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Gear Inches Formula:
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Gear inches is a measurement that combines the bike's gear ratio with wheel diameter to give a single number representing how "hard" or "easy" a gear is to pedal. It allows direct comparison between different bike setups.
The calculator uses the gear inches formula:
Where:
Explanation: Higher gear inches mean more distance traveled per pedal revolution (harder to pedal), while lower numbers mean less distance (easier to pedal).
Details: Gear inches help cyclists choose appropriate gearing for terrain, compare different bikes, and optimize pedaling efficiency. Mountain bikers particularly benefit from understanding gear inches when selecting components for technical terrain.
Tips: Enter your gear ratio (chainring teeth ÷ cog teeth) and your wheel diameter including tire (in inches). Typical mountain bike wheel diameters range from 26-29 inches depending on wheel size and tire thickness.
Q1: What's a good gear inch range for mountain biking?
A: Trail bikes typically range from 20-100 gear inches, with lower values better for climbing and technical terrain.
Q2: How do I measure my wheel diameter?
A: Measure from ground to wheel axle, double that measurement, and add tire height (or measure directly with tire inflated to riding pressure).
Q3: Why use gear inches instead of just gear ratio?
A: Gear inches account for wheel size differences - a 2:1 ratio feels very different on a 26" wheel vs a 29" wheel.
Q4: What's the relationship between gear inches and speed?
A: Higher gear inches allow higher speeds per pedal revolution, but require more force to turn the pedals.
Q5: How does tire pressure affect gear inches?
A: Lower pressure slightly decreases effective wheel diameter, but the difference is usually negligible for gear inch calculations.