This video should be mandatory viewing for all of the influences who speak with such authority on the gated-manual vs. the F1-manual.
I had a Novitec Supersport muffler set on mine for a short time. Those things have 90 mm tailpipes vs OEM 72 mm and mine would wake the dead with the rest of the exhaust stock. The ones on the silver 575 are also 90 mm, so sound pretty good. Mine did not have valves and you could look all the way through the muffler on what would have been the valved side. On a 550 now, and I am sure the neighbors hate him. F1 works great if you know what you are doing and the system is well maintained. Trev's ministrations help.
