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Gear Ratio Formula:
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The Sheldon Brown gear ratio calculation provides a standardized way to compare bicycle gearing across different wheel sizes. It's calculated by multiplying the chainring-to-cog ratio by the wheel diameter, giving a numerical value that represents the effective "gear inches."
The calculator uses the Sheldon Brown gear ratio formula:
Where:
Explanation: This calculation gives you the distance the bicycle travels with one complete pedal revolution, measured in gear inches.
Details: Understanding gear ratios helps cyclists choose appropriate gearing for different terrain, optimize pedaling efficiency, and compare gear setups across different bicycles.
Tips: Enter the number of teeth on your chainring and cog, plus your wheel diameter in inches. All values must be positive numbers.
Q1: What is a typical gear ratio range?
A: Most bicycles have gear ratios between 20-120 gear inches, with lower numbers for easier climbing and higher numbers for faster riding on flat terrain.
Q2: How does wheel diameter affect gear ratio?
A: Larger wheels effectively create higher gearing, meaning you'll travel further with each pedal revolution compared to smaller wheels with the same chainring/cog combination.
Q3: What's the difference between gear ratio and gear inches?
A: Gear inches is the result of the Sheldon Brown calculation and represents the effective diameter of the drive wheel if it were directly driven by the pedals.
Q4: Why is it called "Sheldon Brown" gear ratio?
A: Named after Sheldon Brown, a renowned bicycle mechanic and technical expert who popularized this standardized method of comparing bicycle gearing.
Q5: How accurate is this calculation for different tire sizes?
A: For precise calculations, use the actual measured diameter of your wheel with tire inflated, as different tire sizes can significantly affect the final result.