Loud pipes save lives? Horn v Exhaust - Decibelmeter results

[c_dug]

So often in filtering crashy threads people (myself included) claim loud pipes save lives, then others (usually rogerborg) tell people to use the horn more often.

So I decided to test this scientifically and borrowed the work decibelmeter whatsit!

My videoing skills aren't brilliant, though at least I can hold the phone horizontally. Excuse my jabbering voice We tried to make sure to record background noise, tickover, 5krmp, redline and horn in both videos, not in the same order but should be obvious enough what's going on by the sound.

First video is my Diversion 900 with Delkevic full system. The horn is a Fiam replacement, aged and weedy. Divvy.

Second video is el_oso's K5 GSXR1000 with Yoshi Trioval end can. Also the alarm at the end just for lulz. Gixxer

We've got a couple more bikes to test at some point, I'll happily do anybody else local too if you drop me a PM.

Not sure what to conclude from the video's, I'll leave that up to you lot!
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I am a bellend, I am a man of constant sorrow, I am a gummy bear, I am a rock.

[barrkel]

It's hard to justify using a horn constantly, whereas the exhaust is always on. So simple loudness isn't enough.

The exhaust can be heard even when you haven't seen the pedestrian about to emerge from between two cars. You have to see the hazard to let them know you're there with the horn.

A proper scientific study would track two populations of riders with similar skills and risk taking profiles, one with loud pipes and the other with stock. Would possibly be unethical though.
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Bikes: S1000R, SH350; Exes: Vity 125, PS125, YBR125, ER6f, VFR800, Brutale 920, CB600F, SH300x4
Best road ever ridden: www.youtube.com/watch?v=s2MhNxUEYtQ

[Albigularis]

The horn is a reactive method of attracting attention when you desire - "Beware - I am here".

The exhaust is a proactive method of attracting attention regardless of the situation "I am in the vicinity" or "Ticket me, there's no way this is legal".

I've just come from a Street Triple with a fully unbaffled Arrow system that was loud to an antisocial level, and I'm now on an il4 with a standard exhaust. It's been a week and I am already noticing people taking more action in front of me, because before they could hear me. The most common place to witness this is a car park. The bike pierces through the air like a knife with a loud can, people take care moving around when they hear you because they realise "I can hear something but can't see it yet". With the standard pipe on the new bike, people can't hear me, and are not looking for that thing they can hear but not see.

Whereas the horn signifies "You're about to hit me". Or more commonly "The light's just changed to green - WHY AREN'T YOU MOVING YET?!".
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Biking history so far-
Aprilia RS125 - Kawasaki ZXR400 - Triumph Street Triple R - Suzuki GSXR1000 L3 - BMW R1200GS - Kawasaki Z1000 - Kawasaki ZX10R C1H - Ducati Multistrada 1200 S Touring - Suzuki Hayabusa

[mattyfattyboo...]

I just have thoughts of someone riding round with the horn wired up to be on all the time now

[c_dug]

I was more envisioning a scenario where a car begins to pull out and somebody has the option of hitting the horn or pinging the engine off the limiter.
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I am a bellend, I am a man of constant sorrow, I am a gummy bear, I am a rock.

[Ste]

Loud exhaust is offensive and using the horn is defensive.

[Wave2k]

certainly feel safer, and less people pull out and cut you up so it must work.

I like to hear my v twins roar .

The v8 car ain't too bad either .
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Ducati 1299 Panigale
2009 Corvette C6 z51
RS125->CBR400->RXS100->GSXR750K2->Ducati749S->CBR600RR5->TL1000R->DRz400->RSVR1000->Honda VTR SP1->CBR400->GSXR1000K6->Honda H100->CBR600RR3->Ducati1299

[Triton Thrasher]

[iooi]

A loud pipe will increase in volume as you get closer, so is easily missed as it blends into the background noise. So will not be noticed as much as a quick blast of a horn.
Noise is all relative to just what the car driver is doing. Often you can hear their music while sat on a bike.
So how the fuck they will hear a exhaust is beyond me...... When you cant even hear your own (not a quiet one) because of their music, despite wearing a helmet.....
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Just because my bike was A DIVVY, does not mean i am......

[el_oso]

I don't think that a loud can really makes that much difference to car drivers. I think it only makes a difference to pedestrians.
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Duke 390
Previous: '05 XR125L | '96 XJ600S Diversion |'05 Suzuki GSXR1000 | '05 Honda CBR125-R | '97 YZF 600R Thundercat | '11 Honda CBR250
Car: Jeep Wrangler 4.0L

[Albigularis]

[Rogerborg]

[Triton Thrasher]

[Snod Blatter]

[Wave2k]

IL4 is harder to hear but you can certainly hear a twin behind you in a car .

there was a definite difference from when I switched from standard to sports exhaust , which was whenever I got a new bike.

I have no figures, I don't think there has any been any real research , I can only tell you that for me being heard certainly for me meant being see more, especially in built up urban areas around London.

plus , I like to hear the sound of my bike, part of the fun .

Why would you own a quiet Ferrari , half the enjoyment is the sound of the beautiful engine .
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Ducati 1299 Panigale
2009 Corvette C6 z51
RS125->CBR400->RXS100->GSXR750K2->Ducati749S->CBR600RR5->TL1000R->DRz400->RSVR1000->Honda VTR SP1->CBR400->GSXR1000K6->Honda H100->CBR600RR3->Ducati1299

[Albigularis]

[RhynoCZ]

I say, see and be seen is the key to survive, not to piss people off.

I do admit, that sometimes, the roar from an open exhaust system makes things easier, though. I've noticed this when I came from my '88 GPz with open exhaust to the CB-1 with stock exhaust system. The CB-1 was so quiet, that even though I was going 35mph, pedestrians though I was slow and just walked right in front of my motorcycle.
The GPz was a whole different story, people actually made 2-3 steps back, when I was approaching them, even though I was actually slow.
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'87 Honda XBR 500, '96 Kawasaki ZX7R P1, '90 Honda CB-1, '88 Kawasaki GPz550, MZ 150 ETZ
'95 Mercedes-Benz w202 C200 CGI, '98 Mercedes-Benz w210 E200 Kompressor

[Wave2k]

Well there is certainly a difference between a sports exhaust and an obnoxious cut off exhaust and it's important not to put the two in the same pile.
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Ducati 1299 Panigale
2009 Corvette C6 z51
RS125->CBR400->RXS100->GSXR750K2->Ducati749S->CBR600RR5->TL1000R->DRz400->RSVR1000->Honda VTR SP1->CBR400->GSXR1000K6->Honda H100->CBR600RR3->Ducati1299

[johnsmith222]

the loud pipes save lives thing is just a way that some riders try to justify to themselves and others why they have a loud exhaust.

If you need a loud exhaust for safety then you probably shouldn't be riding on the road.

I had a race can on my ZX9R for well over a year. Shifted back to the stock exhaust just now because I can be out at night and don't want to piss off the neighbours, but now im not using the bike so much I might go back to the race can.

Purely for broom broom noises.

https://www.youtube.com/watch?v=xGyKBFCd_u4

Interesting to notice that many of people with loud exhausts dont take to cheaper methods to potentially improve their safety (High Vis, bright orange helmets etc).

Forgetting the high vis blending in argument.

[Wave2k]

Stock is far too quiet for me , and actually retracts from the enjoyment of riding for me.
bit again, you can still fit a road legal aftermarket can that is louder than standard but not obnoxious .

And in my eyes safer.[/i]
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Ducati 1299 Panigale
2009 Corvette C6 z51
RS125->CBR400->RXS100->GSXR750K2->Ducati749S->CBR600RR5->TL1000R->DRz400->RSVR1000->Honda VTR SP1->CBR400->GSXR1000K6->Honda H100->CBR600RR3->Ducati1299

[Aff]

I like feeling like a super hero with the power to create sound with my right hand.


Oh and it save lives and stuff innit.
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Current Bikes:Honda 929RR Fireblade, Honda CD200 Benly (Project), Stomp Z2 140
Electric Bike Project

[G]

[Clanger]

I think bike horns sound pathetic.

Mine never sound as annoyed as I feel when I give it a blast. Revving the engine and listening to the noise from the exhaust is closer... we should be given the opportunity to have horns that shout louder.
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Be who you are and say what you feel, because those who mind don't matter, and those who matter won't mind - Dr. Seuss

[RhynoCZ]

[talkToTheHat]

I'm not sure I could fit a train horn between the front cylinder head and front wheel, even if I were to try some extreme rake adjustments. I'd also kiss goodbye to riding in town without earplugs.

Most low frequency engine/exhaust noise will blend into the surrounding traffic on a busy road, yes it may work as a passive alert over short distances but it is likely the sound may not carry as well as a decent horn, which, significantly, is intended to be used to aleart other road users to an unobserved presence and works rather well for said purpose.

I shall try to run frequency analysis on the youtubes when I get into the studio. Note that the human ear is more responsive to some frequencies than others, so a straight dB reading can be misleading.

I have a cheap pair of 'loud' aftermarket snail horns. DrBike or bike it, cant remember which, from m&p's ebay store. They are a reasonable upgrade on worn out OEM horns without being unbearably loud.
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Bandit. does. everything.