There are two reasons. The first is technical. Motorcycles have short exhaust systems, which in turn makes it more difficult for them to be quiet. The second is practical. A motorcycle is a relatively small vehicle, and as such is easier to overlook by other drivers. "Loud Pipes" are more likely to catch the attention of other drivers. (Have you ever noticed the bumper stickers with a picture of a bike on them that say " Loud Pipes Save Lives!"?)

I am pretty sure the real reason is that the owners like it that way. I have co-workers who bought brand new Harleys and before even taking delivery, they had the dealer take off the factory pipes and put on louder pipes for that attention-getting sound. There are plenty of overpowered 1000+cc bikes out there that are quiet, demonstrating that this is not a technical issue. High-performance off-road two-strokes tend to be louder than their four-stroke street brethern because to squeeze the most power out of a two-cycle engine you have to tune the exhaust system to help evacuate the cylinder during the exhaust phase of the stroke. On any high-performance vehicle you don't want the extra weight of the sound-supressing hardware so on racing bikes the exhaust pipes are optimized for moving exhaust gas rather than minimizing sound.

Motorcycles are not usually loud with its stock exhaust, they are usually loud when they change the pipes to aftermarket pipes which are louder then normal. Also when some people want to make the bike louder they remove their baffles which are inside of the pipes and that is really loud.

There is another reason, also technical; “high-flow” exhausts (such as the un- or minimally baffled pipes on many motorcycles) allow for the production of more power, especially at high RPM. That’s also the reason you’ll see short, un-baffled pipes on drag cars and other high-performance applications. There is a trade-off, though. The lack of backpressure on the exhaust valves can shorten their service life and/or produce catastrophic failure.

For off road motorcycles a 2 stroke is loud but can be even louder. A 4 stoke is also loud, and a 2 stroke is being banned.

coz their motors are screwed or their owner wants attention

Often you hear the phrase "Loud Pipes Save Lives" this in fact is false with no science or evidence to back the argument. If it in fact was the case, the Insurance Lobby would be supporting "Loud Pipes". Besides with the "Doppler Affect" the sound waves are not effectively heard until the motorcycle is past, plus the exhaust is projected to the rear of the motorcycle. The other moronic part of the argument is the biker will have the sticker "Loud Pipes Save Lives" and next to another that says "Helmet Laws Suck" and the same biker will probably be wearing a non DOT approved helmet. All this tends to make the safety argument moot. Final point, when one buys a motorcycle he /she should be aware of the preceived risk and if they are that afraid they should stay on 4 wheels. I'm a bicyclist and motorcyclist I have no noise and I respect the rights of others. Besides the noise pollution loud pipes are illegal.

In regards to Thom64, I should of mentioned my state of New York, wherein the Vehicle and Traffic Law sections 375-31a & b as well as 381-11 and 12. It is unlawful to modify the exhaust system to be louder then the system that was orginally factory installed, also straight pipes and mufflers with removable baffles are unlawful. Naturally different states have different laws. Also one should take into account the federal statutes on noise pollution. However they are moot as they are only enforced on manufacturing.

The short answer is because their owners like them loud. I have stood next to a friend’s high-end BWM that was so quiet I had to look at the tach to make sure it was running. Noise laws are much stricter in some countries and I’ve see the same model H-D as the one I ride that was far quieter than mine was from the factory. No motorcycle has to be loud. The exception would be bikes optimized for racing. To get the highest performance from an engine you want to get exhaust out of the way as quickly as possible. Racing bikes have short “drag pipes” without mufflers to maximize exhaust flow. Drag pipes are okay on the drag strip. But some people use these pipes on street bikes and they are unnecessarily loud. Motorcycle manufacturers are required to conform to EPA and other government regulations for motorcycles sold in the USA. Stock bikes, even big Harley’s, are not obnoxiously loud. But many (if not most) riders customize their bikes and aftermarket exhaust systems are a popular mod. Most aftermarket exhaust systems come with baffles than can be used to tune back pressure and reduce noise. Some owners choose to leave them out and that makes a bike louder than it needs to be. The way some riders run their bikes causes problems too. Even a stock bike can be uncomfortably loud if the rider “blaps” the throttle. Some cities (like Daytona, FL) have passed noise ordinances as a result. Once again, a few inconsiderate idiots ruin things for everyone. There is no good reason to goose the throttle while stopped at a light except as the motorcycle equivalent of masturbation. Loud pipes do not save lives. Ever passed an 18-wheeler in an adjacent lane with the windows down? That’s pretty darn loud but it doesn’t prevent accidents between cars and trucks. Most cars today are fairly well insulated and with the radio turned on a bike would have to be as loud as a jet at takeoff to be heard over the music. Loud pipes do not save lives, they just annoy the neighbors and the cops. I like loud pipes and I like a deep exhaust note on my bike. But I also respect my neighbors and other drivers. There are far more effective things a biker can do to be safe than ride an obnoxiously loud motorcycle. -------------------------------- Update Re: Framus' "Loud Pipes Violate Rights" comment. I agree. I am of the libertarian "let those who ride decide" school of thought. I am active in ABATE and oppose helmet laws and laws that prohibit things like modified intake and exhaust systems, handle bar height, etc. I do not believe that the government should enforce anyone's preferences on others. That said I have to fault those bikers who (ab)use their loud pipes to annoy others. It's not a "chicken or egg?" question: loud pipes came first. Inconsiderate riders irritated so many people that laws were passed in response. I personally LIKE loud pipes with a low exhaust note but there are times when a bike is so loud (and revved so obnoxiously) that it bothers me. Here’s a question for bikers that like loud pipes: how would you feel if someone started and revved a bike with drag pipes 6’ from your head while you were sleeping? This happened to me in 2003 when I was camping at Rider’s Ranch during H-D’s 100th anniversary. My first reaction was not “Cool pipes!” and I doubt yours would be either. If you wouldn’t like being blasted by drag pipes at random, why would you expect non-riders to put up with it? I believe riders should be able to install aftermarket exhaust systems even if they can be loud. But that does not give bikers the right to blast down residential streets late at night blapping their pipes to set off car alarms for amusement. I have seen this done repeatedly. I have been places where bikers sitting at a light revved their engines so loud that shouted conversation was impossible. A biker's “right” to install loud pipes does and should not obligate non-riders to endure excessive and unnecessary noise. Daytona City Ordinance 42-216 was passed in 2003 after a slew of complaints from residents during bike week. The ordinance prohibits anyone on a public street from creating noise "for the purpose of drawing attention to the source of the noise." Sound familiar? Daytona didn't have a noise ordinance for sixty six years until throttle-jockey posers on Main Street became so obnoxious that residents demanded a law. That took some doing in a city that takes in millions of dollars each year during Daytona Bike Week. The fact that there was no noise ordinance in Daytona from 1937 (when Bike Week started) until 2003 shows how a few jerks can ruin everyone's good thing. Sonny Barger says it perfectly: "Treat me good, I'll treat you better. Treat me bad, I'll treat you worse." If all bikers with loud pipes were considerate of non-riders there would be few noise abatement laws. But as long as a few insist on “rapid throttle advance” … “for the purpose of drawing attention to the source of the noise” there will anti-noise laws passed. And, unfortunately, the way our government tends to work is not by passing laws that mandate a desired outcome (i.e., no unnecessary noise) but by passing laws that mandate HOW a desired outcome is produced (i.e., no modifications to exhaust systems). If intelligent bikers apply peer pressure to our less considerate brethren things won’t get worse. If not, they will.

I beleive the real issue here is the rider and not the bike. I have a loud bike. My bike has been modified for high milage riding. After I completed the motor work it was necessary for me to change the pipes to get the proper performance. Actually I dont like it as loud as it is, and I have tried to modify the pipes to change the sound. But, in order to maintain the proper backpressure I am still going to have loud pipes. I respect my neighbors and do not cause excessive noise. However, I would like to address two issues which have come up. 1.advancing the throttle - I agree that a majority of the time this is done as an attention getter, but keep this in mind, How many Harleys are on the road that are stock? Most Harley owners have made some type of modification to the performance of their bike. In my case the size of my cam and the adjustments made to my carb require a rich fuel mixture. After sitting at a stop or riding at low speeds it is necessary for me to clear the carb. Now, I dont crack into the trottle in an attempt to bring rain down, but just enough to clear the carb which prevent valve damage and reduces the potential for backfire. 2.noise vs. safety - Some of you must live in a part of the country where there is no deer population. I have 2-3 deer walk in front of my truck weekly. Not the case on my bike. Deer hate the noise bikes make and they stay far away. With that being said, I do agree with you that there is a lot of excessive noise made by bikers. All bikers are different and I think anyone with any riding experience(18yrs, 162k miles) will agree that no two are the same and trying to stereotype any one person cant be done. You will get the same response from a sport bike owner when you call the bike a death trap. Its not the bike its the rider!!!! The "Bike Hater" will find a problem with anything on 2 wheels, but I hope the rest of you find this constructive.

The statement of "Loud Pipes Violate Rights" is simple. Operating a motorvehicle is a privilege granted by the state, whereas living in quiet peace and comfort is a right.

I agree with two points: It's either for a personal satisfaction to supress a lackness, which can be an ego issue at the end, or to be recognized on the street by other vehicles, human beings or girls. But this all have to be a man thing and I wonder if there is any girl outta there who has modified her bike to sound louder.

Annoying levels of noise, AND noxious odors are absolutely things that MUST be controlled by laws. The reason is obvious, there are a large number of totally rude people that could care less about their neighbors. It's just a shame that blanket laws seem to be the only way lawmakers finally fix these thing. Outlaw smoking in EVERY public place regardless of what measures business owners devise to make everyone happy there is one example and another like it is a law making it illegal to put any other exhaust system other than the one that came with the motorcycle no matter what else might be avaialble. But if anything sucks it is how fricken stupid and RUDE the people that made it such an issue to begin with! Next we need laws to protect the public against the idiots that take their crying screaming tantrum throwing infants and toddlers to places like restaraunts and movie theaters ... too many parents just try to ignore the behavior and go on watching the movie or enjoying the movie not giving a rats @$$ apparetnly about all the other patrons. Now I raised 3 sons so don't think me heartless toward these parents that just want too have a night out like everyone else. Bottom line for us was, unless we had a sitter we just didnt go out to these places ... it was WRONG to. I think there needs to be more public butt whippings of rude persons. Just yank the idiot off of his motorcycle at the next stop light and just friggen wail on him, and then tell him "NO MORE! same with the rude smoker and the toddlers parents. Just beat em to withing an inch ofbecoming unconscious and tell them "NO MORE! Got it?" Take that cigar or cigarette from the rude smoker and after a sufficient subduement, make them eat it, and tell them "NO MORE!!

I take it you are comparing them to cars. Motorcycles dont have the sound proofing of larger vehicles. And usually in comparison to an average car the typical media image is of a harley with big V twin engine roaring its way through a twisty Arizona road. On my Triumph though, even though the exhaust is loud, I notice there is also a loud gearbox whine which can be heard aswell as the engine. Road noise and wind noise too if the bike is travelling a t speed. Motorcycles arent the most aerodynamic of vehicles. My bike isnt really that loud, but comparing the engine size on my car to the bike (1100 to 955) there is abig difference in noise - just look at the length of the exhaust system on both machines.

The reason I have loud pipes, Is because if you can hear me, you're gonna see me. Not because I demand attention to show you how cool I am, but because people DO NOT look for motorcycles. At least us bikers are paying attention to safety, while you talk on your cell phone. I can't count the times I have seen a car at a stop sign that the person is gabbing on the phone, & didn't see me coming, so I pull the clutch, rev it once, & amazing how they hit the brakes & see me. Imagine that. Loud pipes also help with animals running out in front of us. Soo--- If I can't have loud pipes, don't plan on mowing your lawn, because that is loud & bothers me.

Many people say that bikers only have loud pipes to be "cool". Sure, some do. You can usually tell them because they are obnoxious. However, there is a good reason for it for many of us, especially if we have been around for awhile. The saying "loud pipes save lives" is accurate. I am not talking those "oh Gods I hear you a mile away and my windows are rattling" sort of pipes. That is just ridiculous. The average car driver is not paying attention to us and is perfectly willing to continue to not do so. They do not hear us if we are in front of us but they do hear us if they are beside us or behind us. They just might look for where the noise is coming from. If their windows are up and the stereo is on, the biker is screwed in this department. That is when "keep on your toes" comes in. Loud pipes are no excuse for not following good common riding sense. It can save lives to be able to grab some throttle and make some noise. It also can save our lives for that car driver to hear us coming and, at least, look. Assuming, that is, that the driver does not have his windows up and the music on. I know that when I am driving I hear a loud bike. It makes them easier for me to see. But then, when I am driving I am also hyperaware of bikes. So, the louder bikes (not obnoxious) you see bikers ride are not all for bluster and blunder. The obnoxious ones are just obnoxious. Many manufacturers, such as Harley Davidson, design the pipes to be loud for rider preference, for whatever reason.

Because the owner has removed the silencer (or whatever) out of choice (we are all supposed to look as they go past and be impressed). Unfortunately, most people do not notice the actual bike as they are too absorbed in the god-awful racket it's making.

Because some idiot made it loud because they think they are billy badass.

If you remove the baffles from your exhaust the bike will be louder, but removing the baffles also reduces the back pressure of the exhaust which increases power and increases the miles per gallon. My rice burner (Suzuki Intruder) gets 40-50 mpg gepending on how I drive, so I don't NEED to remove the baffles. On the other hand, a full dress Harlety may only get 20 mpg. Remove the baffles and it could go up to 30 mpg.

#1because we like them that way #2 because we need to heard by the people driving cars & trucks # 3 performce

They do it on purpose because they like the noise and also some will tell you so they will feel safer since other people on the road will hear them coming. So they put on aftermarket pipes, chrome of course, to sound even louder:-)

Owners craving attention. Loud pipes do more harm to the overall motorcycle community than any other actions. Several communities and parks have banned all bikes because of this. As an owner of a Honda Goldwing, one of the quietest bikes around, this is very unfair. As far as performance from a V twin with straight pipes...its a joke, the GL1800 has a 0-60 time of 3.7 seconds, quarter mile time in the 12's at over 100 mph and it is very quiet, this is a 900 pound bike. riders need to be more educated and just enjoy the ride, no need to show off for the general public all that does is give us all a bad rap.

Because their owners are self-centered. They consider only themselves (their enjoyment of loud combustion and the illusion of personal power that they experience) and fail to consider the detriment imposed on others (perhaps hundreds or thousands of people within a several-mile radius) by their noise.

Just a little FYI for all of you - Im willing to sacrifice the disruption of all of your piece and quiet for my protection. State law or not. As for the people that don't wear protective gear and have loud pipes for the reason of such.....there's a difference between getting hurt from an accidental spill or a flat tire and some @#$hole runnin us over cause he couldn't turn his head b/c the phone would have slipped off his shoulder. Couple more things: Noise Pollution? Is that even real? Give me a break! How 'bout the cigarettes you smoke, the SUV you drive, or the trash can you take to the curb every week filled with recyclables. Here's one for you "noise wave from behind guy". You'll hear my bike behind you, windows down or not. Unless of course your heads up your @#$. Loud pipes do save lives and I challenge you to contest a civil suit in court, if I survive your momentary lapse of judgement, that I came out of nowhere. I consider myself to be a pretty responsible-respectful guy and am not one for revving my engine for no reason. So, on that note, I think I'll let myself slide for interuppting your conversation or phone call during the few seconds it'll take me to get around you. I'll even wave to your kids in the back seat. They'll like that.

That motorcycle you see there, the one that's not at the side of the road, but still running, that's a BMW. And that red streak you saw to your side, um yeah we call that a Dukati. These are real bikes ladies and neither of them annoy the crap out of your neighbors. The rest of you idiots with your loud pipes keep crying that they're a safety precaution, yet most of you don't wear a helmet, so yeah we know your "all about safety". Natural selection at it's best. What you need to do is to get your girlfriend to ride topless, then I'll notice you better. Oh yeah, and you old guys who insist on mowing your lawns everyday need to spend more time driving around needlessly with all those motorcyclists on the road with no helmets. There, I've solved both problems.

Perhaps, Police can start ticketing bikers with pipes that are too loud. They drive by my house, wake my kids, scare the neighbors dog and basically ruin any chance of peace and quiet. Don't get me wrong, Bikes can be a lot of fun. But the fags with the overly loud pipes should just grow up already. We hear you on your bike and we aren't impressed. Sounds about as impressive as a the Dodge Neon with humongous spoiler and too loud pipes that's driving right behind you. Overly loud pipes don't save lives, loud clothes do! In fact, I think you'll find less people want to run you over, if you stop waking their kids up at 3AM with your rediculously loud non-factory pipes.