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.
Buy Polar Accessories from Chain Reaction Cycles, the World's Largest Online Bike Store.
If you're not completely satisfied with an item you may return it within 12 months of purchase. We'll give you a full refund if the item hasn't been used or fitted.More information on returns