Allows you to select the right gears for your bicycle. GearCalc enables you to get answers to the folowing questions: Do I really need a nine cog cassette? Do I really need a triple chainring? How many of my 27 gears are unique and how many are duplicates? How much will my cadence drop when I change up? What is the ideal speed (and cadence) for each gear change? What metre ratio is equivalent to an 86-inch ratio? What is the most efficient route through my gears? Which freewheel/cassette is best for my needs? How can I design a better gear set? and more. You can assess and calculate wheel diameters, cadence minimums and maximums, the number of teeth needed for each chainring and freewheel, and display gear usage tables. You can also generate graphs depicting speed by gear number (freewheel), and the effect of every change over the whole system. In addition, you can print a certification for your bike.