Is that true or it's just a reason to get new "sound" for your Bikes?. I have a set of CycleShack slip-ons on my Herritage, love the sound but after dozens of close call incidents, I just remove them and put the stock pipes back(my neighbor loves me more with stock pipes). To me, if the cage drivers has their windows down, then they'll hear me coming, but if they have their windows up and music/cell phone on, they will not hear me coming. I asked my lovely wife get in her Lexus and start the car up, leave everything in her Lexus the way it was like she is driving on the road(Window up,Auto Air and music on), and I fire up my Bike about 10feet behind her, rev it up around 2500-3000rpm and she said she has to listen for it to knows I'm behind there, same as my Daughter when she sat in her Honda with windows up and same as me when I sat in my Ram truck, and all of this is right on my driveway and not moving, I assume it's gonna be harder to hear when moving. You though.