Formula Four: the heart of Spitfire wheels
If there’s one thing that made Spitfire famous worldwide, it’s the legendary Formula Four. This patented urethane blend is the result of years of research and testing with some of the best skaters on the planet. F4 wheels have become the gold standard because they combine three key features: speed, durability and control. They don’t flatspot, they don’t lose shape after a few sessions, and they keep a consistent board feel on any terrain – from smooth concrete to the roughest pavement.
Available in different duros (93A, 97A, 99A and 101A), Formula Four wheels let you choose between softer options for extra comfort and grip, or harder ones for maximum pop, speed and slide. And it’s not just the formula that matters: the shape also defines the profile of the wheel. Let’s break down all the Formula Four shapes and see which style of skating each one is best suited for.
Formula Four Classic

The most famous shape in skateboarding. Round edges, medium riding surface, versatile in every situation. It’s the ideal balance between control, speed and stability. Perfect for skaters who want a wheel that works everywhere – from street to park – without overthinking.
- Duro: 93A, 97A, 99A, 101A
- Sizes: 50–60 mm
- Best for: all-around skaters looking for a reliable wheel on any terrain.
Formula Four O.G. Classic

The very first version of the Classic shape, lightened with cutaway sidewalls. They offer a mix of stability and reduced weight, while keeping that old school feel loved by skaters who want durability and tradition.
- Duro: 99A, 101A
- Sizes: 51–60 mm
- Best for: skaters who love a classic ride and want extra resistance.
Formula Four Conical

A lightweight shape with cut-in sidewalls, designed for speed and slide control. Offers more riding surface than the Classic without adding weight. Ideal for technical tricks and fast grinds.
- Duro: 99A, 101A
- Sizes: 51–58 mm
- Best for: technical street, rail and ledge skating.
Formula Four Conical Full

A wider version of the Conical. More contact patch means more stability and more grip. Perfect for bowls, transitions and for skaters who want solid landings without sacrificing slide.
- Duro: 97A, 99A, 101A
- Sizes: 50–60 mm
- Best for: skaters who want solidity and control in every trick.
Formula Four Radial

Round edge with a medium riding surface. They combine the versatility of the Classic with a bit of extra width, making them more stable yet still quick and snappy. Great for skaters who switch between technical tricks and flowing lines.
- Duro: 93A, 99A, 101A
- Sizes: 48–58 mm
- Best for: street skaters who want stability without losing responsiveness.
Formula Four Radial Slim

The slimmer version of the Radials. Lighter, faster, and ideal for those who want a reactive, snappy setup. With less contact patch, they roll easier and give a sharper board feel.
- Duro: 97A, 99A
- Sizes: 54–60 mm
- Best for: technical street skaters looking for a lightweight setup.
Formula Four Radial Full

Extra-wide riding surface with round edges. Maximum stability and versatility, especially on open terrains like bowls and parks. Perfect if you want a wheel that provides confidence and smooth cruising.
- Duro: 97A, 99A
- Sizes: 54–60 mm
- Best for: bowls, transitions and fast cruising.
Formula Four Tablets

Straight-cut profile, reduced riding surface and minimal weight. The most reactive and fastest wheels in the Formula Four lineup. Perfect for skaters who love quick flips and instant changes of direction.
- Duro: 99A, 101A
- Sizes: 51–55 mm
- Best for: technical skaters and pure street skating.
Formula Four Lock-ins

Asymmetrical shape with a conical cut on one side for reduced weight and smoother slides, and a straight “lock-in” edge on the other to lock grinds with precision. Built for skaters who want control and security on rails and ledges without giving up speed.
- Duro: 99A, 101A
- Sizes: 52, 53, 54, 55, 57 mm
- Best for: technical street, stable grinds, reactive setups with solid lock-in.
Formula Four Lock-in Classic

A custom version designed with Ishod Wair. Keeps the asymmetrical Lock-In concept but with refined geometry for a more direct inside edge and faster response during transitions.
- Duro: 99A
- Sizes: 52, 53 mm
- Best for: technical skaters who want maximum precision on ledges/rails and a snappy pop.
Formula Four Lock-in Full

The wider variant of the Lock-In: conical cut on the outside for reduced weight, straight edge inside for a stronger lock. The larger contact patch offers stability and extra control on any terrain, from plazas to bowls.
- Duro: 99A
- Sizes: 54, 55, 57 mm
- Best for: skaters looking for grip and solid landings without losing lock-in functionality.











