DBDirt Bike Finder
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Performance

Dirt Bike Top Speed Calculator

Estimate gearing-limited top speed in high gear at a given RPM. This is the speed the sprockets and tire will allow — not a drag-strip prediction.

Inputs

Crank to clutch basket

Rear tire overall diameter

Results
Live

  • Gearing-limited top speed

    81.52mph

  • Top speed

    131.19km/h

  • Overall ratio

    11:1

  • Sprocket final drive

    3.846:1

Formula

mph = (RPM × tire Ø in) / (overall ratio × 336)

Overall ratio = primary × gearbox × (rear sprocket ÷ front sprocket). Power-limited speed can be lower than this gearing limit.

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