What does "wheel hardness" mean?
Simply put, wheel hardness is how hard or soft the wheels of your skateboard or longboard are. Different hardness levels provide different rides: Softer wheels (75a-80a), often found on longboards, offer a smoother ride with more grip. Harder wheels (99a-101a) on skateboards make for a rougher ride but are better for skateparks.
Wheel hardness is measured by a durometer, an instrument used to measure the hardness of rubber or plastics. The hardness is then assigned a numerical rating along with a durometer rating in the following types: A, B, C, D, DO, E, O, OO, and OOO.
