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Gearing & Sprockets

Countershaft Sprocket Calculator

Changing the front sprocket is the fastest way to move gearing. See the equivalent rear-sprocket change and the percent effect.

Inputs
Results
Live

  • Gearing change

    8.33%

    Shorter — −1T front is a big hit

  • Stock ratio

    3.846:1

  • New ratio

    4.167:1

  • Equivalent rear on stock front

    54.2T

  • Front tooth change

    -1T

Formula

Equivalent rear ≈ stock rear × (stock front / new front)

Going down one tooth on the countershaft is roughly +8% gearing (shorter). Going up one is taller.

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