If you had to pick a wheel to put on anyone's skateboard, you'd do very well with a set of Spitfire Formula Four 99d Classics Skateboard Wheels. Unbeatable durability in a time-tested all-round shape, chances are your favorite pro is riding these.
Classic Shape–The #1 shape in skateboarding worldwide - proven for speed and control.
99a Durometer–More speed and control on all surfaces. Unmatched flatspot resistance. Smooth, anti-stick ride. High-rebound compound.
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.
High Rebound Compound
| SIZE | WIDTH | RIDING SURFACE |
| 50MM | 30MM | 14.5MM |
| 51MM | 31MM | 15MM |
| 52MM | 32MM | 15.5MM |
| 53MM | 33MM | 16MM |
| 54MM | 33.5MM | 16.5MM |
| 55MM | 35MM | 17.5MM |
| 56MM | 35.3MM | 17.8MM |
| 58MM | 35.8MM | 18MM |
| 60MM | 33.9MM | 21.5MM |
