Spitfire Formula Four 99D LOCK-IN Skateboard Wheels - 53mm

The Spitfire Formula Four (F4) 99D Lock-In 53mm is a specialized skateboard wheel designed for riders who prioritize control and precision during grinds.

Key Features & Performance

• Asymmetrical Lock-In Shape: Features a straight-edge inside wall that "locks" onto rails and coping for more stable grinds, paired with a conical-cut outside wall to reduce weight and assist with flip tricks.
• 99D Durometer: Offers a balanced hardness that provides more grip and a smoother ride on rough surfaces compared to the harder 101D version, while still maintaining high speed and "slide on demand".
• Formula Four Urethane: Known for its industry-leading flatspot resistance and durability, ensuring the wheels maintain their shape and size even under heavy abuse.
• 53mm Diameter: A versatile mid-size ideal for a mix of street and park skating, providing a good balance between acceleration and maintaining speed.