Shhhhhhhhh!...let's keep it down out there!

Status
Not open for further replies.
Joined
Nov 14, 1999
Messages
125
Likes
0
#1
Let me get this outta the way right now. I like the sound of a fire-breathing thumper with the throttle pinned WFO. But I, along with everyone who shares my likes had better start doing they're part to reverse this trend of un-godly loud aftermarket exhaust systems and get used to quieter systems.

Go to www.motorcycledaily.com for some insight on this topic and how it relates to the publics perception of us.

Db's are going to be more important to me than h.p.'s while shopping for my next system.

Thump on!
 
Joined
Nov 14, 1999
Messages
125
Likes
0
#3
97db? Thats pretty loud. To me though, thats just about right...no earplugs needed.

However, if we want to keep riding areas open, we have to be more concerned with what the opponents consider offensive. I'm gonna aim for 92 dbs or less. Stroker has a turndowned insert for my WR250 muffler but doesn't state how much reduction it provides. I dropped em' an email to find out yesterday. I will let ya know how it goes.

The FMF powerbomb with the stock muffler is supposed to suppress a little also and if they're h.p. claims are accurate, I may try one.

Thump on!

[This message has been edited by Buckwheat816 (edited 02-28-2001).]
 

Neil Wig

Lifetime Sponsor
Joined
Jun 22, 2000
Messages
347
Likes
0
#4
Keep in mind that dB measurements are a logarithmic scale. This means that for every gain of 6 dB, the sound energy doubles. So, 97 dB is almost 1/2 the sound energy of 100 dB. I don't have any test data to back this up, but I would suspect the sound energy to be the driving factor when considering how far the sound will travel (and how many people will be bothered by that sound). So, when you see a "modest" increase in sound level of 2 or 3 dB, it is equivelant to 30% to 50% more sound energy.

Later
Shhhhhhhh.
 
Joined
Jul 27, 1999
Messages
22,652
Likes
466
Location
Chicago
#5
Neil is right. The db reading can be misleading, and it doesn't address frequency. Peoples annoyance level has as much to do with the frequency of sounds as it does with amplitude/volume. So db is just part of the problem

As an example of Neil's point, OSHA provides a list of how long you can expose your ears to a specific volume before damage occurs.

90 dB A 8 hrs.
95 dB A 4 hrs.
100 dB A 2 hrs.
105 db A 1 hr.
110 db A 30 min.
115 dB A 15 min.
120 dB A HUHHH?????????????
 

Jonala

Subscriber
Joined
Sep 20, 2000
Messages
564
Likes
0
#6
Buckwheat,

I've been doing experiments on a 2001 XR 250. I've made custom inserts that fit into the tail section to the muffler.

My results showed that a insert that had a down turned pipe made no difference on my dB meter. The bike did "sound" quieter. I was surpised with that result.

I would be interested in seeing what response you get from Stroker.
 

BadgerMan

Mi. Trail Riders
Joined
Jan 1, 2001
Messages
2,479
Likes
7
#7
That’s a true story.

I have done testing of small electric motors in a sound proof environment and you can have two motors that both pass the max db spec but they will sound very different and one may even sound substantially “louder”. You have to do an analysis of the entire frequency spectrum to get the true picture. I don’t know much about db meters but IMO, they are a fairly crude measurement tool with a high R&R percentage. I do know (based on experience with different bikes) that four strokes are easier to get through an enduro sound check. I have heard two theories on this:

1. Older guys, like me, run sound checks and they like the sound of four strokes! LOL!
2. Db meters are “more forgiving” of the frequencies that four strokes typically emit.

I am not sure which to believe but I do know that sound pressure levels of varying or mixed frequency are tough to accurately measure in a repeatable manner.
 

Vic

***** freak.
Joined
May 5, 2000
Messages
4,008
Likes
0
#8
It would seem that the real solution to this problem would come from noise cancellation technology. Does anyone know enough about this to comment on whether or not it could be feasibly applied to dirt bikes?
 
Joined
Feb 28, 2000
Messages
68
Likes
0
#9
A paved, oval racetrack sits abandoned with pine trees growing through the track, infield, and metal bleachers less than a mile from my house. The track ended up in the city limits due to annexation. While the city council could find no legal means to shut down the track, the community petitioned them to shut down the track, primarily because of noise complaints. A resolution was passed prohibiting the sale of alcoholic beverages which apparently made the track unprofitable and it has never re-opened.
If you will notice from my address, this occured in the deep south. If the people down here will not tolerate this type of noise, the rest of you in other parts of the country haven't got a prayer.
If you can run a load exhaust only on private land and change to the stock exhaust when on more sensitive riding areas, I commend you on your behavior. In my experience, riders tend to lose patience with changing the exhaust, and the loud one is usually left on the bike.
Dirt bike riders are an extremely small percentage of the population; the rest care very little of our effort to perserve off-road riding. We can jump up and down screaming about out rights to make noise. Just as your right to freely swing your arms and fists ends at my nose; our right to make noise ends at someone's eardrum.
I am astounded that some dirt bike riders are so politically naive that they cannot understand the other 99% of the voting population and what our less than 1% has to lose.
 

Rodzilla

Lifetime Sponsor
Joined
Jul 21, 1999
Messages
615
Likes
0
#10
Well obviously I'm not a sound engineer but I think part of the problem is with the nature of the sound being emitted by our thumpers compared to the two strokes.

Folks are saying the new thumpers are too loud (they are) as opposed to 2-strokes (also too loud).

The lower frequency (longer wave) tone of the thumpers tends to be "omni-dircetional" it's as much "felt" as "heard" this is why you can place your subwoofer anywhere in your surround sound system.

But the higher frequency (shorter wave) "center channel" sounds (like a two stroke) need to be placed at ear level for optimum performance.

When your in the woods you can hear the big four strokes coming or going because the sound waves are more spread out, as opposed to the more linear two stroke soundwaves.

The pipe guys have to do something. or we all lose. we need to stop this "I won't give up 2 hp or 1 lbs of weight" and the "they better not mess with my closed course pipe!" mentality. The truth is as long as the "closed course pipes" are available, John Q. Biker is going to put them on their trail bike and ride it on public lands.

Tis better to ride with loss, than to not ride at all.

------------------
I'll ride until I can't kickstart my bike, then I'll buy a bike with the happy button!

AMA Member
Blue Ribbon Member
Colo. Off-Highway Vechicle Coaliation member
 
Joined
Nov 14, 1999
Messages
125
Likes
0
#11
I think that a noise cancellation system would be unfeasable for bikes. The systems I saw on an automotive show were very complex and took into account the shape and volume of the cabin as well as passenger head position. It was very precise stuff and only intended to pacify occupants of the vehicle...not bystanders.

I do think that there is much to be learned and applied from the automotive applications as far as sound wave manipulation goes. The systems for bikes only seem to absorb sound (most, very little). DynoMax and a few other performance muffler makers have made great advances in quieter systems by just incorporating tuned fins, dams, or whatever within the muffler that still allow for flow that is near straight-through designs. This is the technology that I think the motorcycle guys need to be copying.

Thump on!
 
Joined
Jul 7, 2000
Messages
168
Likes
0
#12
While I agree with notion of keeping the bikes quiet, where does it end. If 95db. is O.K. then the next time it will be pushed to 90db. and so on until mouse flatulence drowns us out. The gun lobby understands this and fights all legislation tooth and nail. Once you let the 'do gooders' dictate any regulations it won't stop there. Not everyone has to be happy with what everyone else does. To rob a Liberal ideal "share the misery." Simple fact is the people complaining about the noise don't want it modified they want it eliminated.
 
Joined
Dec 10, 2000
Messages
1,490
Likes
1
#13
Posted by Jonala

*My results showed that a insert that had a down turned pipe made no difference on my dB meter. The bike did "sound" quieter. I was surpised with that result.*

The reason it sounded quieter with the turned down tip even though the actual decible level was the same is because the sound was being directed towards the ground, where some of the sound energy was absorbed.
 

steve125

Lifetime Sponsor
Joined
Oct 19, 2000
Messages
1,252
Likes
0
#14
I'm getting rid of my DSP exhaust for the 250f. It shares the same can as the FMF. From a performance standpoint they deserve a pat on the back. But to mass produce a muffler(105db)thats this annoyingly loud, they could use a swift kick in the butt!
 
Joined
Jan 10, 2001
Messages
17
Likes
0
#15
It saddens me to say this....

You can make your bike as quiet as you want. I love the noise my 650 makes. I also ride in Nevada. I see 1 person in a 10 day trip in the hills, if I am lucky. That person is usually a cattle rancher off in the distance.

I agree with keeping you bike as quiet as you can. BUT, if most of Glamis can be closed because of a FLOWER, the public has gone completely NUTS. These are all excuses to ban off road vehicles.

It won't matter if we are off-roading on a silent invisible hovercraft. Someone will make up something about the impact to the pigmy shrew's feeding source. It's all a bunch of S%$T.

It's going that way with guns and your car is next. Visit Kalifornia. This place is pathetic.

Lastly, all of these saviors of the land-WHERE ARE THEY? I have spent a great amount of time outside and I have yet to see a tree-hugger(except on t.v.) These people are not even in the back country.

I loved life a lot more when I was a kid and was ignorant of how things work. If you ride a dirt bike, your government is out to get you. It's only a matter of time.



KDK
 

Neil Wig

Lifetime Sponsor
Joined
Jun 22, 2000
Messages
347
Likes
0
#16
MXN4FUN
Where does it stop? I'll tell you where it stops, when our bikes are quiet. There is two ways they are going to get quiet, one is throught technology, the other is from lack of use. One way or another, they will become quieter. Do you hear the lobby groups complaining about the noise caused by horses, or hikers, or pedal bikes. No, you don't, because it isn't an issue. When noise is no longer an issue, it will be that much less amunition to be used against us. Will we ever see bikes below 90 dB? I don't know, but I'm positive I would rather have a quiet bike to ride in the North Saskatchewan Forrest, than a noisy bike that I can't ride anywhere. Yes it's a pain in the butt, but we live in a politically correct, tree hugging society, and WE ARE THE MINORITY. You know that democracy Americans are so prowd of...majority rules....that aint us.
 
Joined
Jul 7, 2000
Messages
168
Likes
0
#17
Neil here in Wisconsin the trails I used to ride on are now only for horses, hikers and mountain bikes. They all complained about the noise and had motorcycles removed. Now hikers and horseback riders have joined forces to eliminate the mountain bikes because they cause erosion. No matter what we do it won't be good enough. I for one do not want to turn around and grab my ankles every time someone has an issue with something I am doing. Their agenda is clear banning all ORV's, this issue just gets the foot in the door. With loudness being subjective due to tone and frequency what could possibly make people who want no noise happy. I am fed up with political correctness and believe it is time to turn the tide. After all the good guy's are in charge now. Just for the record I have stock exhaust on my YZF's and think aftermarket pipes are loud. [Just slap Harley stickers on it and you can make all the noise you want.] Don't get me started on that!
 
Joined
Jul 16, 2000
Messages
6
Likes
0
#18
Amen on the loud Harleys brother. I never hear anyone complaining about the loud Hogs but when it comes to off road bikes it is a sin. I am personally tired of this !@#$. These people do not want us riding in the dirt, woods, dunes...etc. We are looked upon as destructive forces of nature. Stop trying to please them. You have got to fight for your rights. I am annoyed by a lot of things in life that are loud. One of which is a chemical plant near by that I hear 24hrs. a day. Semi trucks up and down my street make noise etc. etc. I deal with it. I have no intentions of causing problems and trying to shut the world down. Yes we may be a minority but I can garantee you that those who are against us are a minority also because the vast majority of Americans really don't care.
 
Joined
Dec 10, 2000
Messages
1,490
Likes
1
#19
A lot of those people that hate dirt bikes so much will gladly take there 4x4 Excursion or Tahoe down to the store for a loaf of bread at 10 miles to the gallon, or take their F150 4x4 offroad to go to a hiking trail or fishing creek, but it's something THEY approve of, so it's ok.
 
Joined
Nov 14, 1999
Messages
125
Likes
0
#20
In many situations, very loud bikes are not a problem but it is up to you to determine what noise levels are going to be appropriate before you head out. MX track in the middle of nowhere with no houses for miles? Let er' rip! Public land that sometimes wanders close to private land with houses and animals? Keep it down and ride by as quietly as possible.

Track owners should be aware of how far the sound carries on race day or busy practice days and take measures before it's too late.

Mention to Harleys was made. Do you want to be thrown into that category? I love the summers here but can sure do without Hell's Angels ripping down the street every ten minutes setting off every car alarm in town.

A rider at the track I was dicing with the other day later told me he couldn't hear his own bike (CR250) over mine and was having trouble deciding when to shift.

I can think of a lot of reasons to keep the noise down but very few excuses for way too loud systems.

Thump on!
 
Joined
Oct 16, 2000
Messages
8
Likes
0
#21
I think the noise thing is lame. Harley Davidsons are way louder than my dirtbike and no one is trying to make them quieter, And that is an every day thing that people have to deal with. I under stand the point of the topic and agree with what has been said on this topic about doing every thing we can to keep our riding places open. I just wish people would back-off.

------------------
James,
93 xr640,hrc cam,DS kit,super trap,K&N race filter,and LE suspension.
 
Status
Not open for further replies.