All About Gear Inches
In the days when 10-speed bikes really only had ten speeds, avid riders could reel off gear ratios by heart, as they were often switching out cassettes depending on their ride/race terrain. Now with the advent of 20(22? 30? 33?) speed drivetrains, a single cassette can easily accommodate adequate gears to cover most any ride.
Gear inches are very simple, a 53x11 gear pushes 126.6 inches of chain with one revolution. A 39x25 gear pushes 41 inches of chain. Short gears go uphill well, big gears provide max power.
The most common gear inch decision these days is when choosing between a standard or compact crankset. Compact cranksets became popular in the early 2000's when many riders started using them in Tour de France climbing stages. By offering slightly smaller front rings (usually 50-34), compact cranks offer more "usable" gears when the road tilts uphill. These smaller front gears are also very beneficial to recreational riders, who really don't spend that much time hammering across flat terrain, or launching break-neck sprints. Functionally, going compact trades a few top-end gear combos for a lot of mid-range ones.
A 50x11, 34x25 set up provides gear inches of 119.5 and 35.7, respectively.
For those who do race, a standard 53-39 setup will be most useful, as those Tour riders using compact cranks also had a team to shepherd them safely to the bottom of those climbs. Most racers I know have to chase their own breaks.
For all the gear inches information you could ever need, consult Sheldon Brown's Gear Ratio Calculator.
We carry Shimano, SRAM and Campagnolo cranksets. Most models are available as standard or compact cranksets. If you have any questions about component selection or finding that perfect gear, feel free to contact us at or sales@biketiresdirect.com.
