Sitting here at Tim's with my sunrise cuppa Joe and witnessed two big, quiet motorcycles passing down the blvd in front of me. One was even a sport bike. Both with stock exhausts. ......quiet and classy sounding!
Watched a good video recently, from a well respected motorcycle vendor, dealing with aftermarket exhausts. Interesting. The advice was, for street use - keep the stock exhaust system. Modern bikes have well engineered exhaust systems, for power, mpg's, driveability, etc., etc.
Thinking a loud pipe on a street bike will improve anything....is old fashioned thinking was his take away.
But, kids 9 to 90 love the noise....so they'll keep buying them.
Stig