Noise Problem: The AMA is a bunch of morons


SpeedyManiac

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Aug 8, 2000
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Hi guys,
As most of you know, I'm in Mechanical Engineering at the University of Alberta. Well, in my vibrations class we are also covering sound. Today in class, we talked about sound pressure levels, sound power levels and the different scales used to correct for frequency range. The idea of the scale correction is to account for the ear's ability to pick up frequencies around 3100Hz better than other frequencies. In essence, it is a perceived loudness correction.

There are four correction scales used today: A, B, C and D. A is the most common, widely accepted scale. C is still used a little bit and B and D are close to extinct, though they still exist. I don't have the graph handy (I'll ask my professor for a copy) but in essence, the 'A' scale reduces the sound rating of lower frequency sounds. Sometimes by as much as 20dB. The 'C' scale weights all frequencies close to the same. Guess which scale the AMA uses.

That's right, the AMA uses the dB(A) scale, which underrates low frequency noise. What frequencies do four-strokes make noise at? Anyone? That's right, lower frequencies. So, while a two-stroke and four-stroke might 'test' the same on a 'A' scale measurement system, in essence, the four-stroke is actually louder in absolute sound pressure level. No wonder there is noise complaints. What a bunch of idiots the AMA is.

I want to know if they actually consulted any professionals in the sound industry, or if they did any research? I have a grasp of this stuff after two 50 minute lectures on the material. Someone who's livelihood depends on this stuff should know what's going on. What a bunch of idiots... :bang:
 

kmccune

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Welcome to the anti-AMA fan club.
 

bsmith

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Welcome to "how to make Harleys quiet; without making Harleys quiet" :whoa:
 

Patman

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bsmith said:
Welcome to "how to make Harleys quiet; without making Harleys quiet" :whoa:
Silly, don't you know if you make Harley's quiet then they are completly worthless?! Just like those silly little party blower things if you take the noise maker off then it's just a tube of worthless paper.
 

thorman75

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I've said this before, my Wideglide is running 2" dragpipes and my Ultra Classic has a Python system. Loud pipes save lives. How about a bunch of crack heads in a Caddy with all the windows rolled up and a 500 watt stereo booming. Dont complain about my exhaust.
Yeah the FXWG is louder than the KX, but I can still hear the straight cut gears on the Maico whineing above both of them.LOL
 

thorman75

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Patman said:
Silly, don't you know if you make Harley's quiet then they are completly worthless?! Just like those silly little party blower things if you take the noise maker off then it's just a tube of worthless paper.
Patman where you livin, stop by NW Indiana and I'll let you see for yourself how worthless those HD's are.
BTW are you married? Ahh never mind these women don't care if you are.
It's funny when I'm leaving school(I.U./N) and I'm on the bike there are always one of my coed's wanting to go for a ride.And I understand, but you don't, when they get on the back 5 miles down the road theyre all BAD girls.he he he :)
 

Patman

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There is no point to them except to be an "American Icon" so aparently they need to be loud to justify existing as a slow, heavy, stone age vibrating pig. If they were anything but a noise maker (which like every other noise making device from the little party blowers to fire works) you would see them on the track competing against other brands. Does HD have a dirt bike? GP/road race bike? :think: not that I see in their current linup. Why? See above.

Since I don't have the need to draw attention to myself they are as I stated worthless to me, same as the mega high wattage sound systems. Do I see these types of things where I live? Sure, I even work with a few guys that ride HD's with pipes and they do nothing but prove up my point. They NEED the attention because they have other issues that are very aparent to everyone.
 

bsmith

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It's like the guy with the Short Box, Crew Cab, 35's, 6 inches of lift, full chrome package, big bumper, and a Diesel with 5 inch straight pipe.

Hmm, let me think the chrome package negates the mud tires, the lift kit negates pulling anything, if your not pulling you really don't need a Diesel, and a short box you can't haul jack with, and the pipe is just for noise so people will turn and look :nener:
 

thorman75

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Ive been riding now for 45 years.The HD is what it is and thats all. The saying is "If I have to explain it you probably woundn't understand".
There are other venues besides who's the fastest.
If I was wanting to go fast on a bike I'd buy a ZX11. But I've been there and done that, don't want to do it again.
The local HD shop told me last week that they have sold 53 units so far this year Hummmm.Seems other people like them too.53X 18,000.00(AVG) = 1,000,000 in sales
kind of hard to snub your nose at that, thats alot of Americans working
 

thorman75

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bsmith said:
It's like the guy with the Short Box, Crew Cab, 35's, 6 inches of lift, full chrome package, big bumper, and a Diesel with 5 inch straight pipe.

Hmm, let me think the chrome package negates the mud tires, the lift kit negates pulling anything, if your not pulling you really don't need a Diesel, and a short box you can't haul jack with, and the pipe is just for noise so people will turn and look :nener:
Or the guy that walks into the Honda shop and needs a PC pipe,Ti Valves And E gorr porting on his new CRF450 so he can ride "C" class,goes home to armorall his knobbies
 

kmccune

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OK children, we were bitching about the AMA....
 

Patman

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No explinations necessary, they typically only confirm the obvious anyway :laugh:

Working Americans is great, I don't believe there is any argument there. Of course Americans also build Honda, Toyota, & BMW products as well but that's one of theose obvious explination things I guess.

Heck accessories are a big money maker for most dealers, nothing wrong with selling the customer what he wants. It's a free country and people can make their own choices. I suspect the guy that blings out his CRF450 (Ti valves stock I believe) is very much like they person that "needs" loud pipes. It's a feel good thing, everybody wants to feel good about themselves, some people need attention to to do that and others are self assured enough that they don't.

AMA? We don't need to stinkin' AMA!!!
 

IndyMX

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Patman said:
There is no point to them except to be an "American Icon" so aparently they need to be loud to justify existing as a slow, heavy, stone age vibrating pig. If they were anything but a noise maker (which like every other noise making device from the little party blowers to fire works) you would see them on the track competing against other brands. Does HD have a dirt bike?

Here's one that might not fit your rant..

Not that I give to nickels about HD street bikes, or any street bike at all.
 

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bsmith

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accessories are a big money maker for most dealers

My father in law is a big Harley guy, and I had to sit at the dealership last Thanksgiving while he order accessories for his wifes new bike! $5,000k later we got to leave!

But they go on long multi week trips, that I want to do when I'm older and after I can no longer do Adventure tours ;)
 

bsmith

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I got it! Instead of global warming credits like Al Gore buys, we can start selling "Noise credits"

If you put a Suzy Q quite muffler on your bike, you get a noise credit you can inturn sell to the AMA who can then sell to someone with a Harley or track owner! :cool:
 

JPIVEY

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Oh Harley Shmarley, built two customs and trophied one of them, also bought one from a dealer, they're over rated

now, a Kettenburg 50 or Formsa 51, now thats a work of art, although not real good in the dirt :nener:
 

DougRoost

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BTW are you married? Ahh never mind these women don't care if you are.
It's funny when I'm leaving school(I.U./N) and I'm on the bike there are always one of my coed's wanting to go for a ride.And I understand, but you don't, when they get on the back 5 miles down the road theyre all BAD girls.he he he :)

I get what you mean. Even my wife, who's not real happy that I ride motorcycles because of the danger factor, was digging that Harley after she got a quick tour around our neighborhood from a friend on one. And this one wasn't loud, just the aforementioned vibration and wind in the face.

Doug
 

Philip

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That's not really fair Patman. I ride a HD which is posted somewhere on here and a CRF450. The 450 is louder than the HD, so are you saying that I am trying to draw attention to myself when on the track. If you knew me you would know I putt around and never, on either bike, need to draw attention to myself. I am sure you don't mean all HD people are this way just the ones you work with. :p

If its got two wheels I like to ride it. It is great time spent together with my son and the best stress relief you can find. When was the last time you saw a Harley parked in front of a Pschiatrist (sp?) office. :laugh:
 

bsmith

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Yes and Yes :)

We have also learned Philip will ride anything with 2 wheels, we should sell noise credits, Patman is jealous he doesn't have a Harley, Thorman is proud he has one, and that you should always wear a helmet, even when on a moped;

http://www.lovethatfun.com/Fat_Dude_Crashing_on_Moped/1426/
:laugh:
 

Chili

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Im not certain but I was under the impression the AMA simply adopted the testing method set forth by the FIM? (Trying to help you recover from the thread jacking speedy :) )
 

Tony Eeds

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SpeedyManiac said:
Did any of you guys actually read and understand my original post? Or am I just talking to myself?

Speedy ... you almost got there in class, but not quite.

Check out a fellow named Chris Real, owner of Chemhelp. 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.
 

SpeedyManiac

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They may have adopted it, but there is a fundamental flaw in their testing that will give the four-strokes an unfair advantage in noise testing. I'm trying to get a couple charts from my professor that will help explain the concept clearer.

Basically, if I'm correct, four-strokes that test the same as a two-stroke could (unlikely, probably much less like what Tony said above me) be as much as 20dB (uncorrected, absolute pressure level) louder than a two-stroke tested at the same 'corrected' level on the dB(A) scale.
 


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