Bones SPF P5 Sidecuts 81B Skateboard Wheels The Bones SPF P5 Sidecuts 81B Wheels are built for fast, responsive skating on smooth skatepark surfaces. Bones Skatepark Formula(TM) uses high-rebound urethane designed to resist flatspotting and abrasion while maintaining the grip and slide needed for park skating. The P5 Sidecut shape provides a versatile profile for transition, bowls, and other skatepark terrain. Available in 54mm and 58mm sizes, both options use a hard 81B formula, equivalent to 101A. Details Formula: Bones Skatepark Formula(TM) (SPF) Shape: P5 Sidecut Durometer: 81B (101A) 54mm Size: 54mm diameter x 31mm width 58mm Size: 58mm diameter x 33mm width Surface: Smooth Suggested Use: Skateparks Color: White Features: High-rebound urethane formulated for fast roll, flatspot resistance, abrasion resistance, grip, and slide