Rolling Resistance Calculator
Compare two setups to estimate rolling resistance (Crr).
How to Use
1. Perform two field tests (e.g., different tires) on a flat course (aim for a minimum of 2km for accuracy), recording average power, speed, and weight.
2. Ensure identical aerodynamic conditions: use the same body position, clothing, and equipment; test in low-wind conditions (<5 kph) or use an out-and-back course; conduct tests back-to-back to minimize environmental changes.
3. Enter data for Test A and Test B below. Air density and CdA are assumed constant for simplicity.
4. Click "Compare" to see Crr, power to overcome rolling resistance, time differences for a 10-mile time trial, and speed at a fixed power.
Limitations
This calculator assumes flat terrain, steady-state riding, and identical aerodynamic conditions (CdA and air density) between tests. Variations in rider position, wind, or surface conditions may affect accuracy. Results are estimates and only apply to the surface tested on.
Enter A/B Test Data
Test A
Test B
Weight of rider, all equipment, bike, etc., in kilograms.
Weight of rider, all equipment, bike, etc., in kilograms.