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Gearing & Sprockets

Dirt Bike Sprocket Calculator

See how a front or rear sprocket change moves final drive, acceleration, and theoretical top speed.

Inputs
Results
Live

  • New final drive

    4:1

  • Stock final drive

    3.692:1

  • Gearing change

    8.33%

    Shorter — punchier off corners

  • Speed at RPM (new)

    71.26mph

  • Speed at RPM (stock)

    77.19mph

  • Speed difference

    -5.94mph

Formula

New ratio = new rear ÷ new front · Speed change ≈ stock ratio / new ratio

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