On Thu, 20 Jul 2017 12:10:52 -0700 (PDT),
trader_4 wrote:

There is also the saying that loud pipes save lives.

Looking up the most common types of fatal motorcycle accidents, it seems
that cars almost never rear end a motorcycle (5%).

About three quarters of the fatal accidents occur as head-on collisions,
with the other quarter being mostly the motorclists losing control of their
bike on their own.

Half of the accidents are when cars turn left into the motorcyclist.
http://www.nolo.com/legal-encycloped...ses-30330.html

There's nothing there about loud pipes but obviously visibility is always a
critical factor.

If you look at common causes of crashes, almost none of them would be
avoided by loud pipes (e.g., losing control of the bike).
https://www.bestmotorbikejackets.com...cle-accidents/

I don't know if that's true or not, but it seems logical that
drawing attention to the fact that a MC is there, is a benefit,
because most of the car and bike accidents occur when the car
driver for whatever reasons, behaved like the bike never registered
in their mind.

I did a quick skim of the common types of motorcycle accidents
http://www.mackesysmye.com/articles-...ycle-accidents
https://www.habbaspilaw.com/5-common...cle-accidents/

Where most, if not almost all of them, wouldn't make any difference with or
without loud pipes. Given that light moves faster and further than sound
(so to speak), one has to wonder if someone doesn't "see" you coming the
other way (which is the most common and most dangerous crash), are they
really going to hear you while they're in their luxurious cage?

Doubt it.
But I'm open to research that says otherwise.

It's interesting that I looked at about a dozen articles, almost all of
which suggested how to avoid the accidents, where none suggested loud
pipes.
https://rideapart.com/articles/10-co...-to-avoid-them

Of course, there are plenty of articles titled
"Do loud pipes save lives"
https://motorbikewriter.com/challeng...-pipes-theory/
http://motorcyclesafetynews.com/?p=878
http://motorcycleintelligence.com/do...ve-lives/1119/
https://www.autoevolution.com/news/m...t-1-45969.html

Yikes! Look at just that *last* article.
"The truth behind such a claim disproves this myth on so many levels:
simple, common physics, common sense or plain reason can bring in countless
reasons because this is just a myth. Let's tread the path of physics a bit
and analyze what's happening from a strictly mechanical point of view."

You can read them, but I skimmed them, with the result being it's a myth.