Wickerbill

A wickerbill is a small tab or lip attached to the trailing edge of a race car's rear wing or spoiler that increases downforce by disrupting airflow.

Think of a wickerbill as a tiny fence sitting on top of the rear wing of a race car. When air flows over the wing and hits this small vertical piece, it creates additional downward pressure on the car. This downward pressure, called downforce, pushes the car harder into the track, which gives the tires more grip and helps the car corner faster and stay more stable at high speeds.

Wickerbills are typically only a few inches tall, but their impact on a car's performance can be significant. The size of this aerodynamic device directly affects how much downforce it creates. A taller wickerbill generates more downforce but also creates more drag, which can slow the car down on straightaways. A smaller one produces less downforce but allows for higher top speeds.

Race teams use wickerbills as a tuning tool to adjust their car's handling for different tracks and conditions. On a tight, twisty circuit where cornering speed matters most, teams might use a larger wickerbill to maximize grip. On a fast oval track with long straightaways, they might choose a smaller one or remove it entirely to reduce drag and increase top speed.

These aerodynamic aids can be made from various materials including aluminum, carbon fiber, or other lightweight metals. They attach to the rear wing using bolts, rivets, or other mounting hardware, and some designs allow teams to adjust the angle or height between practice sessions or races.

In sprint car racing, sanctioning bodies like the World of Outlaws sometimes regulate wickerbill sizes to keep competition close and fair. NASCAR teams also use them extensively, making small adjustments to find the perfect balance between cornering grip and straight-line speed. The adjustments might seem minor, but in professional racing where victories are often decided by fractions of a second, these small aerodynamic tweaks can make the difference between winning and losing.

While wickerbills are most commonly found on rear wings and spoilers, some race cars also use them in other locations. For example, sprint cars sometimes have a small wickerbill on the hood in front of the driver to deflect dirt and debris away from the driver's helmet and visibility area.

The term "wickerbill" itself comes from the appearance of these devices, which resemble small wicker fencing when viewed from certain angles. Understanding how wickerbills work helps explain why race cars look the way they do and how teams constantly search for small advantages through aerodynamic refinement.