GEAR CALCULATOR AFFINITY TRACK GEAR ROTATING CHARTRotating chart for making track related gear calculations simple Spin the perfect gear ratio, on the track or in the streets reliable, accurate gear calculations for (700c wheel) track bikes Affinity did the math and created a simple, easy to use chart which generates 100% accurate calculations unlike inaccurate online calculators Rotate the chart to choose your chain ring size, the window then displays the results of your chain ring & cog gear ratio