The Spitfire Formula Four 101D Conical Full 53mm Skateboard Wheels are engineered for the skater who demands the hardest, fastest, and most resilient urethane available. Spitfire's Formula Four 101D compound is the pinnacle of wheel technology — rock-hard at 101 Durometer, flat-spot resistant under repeated power slides, and built to stay round session after session. At 53mm in the Conical Full shape, these wheels deliver maximum contact for grinds while staying snappy for street and park skating.

• Formula Four 101D Urethane: Spitfire's hardest, fastest compound — 101 Durometer for maximum roll speed on smooth surfaces with exceptional flat-spot resistance under repeated slides and grinds
• Conical Full Shape: Wide, full contact patch across the entire wheel width for maximum surface on grinds and rails while maintaining a lightweight, snappy overall profile
• 53mm Diameter: Ideal sizing for technical street skating and all-around park performance — large enough for consistent roll speed, small enough for quick flip tricks and technical footwork
• Flat-Spot Resistant: Formula Four compound holds its shape under hard power slides and repeated friction — outlasts standard urethane formulas in longevity and consistency
• Best For: Technical street skating, park skating, ledge grinds, rail slides, and riders who prioritize maximum speed and durability over grip

Setup Note: At 101D, these are hard wheels optimized for smooth surfaces — skatepark concrete, marble, granite ledges. On rough asphalt, consider stepping down to 99D for more grip and vibration absorption.