So, the question stands, do they pass noise regulations? Are there noise regulations? Only in California?
I think even if they did pass a noise test (which is probably done at 75% throttle or something) then the stock ones are just annoying, but many owners take off the mufflers and run straight pipes that are just obnoxious. Sport bikes need to pass noise tests, thus the weird power curve dips now and the large mufflers. But the first thing riders do is take off the muffler, and bolt on a Ti or CF slip on cannister from Akropovic and there you go, 10 pounds of weight gone and sounds 100 hp faster. I like sport bikes though.
