How loud for electric bikes

Discussion in 'The Perfect Line and Other Riding Myths' started by gmk999, Aug 26, 2013.

  1. gmk999

    gmk999 ____ as a Rotax

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    How loud does an electric bike need to be? I understand that they need to make some noise for safety purposes, (loud pipes saving lives and all).
    But how much noise and at what speed?
    Is there a top speed where the noise of an electric equals that of a combustion engine as there is with cars?


    And now the big Q.. for arguments sake.
    Do loud pipes save lives? Would you whiz along silently at 75 mph on the highway comfortably knowing that you cannot be heard by nearby motorists and pedestrians?
    Or scarier yet, at 25 mph through a school zone?

    Just askin'
    #1
  2. Mat

    Mat Long timer

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    Women were burned as witches because they knew a medicinal herb or two.

    People were scared of trains because of the unnatural speeds you could travel with, plus the steam locomotives scared the cows so their milk got sour.

    The first cars were required to have someone walk ahead of them with a bell or something in city streets.

    People got used to cars in the meantime (and then forgot again with the advent of cell phones).

    People will learn to look for cars and bikes instead of just listening and the world will keep spinning. Even with quieter engines.

    Moving your eyes saves lives! :deal
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  3. Jacl-Kampuchea

    Jacl-Kampuchea Booze Merchant

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    [​IMG]^ Okay Genius, but what about the blind or visually impaired people. They going to use their eyes, you think?

    It's a good question. I was thinking about it myself as I may buy an electric ds in the next year.

    I guess some kind of air catching device that makes a louder or quieter noise depending on the velocity of air passing through could work well.

    I don't subscribe to the "loud pipes save lives" stuff - but it is important to have some noise from cars and bikes. Just last week I had cut the engine on my bike 500m before I had to stop and some idiot walked straight in front of me. I had to brake hard. He hadn't heard a bike coming.
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  4. Raabe

    Raabe CAW CAW!!!

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    Seein all those fancy electric hybrids here in vienna i have to say that absolute ninjalike silence IS dangerous. PPL are used to hear at least something. If they dont hear anything they might oversee a (for example) car because since its silenced the brain tells you it must be standing still.

    BUT

    Loud pipes do NOT save lives. They just damage the ears and annoy everyone except the douche on the bike/car revvin up the engine. There is a huge difference between "standard engine sound", "no sound" and "OHMYFACKINGEAARS!!!". The last can scare people wich can lead to accidents (please note the little word "can")

    I would suggest that electric powered vehicles no matter if car or bike, have at least some sound even if it is via soundsystem a fake engine sound (heck that would be fun making a bike sound like a steamtrain). Specially for little kids no-sound can be troublesome.

    On the other hand, an not-intoxicated, situation-aware and sane driver with an save driving style saves more lives than loud pipes or electrics with sound.

    dat be jus ma two pennys. IMHO

    EDIT:
    Visual impaired are not going to use their eyes but they are more careful to begin with. But going that way, what about deaf people? They also got used to that. True if they were not able to see the car (camo anyone?) then they might be doomed. Same goes for blind ppl that cant hear the electric engine.
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  5. JimVonBaden

    JimVonBaden "Cool" Aid!

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    What ever happened to looking where you are going? How about looking before you cross the street? You going to put noise generators on bicycles next? :rolleyes

    Jim :brow
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  6. Grinnin

    Grinnin Forever N00b

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    There are cars that are similarly quiet.

    The electric motorcycles that I hear are not silent. Granted, I hear them in rural Maine where there is less competition. One DID arrive while I was inside the other day and I went out and was surprised that I had a visitor. If I'm outside I can hear them arrive.

    Later I went to a neighbor's where there's an electric Hayabusa. I could hear it well over 100m as it disappeared over the top of a hill -- couldn't see it then but could still hear it. Several minutes later I could hear it approach before it was visible over the hill.

    But I was listening for it. They are not loud, but they are still audible.

    Perhaps the question is how loud does it have to be to get the attention of someone who is paying no attention at all?
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  7. Dcc46

    Dcc46 Been here awhile

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    Let's not over think this. Put a baseball card in the spokes. Problem solved in 10 seconds for 10 cents. :*sip*
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  8. gmk999

    gmk999 ____ as a Rotax

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    Love it!! The best Ideas are the low tech ones for sure.
    Anyone here have a deer screamer on their bike or car?

    FYI there are laws pending for minimum noise limits on electric cars. I believe it's 54db.. but I have no idea how loud that is. Or if bikes are included in the law.
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  9. JimVonBaden

    JimVonBaden "Cool" Aid!

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    54db is just above background noise. The electric motor and tires on a car will make that. Stupid law. Then again, typical.:norton

    Jim :brow
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  10. car94

    car94 What's this Box for?

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    Here are some Racing at Indy, I think they all have stock Mufflers!!:D Click on the image to play the Video!
    [​IMG][/URL][/IMG]
    The safety car is louder than the whole pack!
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  11. LuciferMutt

    LuciferMutt Rides slow bike slow

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    Well, considering some fucking idiot strolled into the street (without looking) in front of me while I was in the Miata doing 35 MPH the other day, no amount of noise is going to help people who are not paying a lick of attention.

    The air horns sure made him get the hell out of the way though :deal:lol3
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  12. OrangeYZ

    OrangeYZ Been here awhile

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    Somewhere between a freight train and an F-15 Eagle
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  13. Chip Seal

    Chip Seal Long timer

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    On my morning walk, I hear the Priuses [Pious] coming down the road. Their tires make noise just like other cars.
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  14. DirtMedic

    DirtMedic Intrepid Explorer

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    I am a firefighter/paramedic. Ask anyone in the business... people don't hear our sirens, air horns, and Federal Q so they aren't going to hear your motorcycle no matter what you do to it. The idea that loud pipes save lives is crap. You outrun the sound produced somewhere between 45 and 60 mph. (Wait a minute. Maybe I answered why Harley riders don't ride over 45 mph.:D) You can't get around the laws of physics. I respond to plenty of wrecks for riders with those loud pipes It didn't do them any good. Riding defensively and wearing protective gear (especially a helmet) will go a lot further. All you do with loud pipes is make the average citizen angry and give the rest of us a bad reputation.

    http://www.examiner.com/article/the-loud-pipes-myth

    I had the opportunity to test ride a Brammo Empulse. It was not silent by any means. The motor had a pretty good whine to it. It was however, still an over all quiet bike.

    I don't see electric as practical yet. The range is too short, the recharge time is too long, and for the increased price it doesn't offer any practical advantage over a gas powered bike. Having said that though, the acceleration sure put a smile on my face. It was a lot of fun. If it was a daily commuter for short distances to work then I could see it. I like to travel on my bike and that is a limitation an electric bike cannot currently overcome.
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  15. Mat

    Mat Long timer

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    Uh and what about the deaf and blind? Oh hell let's just all stay indoors just in case.

    Or maybe have blind people get a dog. My blind grandpa's main reason why he never walked around the block by the way was dogshit on the sidewalk. He didn't want to clean his shoes every time after a little walk. Blind people in Europe routinely have to deal with much quieter vehicles than electro bikes: bicycles. They learn to manage.

    Again, sour milk anyone? Or maybe electro smog from the motors? Anything else?


    PS: you outrun the sound once you go somewhere around 750 mph or so at ground level ;-)
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  16. DirtMedic

    DirtMedic Intrepid Explorer

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    Mat, you are confusing the speed of sound with its effective range of volume. It is very possible to outrun the sounds of sirens and loud pipes. It is why those loud pipes and sirens are annoying AFTER it has passed. It doesn't get your attention until it is right on top of you. It is too late then. Think about the last time a cop or fire truck was right behind you before you noticed them. Their siren was on since they left the station.
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  17. Vulfy

    Vulfy Been here awhile

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    Ok, I think you need to rephrase "outrunning the sound" a bit. Sound travels at around 760mph.
    I think what you mean is you might be outrunning the reaction time of the brain. The more distracted you are, the longer it takes you to realize that that sound is actually a siren behind you. You did hear it from a long distance, but you might not be reacting it, and not realizing what it is.

    So no, its not physics but rather biology/neurology/psychology.
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  18. dwayne

    dwayne Silly Adventurer

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    Knobby tires will make almost as much noise, and are arguably more cool.
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  19. Ogre_fl

    Ogre_fl Long timer

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    Highway...absolutely.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:eek:ffice:eek:ffice" /><o:p></o:p>
    When I ride or drive at highway speeds I don’t "hear" any other vehicles and if I do its only because they are obnoxious.
    IMO My bike could be absolutely silent it would not make a real difference.

    In town, congested area, lots of parked cars, lots of pedestrian traffic.
    Maybe I would be extra cautious knowing I could not be heard, but honestly not any more than I allready do in that sitiuation on an ICE bike.
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  20. DirtMedic

    DirtMedic Intrepid Explorer

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    No, I do mean "outrunning the sound". It is the common phrase used when discussing this phenomenon. A jet engine and a whisper both produce sound that travels at the same speed. Temperature, humidity, and atmospheric pressure all affect the speed of sound, however, it is around the number you quoted. The difference is in the frequency and decibels produced. As for frequency, the Doppler Effect plays a role in what we are discussing. As a sound producing object moves at greater speed it compresses the sound waves raising the frequency. Higher frequency sounds do not have the ability to travel the same distance as lower frequency ones. It is why you hear a loud motorcycle for a longer period of time as it roars away than when it was coming towards you. The second issue is decibels or volume. While both sirens and loud exhaust pipes have higher decibels, it must be taken into account that there is a limited range that those sounds can be heard as decibels decrease with distance. The sounds in question are further diminished with modern sound deadening materials used in today's vehicles. Those sounds produced must compete for the listener's attention with other sounds as well. As speed is increased, the time for a listener to hear the sound, register what that sound is, and then react appropriately to it is shortened the faster the object is moving. That is what is meant by "outrunning the sound". Studies have shown for emergency vehicle sirens, the speed an emergency vehicle can travel where another driver has the ability to hear, distinguish, and react is limited to the emergency vehicle driving at 45 to 60 mph. Emergency workers are trained to respond to calls with an awareness of the limitations of the siren to get the attention of other drivers. Loud pipes are subject to the same issues. The original poster posed a question about electric motorcycles and sounds produced in reference to safety. Increasing your decibels will have minimal effect on the reaction time of other drivers. Defensive riding and safety gear are much better areas to place one's concerns and energies to remain safer. In the few instances where a loud noise will make a difference, simply install a louder aftermarket horn. Loud pipes have the effect of giving the average citizen a bad opinion of motorcyclists, but that is the point for some riders.
    #20