A fixed gear ratio refers to the relationship between the number of teeth on the chainring (front sprocket) and the number of teeth on the cog (rear sprocket). Unlike geared bicycles, where multiple ratios can be selected, fixed gear bicycles have a direct 1:1 connection between pedalling and wheel rotation, meaning the ratio is constant.
The formula for Calculating Gear Ratio
The gear ratio is calculated using the following formula: Chainring/cog=
For example, if a bicycle has a 48-tooth chainring and a 16-tooth cog, the gear ratio is: 3
This means that for every full pedal revolution, the rear wheel turns three times.
This ratio is also important for working out skid patches, the secret is to make sure you have a prime number chainring here.
Gear Ratio Considerations
Choosing the right gear ratio depends on various factors, including your fitness level, experience, terrain, and intended use. Here are some common considerations:
Cadence and Speed
Higher gear ratios (e.g., 3:1 or 4:1) require more effort to start but provide higher speeds at lower cadences. Conversely, lower gear ratios (e.g., 2:1) make pedalling easier but require a higher cadence to achieve the same speed.
Terrain
- Flat Terrain: Higher gear ratios are suitable for flat terrain as they provide a smoother, faster ride.
- Hilly Terrain: Lower gear ratios are preferred for climbing as they reduce the effort needed to ascend slopes.
Riding Style
- Urban Commuting: A moderate gear ratio (e.g., 2.5:1 to 3:1) balances acceleration and speed.
- Track Racing: High ratios are used to achieve maximum speed on smooth tracks.
- Tracklocross and Trick Track Riding: Lower ratios allow for better control and balance.
Common Fixed Gear Ratios
Below is a chart illustrating common fixed gear ratios and their respective characteristics:
| Chainring Teeth | Cog Teeth | Gear Ratio | Suitable Terrain |
|---|---|---|---|
| 44 | 16 | 2.75 | Urban/Hilly/Tracklocross |
| 46 | 16 | 2.88 | General Use |
| 48 | 16 | 3.00 | Flat/Racing |
| 50 | 17 | 2.94 | Flat/Speed |
| 52 | 18 | 2.89 | Long-Distance |
How to Choose the Right Gear Ratio
To select your ideal gear ratio, you should consider your fitness level, the type of riding you plan to do, and your personal preferences, sometimes it is good to ignore all the advice; especially if you are on Reddit.

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