Last month we talked about wheel size in relationship to rollability. Big wheels, assuming they are sized properly for the application, are easier to roll than small wheels. Today we’ll look at the tread material, where the rubber meets the road. (I apologize for that).
Wheels come with a variety of tread materials: Forged Steel, Cast Iron, Phenolic, Polypropylene, Polyurethane, Thermoplastic Rubber, Neoprene Rubber, Mold-on Natural Rubber, just to name a few. We could spend days going over the advantages, disadvantages, concerns, and general properties of each tread material; we like wheels. But to spare you, and hopefully keep your attention, we’ll stick to the basics. For most caster users, it’s not important to know each wheel and each wheels unique characteristics. We can group this in two ways: Tread Hardness and Tread Flatness.