Bike gearing tool

Gear Ratio & Cadence Calculator

Calculate your gear ratio, see speed at any cadence, and get triathlon-specific gearing recommendations.

Gear setup

Enter your chainring, rear cog, and cadence.

T

Front ring (e.g., 34, 50, 52)

T

Cassette cog (e.g., 11–32)

RPM

Your Speed

39.4 km/h

at 90 RPM

Gear Ratio

3.47

Balanced

Versatile gear range suitable for mixed terrain and most triathlon courses.

Speed at different cadences (52/15)

CadenceSpeed
60 RPM26.3 km/h
70 RPM30.7 km/h
75 RPM32.9 km/h
80 RPM35.1 km/h
85 RPMoptimal37.3 km/h
90 RPMoptimal39.4 km/h
95 RPMoptimal41.6 km/h
100 RPM43.8 km/h
110 RPM48.2 km/h

Triathlon gearing context

Sprint

Good all-around sprint gear. Target 90-95 RPM for efficient pacing.

Olympic

Solid Olympic-distance gear choice for most course profiles.

70.3

Maintain 85-90 RPM. This gear supports steady half-distance pacing.

Ironman

Keep cadence steady at 80-85 RPM to preserve run legs.

Practical recommendations

  • Maintain cadence between 85-95 RPM for optimal triathlon efficiency.
  • Lower cadence (80-85 RPM) can preserve run legs in long-course racing.
  • Practice gear shifts before race day to find your optimal combinations.

Informational tool. This calculator is for personal reference and gear-planning purposes only. Speed estimates assume ideal conditions (no wind, flat road, zero rolling resistance losses). Actual speed will vary based on terrain, wind, road surface, tire pressure, and rider position.

Methodology

How this calculator works

Gear Ratio & Cadence Methodology

Gear ratio and speed calculations use standard cycling physics: Speed = Cadence × Gear Ratio × Wheel Circumference. Triathlon cadence guidance draws on research showing 85-95 RPM as optimal for most athletes.

  • Use ISO-standard wheel circumference values for accurate speed calculation.
  • Separate gear classification into climbing, balanced, and high-speed ranges based on common cycling usage.
  • Frame cadence advice in triathlon context where run-leg preservation matters.

FAQ

Frequently asked questions

What is the ideal cadence for triathlon?

Research suggests 85-95 RPM for most triathletes on flat to rolling courses. Lower cadence (80-85 RPM) may help preserve run legs in long-course racing, though individual variation is significant.

How does gear ratio affect triathlon performance?

Higher gear ratios produce more speed per pedal stroke but require more force. In triathlon, grinding high gears can fatigue your legs before the run. A balanced gear selection for your course profile is key.

What gear setup is best for Ironman?

Most Ironman athletes benefit from a compact crankset (50/34) or semi-compact (52/36) paired with an 11-28 or 11-30 cassette. This provides enough range for flats and climbs while keeping cadence comfortable.

Evidence

References

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