In this post from several years ago, I discussed the process of changing rotor stops, or “bumpers” as they are sometimes called. It’s a fairly simple, if a little time consuming, process. In the article I mentioned purchasing my rotor stop material from Osmun music. Along with Osmun, there are many other great horn shops out there who sell the material in varying diameters, hardness (duro), and materials. However, another place to check out is the O-Ring Store, a wholesale retailer based in Idaho. Their O-Ring cord stock can be purchased by the foot, in Neoprene, Silicone, Buna-N, among other materials. It is extremely economical to buy rotor stop material this way, as long as you know the diameter you need for your horn, and the type of material you want.