Home / Lab / Gearing and chain

MotoWild Lab · Gearing and chain

Speed in every gear calculator (gear chart)

Road speed in all six gears at one rpm, from primary, gearbox and final drive ratios.

Units
rpm
Clutch teeth divided by engine sprocket teeth, e.g. 46/34 = 1.353.
Enter 0 for a five-speed gearbox.
mm

Result

Speed in 6th130.0 km/h
Speed in 1st50.0 km/h
Speed in 2nd68.4 km/h
Speed in 3rd86.7 km/h
Speed in 4th104.0 km/h
Speed in 5th118.2 km/h

How it is calculated, with your numbers
  1. Overall ratio, 1sto1 = primary × g1 × rear / front1.6 × 2.6 × 45 / 16 = 11.700
  2. Overall ratio, 2ndo2 = primary × g2 × rear / front1.6 × 1.9 × 45 / 16 = 8.550
  3. Overall ratio, 3rdo3 = primary × g3 × rear / front1.6 × 1.5 × 45 / 16 = 6.750
  4. Overall ratio, 4tho4 = primary × g4 × rear / front1.6 × 1.25 × 45 / 16 = 5.625
  5. Overall ratio, 5tho5 = primary × g5 × rear / front1.6 × 1.1 × 45 / 16 = 4.950
  6. Overall ratio, 6tho6 = primary × g6 × rear / front1.6 × 1 × 45 / 16 = 4.500
  7. Speed in 1sts1 = rpm / o1 × circ / 1000000 × 605,000 / 11.7 × 1,950 / 1000000 × 60 = 50.0 km/h
  8. Speed in 2nds2 = rpm / o2 × circ / 1000000 × 605,000 / 8.55 × 1,950 / 1000000 × 60 = 68.4 km/h
  9. Speed in 3rds3 = rpm / o3 × circ / 1000000 × 605,000 / 6.75 × 1,950 / 1000000 × 60 = 86.7 km/h
  10. Speed in 4ths4 = rpm / o4 × circ / 1000000 × 605,000 / 5.625 × 1,950 / 1000000 × 60 = 104.0 km/h
  11. Speed in 5ths5 = rpm / o5 × circ / 1000000 × 605,000 / 4.95 × 1,950 / 1000000 × 60 = 118.2 km/h
  12. Speed in 6ths6 = rpm / o6 × circ / 1000000 × 605,000 / 4.5 × 1,950 / 1000000 × 60 = 130.0 km/h

Working uses the metric units the formula is written in.

  • rpm Engine speed (rpm)
  • primary Primary reduction ratio
  • g1 1st gear ratio
  • g2 2nd gear ratio
  • g3 3rd gear ratio
  • g4 4th gear ratio
  • g5 5th gear ratio
  • g6 6th gear ratio
  • front Front sprocket or pulley teeth
  • rear Rear sprocket or pulley teeth
  • circ Rear tyre rolling circumference (mm)
  • o1 Overall ratio, 1st
  • o2 Overall ratio, 2nd
  • o3 Overall ratio, 3rd
  • o4 Overall ratio, 4th
  • o5 Overall ratio, 5th
  • o6 Overall ratio, 6th
  • s1 Speed in 1st
  • s2 Speed in 2nd
  • s3 Speed in 3rd
  • s4 Speed in 4th
  • s5 Speed in 5th
  • s6 Speed in 6th

What it means

Each gear's overall ratio is the primary ratio times the gear ratio times the final drive (rear teeth over front teeth). Divide the engine speed by the overall ratio for wheel rpm, and multiply by the tyre's rolling circumference for road speed. Doing all six at once shows the gaps between gears and where your cruising speed sits in top.

Many makers publish overall ratios rather than internal ones. To get an internal ratio, divide the overall ratio by primary times final drive.

Assumptions and limits

  • No clutch, belt or tyre slip.
  • Use the measured rolling circumference for the best accuracy; the tyre size gives the unloaded figure, a few percent more.

Sources

  • Foale, T., Motorcycle Handling and Chassis Design: The Art and Science, 2002.
  • Gillespie, T. D., Fundamentals of Vehicle Dynamics, SAE International, 1992.

Related calculators

Road speed in gear calculatorSpeed at any rpm from primary, gear and final drive ratios and tyre size.Cruising rpm calculatorEngine rpm at a given road speed in any gear.Belt drive pulley change calculatorHow far the rear axle moves, and how the gearing changes, when you fit different belt pulleys.

All calculators in the Lab →