Enter the number of teeth on the front ring, rear cog, and the diameter of the wheel into the calculator to determine the gear inch.

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## Gear Inch Formula

The following is the gear inch formula:

GI = TFR / TRC * D

- Where GI is the gear inch
- TFR is the number of teeth in the front ring
- TRC is the number of teeth in the rear cog
- D is the diameter of the wheels (inches)

## Gear Inch Definition

A gear inch is defined as the ratio of the teeth in the front ring divided by the rear cog times the diameter of the wheel.

## What do gear inches mean?

Gear inches are a way of describing the mechanical advantage of different gear settings on a bike. The higher the gear inch the greater the mechanical advantage provided from the petals to the wheels.

## How do gear inches work?

Gear inches work by the difference in teeth of two different cogs in a bike system. The greater the difference between the two cogs the greater the gear inch and the more advantage gained by the biker.

## What is a good gear inch?

A good gear inch depends on the biking conditions. For downhill conditions, you may want a lower gear inch so that you can petal an optimal speed, and vise versa for climbing a hill.

## How to calculate gear inches?

- First, determine the number of teeth in the front cog. Measure or count the total number of teeth in the front cog. For this example, we will say this is 10.
- Next, determine the number of teeth in the rear cog. For this example, we will say this is 5.
- Next, determine the diameter of the wheel. We will assume a 35″ tire.
- Finally, calculate the number of gear inches using the formula above. So, (10/5)*35 = 70 gear inches.