Any bike that you have to think for a second "Is that too loud", is. How many riders are really so very good, that their engines are so built up, that they have to have a loud pipe? Too many (99.99%) buy a pipe just to be loud/noticed/blingy. Here on TT, questions are posted all the time "Do I need to rejet with my 110Db super pie?" Often, I would like to say yes, go down three jet sizes" but sadly, it will not cause a melt down like it would on a 2S. Do these people really need the pipe" Answer honestly. My WR has a stock system, it seems pretty damn quiet to me. Bike is plenty fast enough. I could port, cams, big bore and get more power, if I really needed it. Then, when I am paid the big bucks to ride factory (yrah....) then a loud pipe might be OK, if the AMA allows it.... For my SM, I have two engines, one semi stock, the other worked. The semi stock engine, I run a stock exhaust. The fully worked engine, a Yosh Ti (stupid loud). The worked engine is only run in an appropriate environment.