Here is a baffle I made for a friend's XS650 that uses a slash-cut stock double-wall header pipe for the exhaust. The baffle is constructed of 3/4" trade size EMT (Electrical Metallic Tubing), also know as "thinwall." Three slots were cut into each end allowing me to bend out three wings on each end. You can cut two or four slots if you want to make two or four wings. Three 1/4" nuts and bolts have been put in each baffle for anti-reversion and to provide "back pressure." The nuts and screw-heads have been ground down a little for clearance. All wings are over-spread, and the baffle is forced and hammered into the pipe. Friction keeps the baffle in place. There is no need to screw or bolt it in. The baffle was made as long as possible, based on the straight length of the header that existed. On longer pipes, I have made baffles up to 14" long. The bike runs excellent, and was easy to tune. I am not an engineer, and I am not an expert on reversion or pipe design, but I know that baffles like mine lower the power band, and make a bike with short pipes a lot more enjoyable to ride in town. This bike runs great in all riding situations. This bike is still plenty loud. If you want to quiet it down, you can wrap fiberglass or Chore-Boy around the baffle before you insert it. I have made plenty of these home-made baffles for long pipes, but this was my first for short pipes. For long pipes you may only need a single screw and nut. EDIT: I rode this bike recently, and I know think that the 3 bolts in the baffle are too much. I'm trying to get the owner to pull the baffles and just use the last bolt. EDIT: The owner finally removed 2 of the bolts, just leaving the one closest to the end in, and bike runs even better than before. One thing, he has had problems with is the baffles blowing out. This has only been happening on bikes just running headers, so if that's what you are doing, then run a self-tapping screw through the baffle and pipe.