Detail SPITFIRE formula four classic green 52mm 101duro skateboard wheels original
Spitfire Formula Four Classic 101a Skateboard Wheels are a hard and fast 52mm wheel in Spitfire's premium F4 formula
Wheel Shape / Profile: Classic - Spitfire claim this is the #1 shape in skateboarding worldwide. And it probably is. This shape first emerged in the early ’90s and has been a popular go-to ever since. It features a large radius from the bearing seat which produces a fairly narrow contact patch. It is a great all-rounder. For more info read Spitfire Wheel Shapes Explained
Urethane - Formula Four 101a: Spitfire released their new Formula Four wheels a few years ago now. The latest formula was designed for higher abrasion resistance. This means it is a little harder to flat spot. Usually adorned with a red coloured graphic, the Formula Four 101A wheels are the hardest Spitfire Wheels available. They are super fast on smooth surfaces and the easiest to slide. Being super hard, if you find they let go on smooth surfaces or feel unpleasant on rougher terrain, switch back to the 99A models. There are no hard and fast rules, best to try out different wheels and select what works best for you. For more info read Spitfire Wheel Formulas Explained