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Thinking caps on Netrider

Discussion in 'General Motorcycling Discussion' started by smileedude, Mar 4, 2011.

  1. It is time to get our collective wit and penmanship into action. A paragraph has appeared in Column8 whinging about the noise a bike makes.

    For those who haven't read Column8 in the Sydney Morning Herald it is a place to discuss, well anything interesting and usually unrelated to the news. Published responses are usually short and witty.

    Also the websites cut the last of the paragraph off. If anyone has a copy of today’s SMH can you please finish it off.

    If anyone can get anything published, 100 points. But I propose putting your responses on here for tweaking first.

    email responses to column8@smh.com.au

  2. that link does not work.
  3. My response is "you haven't heard my car."
  4. Lars Newman, of Fairlight,

    Motorcycles make more noise than cars so that blind and deaf pricks like you can hear us coming.

    Grumpy Ol' Man
  5. #6 17SJS, Mar 4, 2011
    Last edited by a moderator: Oct 24, 2015
    I'd be asking Lars for the details of the equipment he used to measure and record the dB levels, and what his sample size was for the study.

    Then I'd probably make up my own statistics to counter his. Something along the lines of 'more than three quarters of drivers don't look for bikes on the road, unless they can hear them.'

    May as well play the same game...

  6. My 2c - reject the premise. I'd be looking for sales brakedowns of the number of bikes sold in each capacity (most bikes sold in 2010 were 1 Litre engine - are most cars 4 litres?) and then the EPA sound levels expected of cars and bikes.

    The writers argument is not based on fact: debunk it rather than debate it.
  7. How about something along the lines of "On the road motorcyclists are regularly run down, injured and killed by the reckless action of cars, yet few if any cars are ever knocked down by motorbikes. Why should we on motorbikes settle for this? A little bit of extra noise to make sure that we are noticed surely cannot be that bad."
  8. All bikes are allowed an extra 4 decibels of noise, which is roughly 2.5 times louder than a car - not 4.

    Any argument that virtually every HD is running an illegally loud exhaust is rendered moot by the fact the same can be said about a lot of V8s and Japanese imports. If you're ignoring the law you can make a 5-6L V8 a LOT louder than a 1-2L twin.
  9. From an engineering standpoint, part of why bikes emit so much noise is due to just how much space and mass effective noise control equipment takes up.

    In aerodynamic terms a bike only uses about 10 horsies or so to do 100kph while a car uses 30 or so horsies, about 1/3 the power... But a bike's 1/5th to 1/10th the mass of a car. There's no room to install two or three mufflers in series like most cars have, each of which is physically bigger than the single muffler on a bike.

    (Edit: Not particularly entertaining and not exactly a rigorously precise comment, mind you. It is a bit of a challenge, though, as I found out in Formula SAE when designing our bike-engine'd car's exhaust system)
  10. If we want to get something published its probably better to seperate out the ideas, and send them in seperately. If column8 gets a flood of emails from bikers perspectives they are more likely to publish something. Try to make it amusing, only one main point and dont forget your name and where you come from.
  11. I think it's 3 Db, so yes that is twice as loud. Also what needs to be considered is the low frequency nature of some motorcycles. This registers in the human ear much more strongly than the Dba measurement scale which is used to comply motorcycles.

    I'm not sure this is a strong argument however as it indicates the law should be changed.
  12. My thinking is to ignore the twat's comment completely rather than to cause a fuss and sound like riders protesting way too much.

    Is this a debate we even want to have? It's a dumb premise, and quite possibly deliberately so, so don't take the bait.
  13. feel free to use this:

    That lawn mower of yours that you insist on using early Sunday mornings is louder than an average motorcycle, you dumbsh1t!
  14. Let's get a little more precise here on that point.

    +3dB is twice the sound wave pressure, but NOT twice as loud as perceived by the human ear. +4db is about 2.5x the sound wave pressure, but still not twice as loud.

    +10dB is twice as loud, as the human ear/brain perceives volume, and is, by very definition itself, the meaning of the decibel scale. +10dB is twice as loud to humans, because that's how the decibel scale was defined to be qualified.

    For anyone to state that motorcycles are 4x as loud, they are effectively stating that motorcycles are allowed a dB noise limit that is +20dB over that of cars. That is not true, that is not part of the ADR, and therefore this guy is just spouting garbage.
  15. More fun to continue the line that they've truncated in the on-line article...

    whining Fairfax journalists?

    miserable Column 8 readers?

    NSW politicians?

    Woolongong Netriders?

    The choices are endless :)
  16. I don't know what cars you guys own, but if its a reasonably small car, it will not come anywhere near the limit even under full noise. However, most bikes do get towards their legal limit, particularly as riders like to fit aftermarket exhausts. On top of that a motorcycle will spend much of it's time accelerating heavily, running close to the noise limit while a car will be doddling around at 40-60 on the same roads with little throttle. I would not be surprised to find out that many legal bikes are regularly 20dB above a standard car during typical use of both.

    Additionally, I'm not sure if it is only motorcycles that the guy is whinging about, odds are good he thinks the same about people who modify their cars. But at the end of the day, car enthusiasts are only a small portion of drivers, who use their car solely as a transport tool, where most if not all riders are enthusiasts and so much easier to point the finger at.

    Cheers for that I've been wondering the same thing. Useful bit of information to tuck away.
  17. Ah thanks, I was wondering why I've heard two different stories on this. Googling before my post about had the power at twice for 3dB.

    I've also heard it said that 3Db is considered a noticeably audible difference. (2dB being not enough to be definite)
  18. You people really aren't that bright, huh?
    Short and witty. Not longwinded and banal.
  19. +1dBA is meant to be at around the absolute limit for the "average" human to perceive any noticable increase in sound volume in a controlled environment.

    In the real world, +2dBA is, as you note, where most people will start pick up an increase in volume, and +3dBA is definitely louder.