MTB Chain Length Calculator

Formula

The formula to calculate the MTB chain length is:

\[ \text{CL} = \left( \frac{\text{C} + \text{CR}}{2} \right) + \left( \frac{\text{CSL}}{25.4} \right) + 1 \]

Where:

\(\text{CL}\) is the chain length (links)
\(\text{C}\) is the number of teeth on the largest cog of the cassette
\(\text{CR}\) is the number of teeth on the largest chainring
\(\text{CSL}\) is the chainstay length (mm)

What is MTB Chain Length?

MTB chain length is the total number of links required to fit a mountain bike’s drivetrain properly. The correct chain length is crucial for efficient power transfer, smooth shifting, and preventing undue stress on the drivetrain components. An improperly sized chain can lead to poor shifting performance, increased wear, and potential damage to the bike.

Example Calculation 1

Let's assume the following values:

Number of Teeth on Largest Cog (C) = 42
Number of Teeth on Largest Chainring (CR) = 32
Chainstay Length (CSL) = 450 mm

Using the formula:

\[ \text{CL} = \left( \frac{42 + 32}{2} \right) + \left( \frac{450}{25.4} \right) + 1 \approx 37 + 17.72 + 1 = 55.72 \text{ links} \]

The MTB Chain Length is approximately 55.72 links.

Example Calculation 2

Let's assume the following values:

Number of Teeth on Largest Cog (C) = 50
Number of Teeth on Largest Chainring (CR) = 36
Chainstay Length (CSL) = 420 mm

Using the formula:

\[ \text{CL} = \left( \frac{50 + 36}{2} \right) + \left( \frac{420}{25.4} \right) + 1 \approx 43 + 16.54 + 1 = 60.54 \text{ links} \]

The MTB Chain Length is approximately 60.54 links.