Spearit Kevlar® Constrictor Cord
Like most spearos, we used waxed Nylon lacing cord as constrictor for years. Why was it waxed anyway? The constrictor knot is punishing on the cord. To fully tighten the knot a large amount of tensile force must be applied and abrasion occurs as the outer loop(s) tighten on the inner hitch. The wax was applied to the nylon cord to lubricate it so that it could be tightened without breaking. Besides being weak the other problem was the stretch. Terminal beads and knots had to be larger to compensate for the stretchy constrictor. The problem with a larger bead is the constant stress on the rubber which has to stretch around it. This stress is why bands tend to break right over the wishbone bead. We wanted to use the smallest beads and knots possible so we knew we needed a better constrictor. Kevlar® fit the bill. its super strong ,so a constrictor knot or two will do the job. It is ultra low stretch so that when you tighten down your constrictor knot, it stays tight. Last, but not least, it is much better at retaining a knot than any other synthetic fiber. Say good bye to keeping a lighter around to melt a ball on the ends of your constrictor to control knot creep. With our Kevlar®² Constrictor you can cut it close and forget it or if an 1/8 inch tail offends your sense of perfection, tie an extra constrictor knot on top of the first and cut it off flush.
Choose a constrictor cord for the particular rubber diameter: