Skateboard Design: Tail Angle and Radius

Note: at the time of this article, there is not a clear industry standard for skateboard dimensions. This article presents the “SK8CAD” Standard; please note that other manufacturers and distributors may use alternative definitions than those presented here.

If your board has an angled kicktail, it is defined by two parameters: an angle and a radius. The “tail angle” defines how steep the kick ultimately gets, and the “tail radius” defines how quickly it gets steep.

A steeper angle means that the board’s kick is closer to being vertical. A smaller radius means the kick bends to that angle more tightly, for example, a really small radius would feel like the board is simply kinked or sharply bent into the angle, while a very large radius would feel more bowl-like. The larger the angle and the smaller the radius, the steeper the board will feel.

21 degree tail angle with 4 inch radius.

14 degree tail angle with 4 inch radius. Notice the tail is less steep and doesn't rise as high as in the previous image.

21 degree tail angle with 10 inch tail radius. Notice how it has more of a curved shape than the previous images.

Steepness increases the pop angle of the board, which is the angle the board makes with the ground when popping up an ollie. Steeper pop angles usually help you pop a little higher. A steeper kicktail with a tighter kick radius will also help lock in your back foot just before the kick begins, which can help with stability when maneuvering your board.

A smaller angle and larger radius will make the board feel less steep and reduce the pop angle. A lower pop angle usually helps the board feel more responsive as it will pop faster, since it’s closer to the ground.

Angles and kick radii also play a role in other board dynamics, like truck stands, rail flips, caspers and other freestyle tricks that involve using the board in more ways than just with its wheels on the ground.

Ultimately, you'll want to try different combinations of tail angles and radii to determine what you like to ride best. You can use the flow chart below as a starting point. Keep in mind, if you're designing a mold to press boards using the traditional method with 1/16" maple and glue, you'll likely see a bit of “spring back” - the bends will flatten out slightly. (A reduction in kick angle of around 1°-1.5° seems common, but this can vary based on your process and geometry.)

Typical tail angles and radii:

Street decks: 18° - 21°, 4" - 5"

Transition decks: 17° - 21°, 4" - 7"

Longboards (dancing): 10° - 16°, 4" - 9"

Longboards (downhill): 0° - 21°, 4" - 6"

Surf skates: 14° - 21°, 4" - 6"

Cruisers: 0° - 21°, 4" - 6"

Freestyle: 12° - 19°, 4" - 9"

Recommended ranges for goals:

Maneuverability (flip tricks, pivoting, quick movements): 18° - 21°, 4" - 6"

Stability: 18° - 21°, 4" - 5"

Dancing: 10° - 16°, 4" - 9"

Pop: 19° - 21°, 4" - 5"

Speed: 0° - 21°, 4" - 6"

Start designing: https://sk8cad.com

Skateboard Design: Tail Angle and Radius

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