Sector 9 Butterballs are great for freeriding. 75a and 80a duro lets you roll over rough surfaces but easily initiate slides and drifts. The Cosmic Centerset Core gives the most amount of grip and even wear. A 38mm contact patch is wide enough for gripping but small enough for sliding. Rounded lips allows the wheel to break traction more easily and smoother from grip to slide. Butterballs are stone ground, which slide more easily than smooth wheels and don’t require a break-in period.