Drafting (aerodynamics)

Lore & Background

Drafting is used to reduce wind resistance and is most commonly seen in bicycle racing, motorcycle racing, car racing, and speedskating, though it occasionally appears in cross-country skiing, downhill skateboarding, and running. In swimming, drafting occurs in both open-water races and traditional pool races, where a swimmer may hug the lane line to take advantage of the liquid slipstream in another swimmer's wake. It is believed, but not conclusively proven, that thoroughbred racing horses draft each other, especially in longer races.

In cycling, any time one bicyclist rides behind another, energy is conserved, especially at higher speeds. The main group of tightly packed cyclists in a road race is called a peloton, where each rider except the first drafts behind others. A fast-riding paceline may employ a 'Belgian tourniquet,' where each cyclist successively leads the group. Drafting can be cooperative, with competitors taking turns in the lead position, or tactical, where a follower conserves energy for a breakaway push to the finish.

In motorsport, drafting is used in single-seater open-wheel series such as Formula One and IndyCar, as well as in stock car racing. On faster speedways used by NASCAR and ARCA, two or more vehicles can race faster when lined up front-to-rear than a single car alone. The 'slingshot pass' is a dramatic maneuver where a trailing car uses the lead car's wake to pull up with maximum momentum and pass. Bump drafting, a tactic at Talladega and Daytona, involves the following car bumping the lead car to maintain momentum; if done roughly, it can cause crashes, leading NASCAR to implement restrictions.

Reader's Guide

Drafting is a fundamental aerodynamic technique that has shaped competitive sports, particularly those involving high speeds. Its significance lies in its ability to conserve energy and increase speed through cooperative or tactical positioning. In cycling, drafting enables the formation of pelotons and pacelines, allowing riders to share the workload and achieve higher average speeds. In motorsport, drafting has been a game-changer, most notably discovered during the 1960 Daytona 500, where Junior Johnson used it to overcome his car's performance deficit. The technique evolved into bump drafting and tandem drafting, which dominated races at restrictor plate tracks like Daytona and Talladega, leading to speeds 15 mph faster than single cars. However, drafting also introduces challenges, such as 'dirty air' in open-wheel racing, which reduces grip for trailing cars, and 'aero push' in NASCAR, which can decrease overtaking. The legacy of drafting extends beyond racing: Nike's Breaking2 project used pacemaker formations to minimize drag for runners, and experts predict cooperative drafting could improve running times. Drafting remains a critical strategic element, balancing cooperation and competition, and continues to influence vehicle design and race tactics.

Did You Know?

• Drafting has been known and used in motorsport and other sports long before 1960.
• In cycling, a fast-riding paceline may use a 'Belgian tourniquet,' where each cyclist successively leads the group.
• Bump drafting was popularized in NASCAR, particularly at Daytona and Talladega, in the early 2000s.
• At the newly paved Daytona International Speedway in 2011, two-car drafting allowed cars to run around 5-10 mph faster than single cars.