No official sound check, but an overly obnoxious bike will not be allowed to run. It can't idle at 110db. That is in the obnoxious territory at full throttle. If it has the stock KTM silencer, it will be fine. I'll throw this out at you. Right now I plan on riding my mountain bike on the DS run. So if you'd rather pedal, you can ride with me, if you don't mind waiting for me.