Do loud pipes save lives? Now you have the answer!

A research made with the support of the Department of Road Vehicles within the Polytechnic University of Bucharest together with noise measure experts from Enviro Consult - the local representative of Bruel & Kjaer.
We've all heard that "Loud pipes save lives," but is it true or is it just an excuse for those who want to get attention?
Do you know how a loud pipe is heard by a driver inside the car? We wanted to find out, so we measured it.
The results are surprising and we invite you to analyze them too!
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Important sections - Time Stamp:
1. 00:00 - Intro - Do loud pipes save lives?;
2. 00:55 - Motorcycle ban across Europe;
3. 00:59 - Study - test 1 to 5
4. 04:39 - Sound sample inside the car;
5. 05:18 - Sound sample behind the motorcycle;;
6. 05:38 - Conclusion;
7. 06:17 - Partners and support.

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About motoADN – Asociația pentru Dezvoltarea Națională a Motociclismului în România
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Romanian version -
Suntem înființați din 2018 și am început prin a promova eliminarea discriminării dintre motociclete și mașini în cadrul programului RABLA – program de finanțare a achizițiilor de vehicule noi. În februarie 2020 am reușit să "punem pe roți" prima ediție a programului Rabla MOTO – program de finanțare pentru motociclete noi.

În 2019 am luptat pentru ca Taxa OXIGEN, ce urma a fi aplicată din 2020 de Primăria Generală a Municipiului Bucuresti, să nu se aplice și motocicletelor.

Avem în derulare discuții cu administrații locale pentru a crea programe menite să susțină dezvoltarea motociclismului local.

Printre alte proiecte motoADN, în derulare sau în curs de lansare, menționăm:
- motoȘCOALA Zilei – program de promovare a școlilor moto din România
- motoSPOT – program de promovare a locatiilor ce au facilități speciale pentru motocicliști, dar și a unor trasee și puncte de interes moto.

Tot ce am realizat și urmează să realizăm este posibil doar cu sprijinul celor care ne sunt alături. Am reușit să dublăm numărul de membri de la un an la altul și acum te așteptăm și pe tine ca membru în asociația motoADN.

Singur, ești o voce, împreună, suntem o forță – Abonează-te la canalul motoADN și te însoțim în călătoria ta prin lumea motociclismului.

Link-uri importante:

Rebel în România, proiect dedicat începătorilor și tinerilor motocicliști

[LuciTulcea]

As a driver and a rider, I fully agree with the conclusions of this test. Only those respective riders can hear their shitty loud pipes, not the drivers.

[devideomeneer]

I love how y'all in the comments suddenly became acoustic experts after looking at a research with a outcome you did not like.

[ungureanuflorin]

Correct! Not loud pipes but a car horn installed on the motorcycle. It disperses unidirectional sound and can be acknowledged by any human from new born to the elders. Why? Well, because we are more used to the car horn then the loud pipe. So, I use a car horn for my bike and it does the job when needed.

[wiregrassga]

As a rider for 60 years I can't think of a situation where a loud pipe saved anyone. Skill and situational awareness saves lives whether riding or driving the cage. Loud pipes save egos.

[sgpsimonb]

I ride and drive in a bike city full of noisy bikes; Bangkok. My Land Rover had a 40-year-old diesel engine - I'd wager it is noisier than almost all modern passenger cars. I can hear loud bikes over my engine and road noise. I posit that the close proximity of other cars in traffic acts to reflect sounds from the exhaust. Lane-splitting is legal in many places and where it is bike exhaust noise will reflect off the front of vehicles behind and also be tunnelled along the sides of cars.

I think the set-up of your test is perhaps valid for open roads, but not roads with sidewalls and certainly not busy city streets. I look forward to your additional testing results.

Edit: Also, it may not be necessary to alert a can to change what they are doing, in some situations, stopping them from starting a move may be enough. 10+ meters is enough to hear right, then it's enough to stay in lane and not start to change.

[mktj]

I’ve been saying this for years. Loud pipes are dumb as hell. How good is getting hearing damage from what you’re riding. 🤦🏻‍♂️

[hermanderaeymaecker]

No surprise here. And they did not even take into account that a moving car adds rolling noises. But any car driver already knows this from real life traffic. You only turn heads from pedestrians and cyclist. Oh, it's their life we are saving. Got it.

[agisler]

Maybe bikers should actually learn defensive riding skills. If you are depending on the loud pipes saving your life then you are destined to be another motorcycle statistic.

[FYIfuckutube]

If loud pipes save lives, just think what learning how to ride would do.

Seriously, i’m sure we all know someone that lost it on a corner, or wasn’t paying attention.

[CalabusDabus]

The loudest motorcycle they measured was at 110DB, the same exact volume of most police sirens. Should police stop using their sirens?

[dojiijii]

Not sure what cars or motorcycles were used in this test, but even at highway speeds I can hear cruisers from inside my car. Long wavelengths (low sounds) penetrate solids much better than short wavelengths. A better test would distinguish types of bikes, and the frequency range of the exhaust sound.

[bikingwithgrantygrant]

I appreciate what you are trying to do with this test. I personally have quiet exhausts because over lon distance, I have found some exhausts to be too noisy over a prolonged period of time, however there are other factors to consider. Both OEM and after market exhausts have different levels of sound depending on the speed of the bike and the gear chosen. For example an OEM and aftermarket exhaust at 30mph in 6th gear will be extremely quiet but have both bikes in 2nd or 3rd gear at 30mph will have a completely different affect and may result in the driver hearing an after market exhaust better. Also engine configuration is a massive factor. A 650 parallel twin motobike with an aftermarket exhaust will sound different to an inline four 650 with the same exhaust. Rev bombing a bike isn't realistic either.

[gsx-phantom]

Test conducted at Car horns are generally 108-110db.... police sirens are 110 to 120db .... motorcycles range from 80-125db.... so this test is also saying that police sirens and car horns are also ineffective in alerting other road users to danger... the test here is flawed since it does not represent any real world scenario where a loud noise (bike engine or car horn) would actually have saved a life. I can absolutely guarantee ANYONE that during the entire history of motorcycling that a loud exhaust has saved a life (kid crossing on a blind bend for example).... yes it's likely to be an edge case however we have to remember that safety comes in layers and having a loud exhaust contributes to those layers.... yes they can be annoying but that is another argument entirely... just wait until silent electric cars and bikes take over... there's likely to be a lot more deaths outside schools and on country roads attributed to 'not hearing a vehicle coming'!!

[gerardv]

decent research, it give's a good indication of sound levels inside an car. to contribute a little to the cause and to inform the "loud pipes save lives" proffesionals in the comments i conducted the same experiment but in a dynamic setting with harleys and in a static setting with a enduro bike.

I used a class 2 db meter callibrated to 94db @1000hz. when driving 80kmh and being passed by 2 harley davidsons (aftermarket exhaust, vance and hines, two brothers) i could not get the db meter above 85dba inside the car. even after multiple tries, including a full throthle pass. the average enviromental noise inside the car was 68dba.

I also preformed a static test with a 600cc single cilinder enduro bike. the soundlevel outside the car @1 meter from the enduro bike exhaust under a 45 degree angle was 95dba @3750 rpm, 108dba whilst blipping the throttle(not rev bombing), and 110dba whilst driving by @ 1 meter full throthle. the same actions were repeated and this resulted in the next values meassured inside the car with the windows and doors closed: @3750 rpm @1m: 65dba. Blipping the throthle @1m: 73dba. Full throttle driving by @1m 75dba. these values confirm the pre study done in this video.

[mattm]

If I hear a loud bike while driving I rarely have a clue where they are. It's the scream of a 600 or the rubble of a cruiser coming from somewhere out there on the road. If i dont catch them in a mirror (which i likely would have done loud pipe or not bc i check those things like a resposible driver) i dont see them until theyre next to me or passing me. Now i know some of you will say "but at least u know a biker is around!" And what does that get us? Cars dont part like the red sea and let us through. The moron on their cellphone doesnt put it down and go shoot i need to pay attention. The idiot who never uses their blinker doesn't think shoot there's a biker around let me become a good driver all of a sudden. If anything all it really does is rile up karen and make her curse under her breath how she hates bikers. Lay this myth to rest and ride safe everyone ✌️

[lucferblack]

rev bombing is about the loudest thing you can do. if you can barely hear that at 15m then your not going to hear a loud exhaust on a bike doing 30 when you decide to change lanes. the only thing loud exhaust do is piss of people and save stupid pedestrians.

[brandonfitton]

I agree you can't really hear a motorcycle behind you on the highway. When a motorcycle passes you at 120mph you never really hear it until it's on top of you. Cars in front of a motorcyclist are also of least concern on the highway; "I'm so worried about that car 100m ahead of me that I'm going to pass practically on the white line or two lanes over from" said no motorcyclist ever, at least I never worry about it. What I and others do worry about are intersections, blind corners, parking lots, stop signs and other low speed circumstances where driver attentions is divided 10 different ways. Still, riding defensively and knowing where to place you bike for visibility e.g. not on the passenger side edge of a pickup truck when oncoming cars in a turning lane or waiting for a window of opportunity to "gun it" in traffic to make a left turn into a gas station they've been waiting for 6 minutes to enter during peak traffic and the driver says "okay, after that black truck and before that white car just zip across. I met a guy last weekend that lost his leg like that.

There must be some non-zero amount of collisions that were prevented from loud pipes but these aren't that loud compared to a big twin cruiser with Vance & Hines Radius pipes which dump the sound out to the back and side rather than sport bike exhausts that practically have wave guides built into the tips.

Also, this does not address that you use your exhaust like you would your horn at times, but with less ambiguity or having to hold on to it. Think of how annoying that would be: "what is that rider trying to tell me?"

All this and I'm still putting much quieter pipes on my bike if I can find them and it doesn't absolutely kill the performance.

It would be interesting to see a more holistic study of whether or not a driver will pull out on an electric bike or a sport bike with a slip on exhaust or a big twin cruiser with 110db shotgun exhausts. How you would study that would be extremely tricky (people pay attention when they know they're being tested and not driving home drunk on 4th of July weekend late in the evening with the windows down listening to Boston.

Lastly, maybe use cross power spectral density in your studies and not just dB and try to include cognitive factor and opportunity to costs e.g. revving and making person at the stop sign 40m ahead on the right actually make visual contact with the bike so the rider can pay attention to the car coming 47m on the left who is about to make a left turn that's going to make them go flying over the hood or into the 2x4 that's hanging out of the tailgate. Hard to capture.

[say..]

If you are so afraid to drive that you need a constant annoying screeching alarm to alert everyone of your presence then maybe you should pick a safer activity.😂

[NZSTROKE]

Explain how i can hear a bike behind me in traffic

[niceshot]

So you're saying motorcyles need to be even louder than a straight pipe exhaust, got it.