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Motorcycle sound levels: With new aftermarket products there's no reason race bikes have to be loud.

From the National Off-Highway Coordinating Committee (NOHVCC)

Things went surprisingly well at the legendary Jackhammer Enduro with the new California 96dBA sound limit in place. Many riders not only complied, but also added on a few extra "insurance" components to make sure they passed tech and started the race...With new aftermarket products there's no reason race bikes have to be loud.

"Be a hero yourself and get quiet. The future use of trails on public land depends on your action."

STONYFORD, CA - Something was different at this year's Jackhammer Enduro. Historically, dusty trails and loud dirt bikes were common occurrences at this popular event, which is part of the AMA District 36 2003 Moose B/C Enduro Club Series. Although the dust remained, the sound of loud bikes starting up in the campground at the crack of dawn in preparation for the day's ride was pleasantly absent.

On January 1, 2003 the new 96dBA sound limit for off-highway vehicles (OHVs) went into effect on all public lands in California. Last year at this enduro the sound limit was 101dBA. For every 3dBA reduction the human ear perceives the sound level cut in half. Team members from the FMF/BRC Sound Testing Program for OHVs provided courtesy sound checks on the day before the event. This allowed riders to get their exhaust systems checked so they could make pre-event adjustments (e.g. repack muffler, remove disks, add inserts, replace exhaust system, etc.) and avoid disqualification at the start line.

Representatives from the Colusa County Sheriff's department and the Mendocino National Forest were also on hand to help educate riders. The FMF/BRC crew also helped work approximately 200 motorcycles through the event's tech station.

Over 50 motorcycles were tested at Saturday's courtesy check and here are some test results;

  • 2003 Kawasaki KLX400 - FMF Q - 94.0 dBA
  • 2003 Yamaha WR450 - stock muffler with factory GYT-R tip - 90.5dBA
  • 2003 Honda CRF450 - FMF Q - 92.7 dBA
  • 2003 Honda XR650 - FMF Q - 90.9dBA
  • 2003 KTM 300EXC - FMF -Turbine Core II - 92dBA
  • 2002 Yamaha WR426 - stock muffler with ProMoto Billet insert - 91.1dBA.

It also seems that some riders are now buying "extra sound insurance." When open class 4-stroke owners opt to keep their stock silencers and upgrade them with a spark arrester/sound reduction end cap such as the Pro Moto Billet, they are wisely purchasing the additional "quiet tip insert." Since there is now enforcement for a "hard 96dBA" in California, smart dirt-bikers are making sure that they come in under the limit with several dBAs to spare.

Don Amador, western representative for the BlueRibbon Coalition, said, "Since the American Motorcyclist Association is going to a 96dBA limit for all of their non-closed course public lands events in 2004, I think it is important for riders to get their bikes into compliance with the new sound laws." "With the availability of high performance aftermarket exhaust systems such as the new FMF Q series or 'quiet tip' inserts for stock mufflers from Pro Moto Billet, Baja Designs and original equipment manufacturers, there is no reason for OHV owners to have loud bikes," Amador stated.

"If off-road hero, Malcolm Smith, and enduro-pro, Randy Hawkins, can operate motorcycles that are below 96dBA, then the average rider can do the same. Be a hero yourself and get quiet. The future use of trails on public land depends on your action," Amador concludes.

October 2003

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