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"Any difference between lower frequency 4 strokes and howling 2 strokes? "
Around here, the former irritate me longer, the howling 2 strokes (which as pointed out are more often now high rpm 4 strokes), because the screaming imports are gone out of earshot in a flash, heh heh. The "lower frequency 4 strokes" seem to have a need to sit at the stop sign en masse and rev their engines so us locals can envy then. :LOL:
 
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'84 CX650E that is evolving into a GL500
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I have something similar but I bought mine when they still had rotary switches. I was trained on how to take meaningful sound level measurements when I studied acoustics in college so I understand it's limitations and how to make consistent measurements; I would recommend researching this before you try to use the meter. The biggest mistake untrained people make is to not take into account the effects of distance and sound reflective surfaces. Without any reflecting surfaces doubling the distance will reduce the level measured by 3dB and halving it will increase the distance by 3dB. Reflective surfaces and enclosed spaces can have similar effects. You also should hold the SLM perpendicular to the ground (mic end pointing upward) whenever possible so that air pressure (wind) won't effect the reading.

And then there is the difference between dBA, dBB and dBC, all differently weighted frequency response profiles used for different types of measurement....
 

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'82 GL500 '83 GL650 '21 RoyalEnfield INT650
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Close to 50 on silverwing-40 on my 81 BMW R100
Paul (I am old & slow)
If I recall correctly, I got 52mpg on the spring ride on my GL650
The Interceptor has a smaller tank but better MPG so about the same range
But the INT650 has no reserve tank and a random fuel gauge.
 

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I need a gas station after 75 miles on my CX650 Custom with mikunis. Perhaps if it had louder pipes it would go further....
 

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I have something similar but I bought mine when they still had rotary switches. I was trained on how to take meaningful sound level measurements when I studied acoustics in college so I understand it's limitations and how to make consistent measurements; I would recommend researching this before you try to use the meter. The biggest mistake untrained people make is to not take into account the effects of distance and sound reflective surfaces. Without any reflecting surfaces doubling the distance will reduce the level measured by 3dB and halving it will increase the distance by 3dB. Reflective surfaces and enclosed spaces can have similar effects. You also should hold the SLM perpendicular to the ground (mic end pointing upward) whenever possible so that air pressure (wind) won't effect the reading.

And then there is the difference between dBA, dBB and dBC, all differently weighted frequency response profiles used for different types of measurement....

Thanks for that Bob. I've done a little reading on the use of this with regards to reading distance and deflection and will try to work out the best method I can come up with without leaving the yard. Having worked out the method I will then stay consistent to it.

Mrs. Phreak bought this because I think she thinks I have become obsessed with sound levels. She says she can only hear the thingy when I'm coming home when I get quite close so doesn't think it is as loud as I do.

I'll be back to baffles at some point in the future. I intend to try another set of bypass baffles but this time using larger internal pipe for greater gas flow. This will require dismantling a couple of these mufflers so that I can start with an empty shell rather than be working within a 48 mm pipe.

My concern is that while this approach will be freeer flowing it may be louder. I wonder if reduced diameter increases velocity and thus noise.
 

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'84 CX650E that is evolving into a GL500
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BTW: Reflective surfaces near the meter can give false readings as much as reflective surfaces near the subject being measured. Depending on how big your yard is I'd try to put the bike in the middle of an area of grass or other vegetation (the ground will be softer and less uniform there than say a driveway or siimilar where it would be packed & smooth or paved) and make the measurements from a location that is a bit closer to the bike than to any wall, fence &c.
 

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Thanks again Bob. I'll need to carefully select a spot and use it for all tests. My whole back yard is surrounded by sheet tin - sheds and fences - likely not ideal.

But consistent measurement methods will at least give consistent results so that improvements {or otherwise} can be tracked.

The official method here is to test at 3,500 RPM from a rear 3/4 angle from a given distance.
 

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'84 CX650E that is evolving into a GL500
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Yeah, that sounds like a standard developed by someone who doesn't understand that some engines run at 3500 RPM at in town speeds and others are halfway to redline at the same RPM.
 

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A f a g g o t is a bundle of sticks used for kindling, commonly abbreviated to "f a g", which is how the term became used for a cigarette (any pipe smoker will tell you cigarettes aren't good for much except lighting fires). How the term came to refer to a homosexual I don't know.
The reference to homosexuals goes back to a time period in England when they would be burned alive similar to bundle of sticks.
 

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'82 GL500 '83 GL650 '21 RoyalEnfield INT650
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Reminds me of a joke that went around years ago about a purely decorative Harley that wouldn't actually run but would have a sound system to make obnoxious exhaust noises.

Freebird: That could explain it.
 

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A f a g g o t is a bundle of sticks used for kindling, commonly abbreviated to "f a g", which is how the term became used for a cigarette (any pipe smoker will tell you cigarettes aren't good for much except lighting fires). How the term came to refer to a homosexual I don't know.
The tough guys used to make the weaker ones carry their cigarettes and so they called them "f a g boys". From there you can see how it become a slam on someone who wasn't actually gay. "What are you...his cigarette boy?!"
 

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I thing '***' got a lot worse than that in the English private schools.
What many think of as private schools (ie. not free, state-run schools), such as in Tom Brown's Schooldays, are actually called public schools...
There are also Approved Schools, but you had to be a very naughty boy to go to one of those...
 
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