Sound Service Advice: Working Around Noise Laws

Koshollek noise laws exhausts law

IN THE LAST FEW YEARS, excessive motorcycle noise has been increasingly destructive to our sport's image. In response, we've seen municipalities across the country knee-jerking legislation into action that's taking all the fun out of riding. For example, in Carefree, Ariz., if you get busted a third time for a noisy motorcycle you can be slapped with a Class 1 misdemeanor that's punishable by a fine of up to $2,500, 180 days in jail and three years probation. An excessively noisy motorcycle in the not-so-carefree town of Carefree is determined by a less-than-consistent "drive-by" sound test that the city developed in-house.

In both Boston and Denver, attempts to snuff motorcycle noise are made not by measuring exhaust sound, but by visual inspection. To verify the Environmental Protection Agency's noise compliancy, verbiage is stamped into the muffler. Here, a cop can give you a ticket even when your bike is parked, ignition off!

But it's not just riders feeling the heat. I've heard of powersports dealers who were denied building permits because of the expected noise their business would bring to the area. When you've already purchased the land, this problem can be a financial disaster.


Whether you like loud pipes or not, realize that if you're not already experiencing pressure to reduce motorcycle noise in your community, you will. This is a huge concern to motorcycle manufacturers, the aftermarket and groups like the AMA, the MIC and the Motorcycle Riders Foundation. So, about six years ago the groups banded together to form the Motorcycle Sound Working Group. From this group came the 79-page booklet, "Sound Advice" that lists recommendations to address the problems caused by excessive motorcycle noise. Among the recommendations cited was the need for a roadside sound test that municipalities could use to identify offenders. This test, if adopted nationally, could reduce catastrophic legislation like that enacted in Boston and Denver.

The sound test suggestion spawned the creation of the MIC's SAE Motorcycle Technical Steering Committee. The main goal of the sound test was to identify excessively loud exhaust systems that were un-neighborly, not to outlaw all aftermarket exhausts as some have thought. The steering committee was made up of MIC's American V-Twin committee, member motorcycle manufacturers (including non-member Harley-Davidson), major parts and accessories distributors and yes, even 10 aftermarket exhaust manufacturers who wanted to take a proactive role in their destiny. The Society of Automotive Engineers was chosen as the certification entity because it's highly regarded for publishing accurate documentation and certification tests.

The MIC hired emissions consultant Tom Austin of Sierra Research to design the test. Austin is an avid motorcyclist and veteran "Iron Butt" competitor. To ensure they had enough data to satisfy the SAE's rigid requirements, Austin and his team tested 25 motorcycles, running a collection of both stock exhausts and 50 different aftermarket systems. The result was the SAE document J2825, the "Measurement of Exhaust Sound Pressure Levels of Stationary On-Highway Motorcycles," published in May 2009.

SAE J2825 details the test procedures, instrumentation, conditions and environment for the accurate measurement of motorcycle sound on stationary road-ridden motorcycles. J2825 describes how to properly administer the test so it's not adversely affected by nearby structures or vehicles that could amplify the sound or wind noise that could increase the overall measurement.

Three tests are described; Idle, Set RPM and Swept RPM. The idle test is performed first to weed out extreme offenders; it's also the easiest to perform by a single officer or vehicle inspector. SAE suggests a sound limit at idle of 92 dBA, which compares favorably to the EPA's current drive-by sound limit of 80 dBA.

If the inspector wants more data, they can perform a Set RPM test where the motorcycle is run at 2000 or 5000 RPMs (depending on the number of cylinders). All tests require the sound meter to be 20 inches from the muffler exit at a 45-degree angle to the line of travel. But enough about the technical details. If you want to perform the test yourself, you can purchase the J2825 test document from the SAE for $61.


It should make sense to those working in service to promote, sell and install either EPA-approved exhausts like the new BUB 7 Stealth mufflers, Harley-Davidson's Screamin' Eagle Street Legal mufflers or S&S's Stainless Performance Oval mufflers (all for Harley, BTW) to keep your customers on the right side of the law, or exhaust systems with idle volume close to stock. In the future, look for exhaust systems designed to pass the J2825 standard. Several exhaust manufacturers are developing products now.

If you service police motorcycles or you know someone in a political office, you can mention to these folks that an SAE-certified roadside sound test is now available. The more municipalities that adopt J2825, the greater the accuracy and fairness for identifying and dealing with the select few who run obnoxiously loud bikes. In turn, those of us with mildly massaged bikes will be better able to pursue a life of liberty and happiness in the world of modified motorcycling.

For more details on the sound issue, see the June 24, 2009 MIC press release, "Three Year Motorcycle Industry Council Effort Leads to New Roadside Sound Test," available at You can also view the "Sound Advice" booklet at