There are a range of factors that can affect your cycling speed. Obviously fitness is one of them, however, weather conditions and the varying gradients of the road play a huge part too. The most advanced way of measuring how these factors affect your performance speed is with the aerodynamic Wireless Polar CS speed sensor.  

• Measures your current, average and maximum speeds
• Track your average speed to see your progress and performance improve
• Light yet tough, and easy to attach