The "speed bump" is to protect the part of the ferrule sleeve that is exposed--i.e., not covered by wraps or epoxy. The idea is to protect that part of the graphite from wear or fractures. Not critical in a small stream rod, but on a rod which generates higher line speeds and may use more abrasive lines, it can help. I got the idea from the guy who makes Fetha-Styx--a sponsor of this site. Nice guy with some cool ideas. He also puts a fighting butt on ALL of his rods to protect the butt cap of the reel seat.