A wider version of the Lock-In shape. Asymmetrical design with conical cut outside for less weight. Straight edge 'Lock-In' inside for control on all terrains.
Formula Four Urethane – Formula Four urethane is unlike any other. Both in the streets and under high-speed stress tests in Spitfire's lab, Formula Four wheels retained more material, coned less and kept their original shapes and sizes longer than any other wheel.