I do have a quick detach windshield on the bike. I have had the same thought about the noise reflection. Once again though, if it were something that I did not remove or replace, how would the sound be different now? And if it is the engine making that loud of a noise, like this past weekend, something must be terribly wrong. I really don't think it is the engine. The sound only shows up at the speeds stated before, and only if leaning. If I keep the bike dead straight up, no lean at all in either direction, there is no sound. As soon as there is even the slightest tilt, it shows up, but only at about 70 mph. I suppose I'll have to go through a process of elimination. I'm going to take a few pounds of torque off of the axle. If that doesn't work, I guess I will move on to the brakes. Then the tire, and so on.
I don't have to have fast, I just have to have fun!