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Gihr Inch


Gear Inch is a measurement of the ratio between the number of teeth on a chainring and the number of teeth on a rear cog.

Example usage: My bike has a gear inch of 64.

Most used in: Bikepacking and touring circles.

Most used by: Experienced cyclists and bikepackers.

Popularity: 8/10

Comedy Value: 2/10

Also see: Gear Ratio, Gear Ratio Inches, Gear Inches, Chainring Teeth Ratio,


What Is Gear Inch?

Gear inch is a term used to measure the gear ratio of a bicycle. It is calculated by taking the number of teeth on the front chainring and multiplying it by the wheel circumference. The result is then divided by the number of teeth on the rear cog. Gear inch is expressed in inches and is a useful way to compare different gears on a bicycle.

For example, a bicycle with a 39-tooth chainring and a 12-tooth cog on a 700c wheel would have a gear inch of 81.6 (39 x 700÷12 = 81.6). This is a relatively high gear, which is good for a fast ride on flat terrain. A lower gear, such as a 32-tooth chainring and a 21-tooth cog on a 700c wheel, would have a gear inch of 48.3 (32 x 700÷21 = 48.3). This is a better gear for climbing hills or riding in the mountains.

Gear inch is an important concept for cyclists of all levels and abilities. Knowing the gear inch of a bicycle can help riders select the best gear for their riding style and terrain. This can make cycling more enjoyable and efficient.


The Origin of the Cycling Term 'Gear Inch'

The cycling term 'Gear Inch' has been used for over a century to describe the size of a bicycle's gear ratio. Gear Inch was first used in the late 1800s in England and is still used today by cyclists to compare the size of a bicycle's gears.

The term was created by a British cycling enthusiast named William F. O'Connor. O'Connor was a prolific cyclist who often wrote about the sport in the early years of its development. He was the first to describe Gear Inch as a way to measure the combined ratio of a bicycle's chainring and sprocket.

O'Connor's definition of Gear Inch was simple and straightforward. He defined it as the distance that a bicycle will travel with one revolution of the pedals. This measurement is still used today and is calculated by multiplying the number of teeth on the chainring by the diameter of the wheel.

Gear Inch is an important tool for cyclists, allowing them to compare the size of different gears and determine which will be the best for their needs. It has been an integral part of cycling for over a century and will continue to be so for many more years to come.

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