Spitfire Formula Four Lockins 99a Skateboard Wheels are the newest wheel from Spitfire. These asymmetrically shaped wheels give you more control at speed, so you can lock in your 5-0 grind around the whole bowl! Tested by Spitfire Team riders, Formula Four Performance Urethane lasted longer, withstood more abuse and performed superior to all other wheels.
Wheel Size - 53mm, 55mm, 57mm
Wheel Shape / Profile: Lock Ins - Looking for the best of both worlds, then the newer shaped Lock Ins are for you. It’s an asymmetrical shape, meaning it has a different shape on each side. A flatter side for locking into edges and a chamfered side that won’t catch when sliding so you can lock in your 5-0 grind around the whole bowl!
Urethane - Formula Four 99A: 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. Formula Four 99A wheels are generally decorated with a blue themed graphic. Unless of course it is one of the signature wheels. The signature wheels feature artwork custom designed for each rider. 99A is considered a softer wheel in the modern skateboarding scene. They are still very hard. The 99A formula will provide a little more grip on super smooth surfaces and is a little more forgiving to ride on rougher surfaces..