Most frames today are made from either Carbon Fiber, Lightweight Aluminum, or Polyurethane. Frames can range from different sizes going from 3 wheels to 5 five wheels. That is typically up to the skater, depending what size frame they prefer skating on. Most often the 3 and 4 wheel frames are the most popular because they offer the most stabilty, grip, and speed you need for races. The technology used in developing frames is changing very often so keep an eye out for the newest frame, because they will change your stride for the better!