Home
Basic Dirt Bike How-To's - Video
Dirt Bike How-To's - Video
Living The Moto Life - Video
Bike Tests | Shoot-Outs - Video
Forums
What's new
Latest activity
Log-In
Join
What's new
Menu
Log-In
Join
Navigation
Install the app
Install
More options
Close Menu
Forums
MX, SX & Off-Road Discussions
General Moto | Off-Topic Posts
Noise Problem: The AMA is a bunch of morons
Reply to thread
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Message
[QUOTE="Tony Eeds, post: 1174119, member: 32023"] Speedy ... you almost got there in class, but not quite. Check out a fellow named Chris Real, owner of [url=http://www.chemhelp.com/][u]Chemhelp[/u][/url]. He wrote the book on motorcycle sound and his partner wrote the test. dBA approximates the sound that is decernable by the human ear and it is a weighted scale. dBC treats all sound frequencies the same. It doesn't matter whether or not you can hear the sound, the meter still picks it up. It can be 3~5 dB higher on C scale than A. As Chili indicated the AMA, FIM, and everyone else for that matter, only use the tests published by SAE for motorcycles and ATVs and ISO for Full Size OHV. The SAE test number is J1287, and it is very specific about the procedure. It is designed to be a close proximity sound test for exhaust. Exhaust is the largest, but by far not the only, sound emitted by a bike. With the 20 inch rule, the procedure isolates the sound of the exhaust. The rule predated, by something like 10 years, the advent of the modern four stroke machine. To this point, notice I have not mentioned sound level. The AMA standard for closed course competition is currently 99 dBA and it is scheduled to decrease for competition machines to 96 dBA over the next few years. It is currently 96 dBA for enduros and the like. The Europeans long ago began dealing with this issue, but we Americans, many of which have little ..... syndrome, still want to believe that loud pipes mean more power. This is nearly always not the case, as bikes function best when the backpressure of the pipe matches the design specs of the engine. I trust Rich will correct me, if I am incorrect. The AMA does not get a lot of stuff, that goes without saying, but that is the discussion for another thread. I just returned from the NOHVCC conference and very few sessions happened without sound being brought up in the conversations. This is huge problem that must be dealt with. The accusation that Harley is behind the test criteria is a bit off base, but it is not off base to say that most people's opinion of motorcycle sound is more related to the sound they hear while sitting in their living room or their cage. They are against us and voice negative opinion, long before they are aware of what we are doing. BTW, Canada was well represented at the meeting. There were at least 3 provinces represented by 8~10 representatives. I will close with the comment that ATVs are 10 years behind motorcycles in getting it, so ... work on bubba. [/QUOTE]
Verification
Which ocean is California closest to?
Post reply
Forums
MX, SX & Off-Road Discussions
General Moto | Off-Topic Posts
Noise Problem: The AMA is a bunch of morons
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
Accept
Learn more…
Top
Bottom