The answer lies in aviation history. When the first airplanes were invented, flyers in the early open-cockpit planes were extremely vulnerable to the elements. Aviators quickly discovered that heavy, fleece-lined leather provided excellent protection from both wind and cold, while allowing adequate freedom of movement. German aviators in World War I were especially enthusiastic about this type of flight wear, and it soon became their standard apparel. The notoriety and flash of the expert German military fliers, as well as the practicality of the leather jacket, provided an attractive example that would soon lead to its almost universal adoption in military aviation.
And then came World War II. Cockpits were closed, but with planes that could fly far higher and faster, the need for protection from temperatures that would often drop to 30 degrees below zero was critical. The military was conscientious in supplying its flyers with leather jackets that provided adequate protection and were durable enough to withstand the rigors of combat.
During the war, many fliers discovered that there was an intense thrill in flying. So when the war ended, many flyers came home and took up the sport that seemed as close to the thrill of combat flying as they could get motorcycling. And what better protection for this sport than the leather jackets they had worn as fliers?
These former fliers formed motorcycle clubs together and the clubs came to be identified with their leather aviator’s jackets. Through the jackets, people recognized the riders as veterans, and viewed their jackets as badges of honor. The leather jacket thus became a symbol of pride, and the rider who wore it an object of admiration. Soon, all riders wanted to have similar badges of honor, and having acquired their own leather jackets, they quickly recognized their assets as protective gear. Thus for reasons of image and utility they became the standard gear of the motorcyclist. And although styles have changed over the years, the reasons for wearing a leather jacket, society’s image of the adventurous spirit, have not.