2825 standard can be downloaded on the SAE website for a fee.

More:  wBW Motorcycle Exhaust Systems Page

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From “KdK” (7/09):  “I’d like to say I’m against anything that limits my freedoms so I already have a negative opinion about this document and AMA’s support of it.

The noise my bike makes last only for seconds for bystanders but I have to live with it for as long as I’m on the bike.  It doesn’t make sense to me to have the government tell me what I can listen to when it only affects others for a very short amount of time.  If someone was revving their engine in a neighborhood for 30 minutes at 11 PM – maybe.

But driving by on the highway or through town to get home?  Leave me alone and let me enjoy the ride.  It isn’t like Rolling Thunder is going through every town every day.

In the article it says:

“The SAE J2825 standard, prepared by the SAE Motorcycle Technical Steering Committee, recommends a decibel limit of 92 dBA at idle for all machines; or, using the Set RPM or Swept RPM Test, 100 dBA for three- or four-cylinder machines, and 96 dBA for bikes with fewer than three or more than four cylinders.”

I don’t understand why the sound level can be higher for 3 and 4 cylinder bikes than it can be for 2 and 6 cylinder bikes.  Maybe the answer is in the SAE document but I won’t pay $61.00 to read it.

This brings up another point.  Can a municipality build a law (or standards used for a law) around a document that we have to pay to read so we understand our (loss of) rights?

Maybe the AMA should spend a little more time working for bikers rights instead of bikers restrictions.”

Editor’s Reply:  Just for the record, the article is a press release about a new standard for testing sound levels.  We have no opinion on the politics of the topic one way or the other at this point, it is just an article of interest.

However, by way of explanation:

It’s my understanding that the AMA worked with SAE to develop the standard because:

1) There was no standard, accepted and accurate method to test motorcycle exhaust sound, so what was valid in one state was not valid in another;

2) A standard test will help eliminate the subjectivity that many state and local agencies used; e.g., “that motorcycle sounds loud, I’m giving you a ticket”; and

3) Because the states and localities were pushing for legislation that might end up being more unreasonable than motorcycle owners or the industry wanted, so it was a proactive move to at least develop a standard and get it out there, rather than waiting for a standard to be legislated and implemented as a done deal without any AMA or other motorcycle organization’s support.

Regarding your question on paying for the copies of standards:  Since the SAE is a private organization, yes, they can and do charge for copies of this and any other standard.

In fact, almost every standards organization throughout the world in various countries that have them charge for copies of the actual standard, which is how the standards organizations earn revenue to support the engineers, scientists, etc. that develop the tests and standards and monitor the results, if required.

So, as you can see, there’s a lot more to this entire topic than just the AMA or the government coming down on motorcyclists…