What is a motorcycle undersuit and why should you wear one? A motorcycle undersuit cools and protects the riders body from abrasion as it separates the skin from riding gear (leathers, mesh, textile) which can become sticky in hot weather. By inserting a moisture wicking cooling base layer between the riders skin and leathers, moisture is drawn away from the body, increasing circulation and flexibility during riding. Our high-tech motorcycle underwear reduces fatigue, soreness, and swelling while keeping the rider comfortable on hot weather motorcycle riding days. What do you wear under your leathers?