Spitfire Grimple Stix Formula Four Skateboard wheels - Lock-In Full - 99 Duro

Built for chaos, control, and everything in between, the Spitfire Grimple Stix Formula Four Lock-In Full 99a wheels deliver smooth speed, precise slides, and unmatched durability. Crafted with Spitfire’s legendary Formula Four urethane, they resist flat spots and maintain roll under heavy use, giving you confidence session after session.

The Grimple Stix graphics are from the hand of self proclaimed Aesthetic Assasin, Lou Barberio. Find more of his work on Instagram: @grimplestix @_helhound_

The Lock-In Full shape features a wide riding surface with an asymmetrical cut - rounded on the outside, squared on the inside - locking you into ledges, rails, and coping with maximum control. Designed for skaters who push hard and demand precision.

Available Sizes: 54mm, 55mm, 57mm
Durometer: 99a
Shape: Lock-In Full, a wider version of the Lock-In shape. Asymmetrical design with a conical cut outside to reduce weight. Straight edge "Lock-In" profile on the inside for control on all terrains.
Formula: Formula Four Urethane – smooth, fast, and long-lasting

Ride harder. Lock in. Roll Spitfire.

About Spitfire Wheels

Founded in 1987 by pro skater Jim Thiebaud and entrepreneur Fausto Vitello in San Francisco, Spitfire quickly became a cornerstone of skateboarding. Known for durable, high-performance wheels and their iconic flaming skull “Bighead” logo, Spitfire helped define street and park skating in the late ‘80s and ‘90s.

Innovation has always been at the core of Spitfire. From early urethane formulas that resisted flatspotting to today’s Formula Four line—renowned for speed, smoothness, and longevity—the brand keeps pushing what skateboard wheels can do.

Part of Deluxe Distribution, Spitfire continues to roll with legendary pros and rising talent alike, creating wheels, graphics, and products that capture skateboarding’s raw, creative spirit. When you ride Spitfire, you’re rolling with heritage, performance, and that unmistakable fire under your board.