Example Data Table
| Setup |
Mass |
Crr |
Surface |
Speed |
Rolling Force |
Rolling Power |
| Road race tire |
82 kg |
0.0035 |
1.00 |
32 km/h |
2.81 N |
25.02 W |
| Commuter tire |
95 kg |
0.0060 |
1.00 |
25 km/h |
5.59 N |
38.83 W |
| Gravel tire |
92 kg |
0.0100 |
1.30 |
20 km/h |
11.73 N |
65.15 W |
Formula Used
Weighted Crr: Crrw = Front Crr × Front Load × Front Pressure Factor + Rear Crr × Rear Load × Rear Pressure Factor
Pressure Factor: Pf = (Reference Pressure ÷ Actual Pressure)Pressure Sensitivity
Effective Crr: Crr = Crrw × Surface Factor × Temperature Factor
Rolling Force: Frr = Crr × m × g
Rolling Power: Prr = Frr × v
Trip Energy: Wh = P × Time Hours
Battery Range: Range = Usable Battery Wh ÷ Wh per km
How To Use This Calculator
Enter the total mass of rider, bike, luggage, and accessories.
Add your planned speed and trip distance.
Enter front and rear tire Crr values.
Use measured tire data when available.
Set the front load share for your riding position.
Choose surface and temperature multipliers for the route.
Add tire pressures and reference pressure for comparison.
Enter battery details when checking e-bike energy use.
Press calculate and review force, watts, energy, and range.
Bike Tire Rolling Resistance Guide
Why Rolling Resistance Matters
Rolling resistance is the force that slows a bicycle as tires deform on the road. It is small, but it matters. At racing speed, a few watts can decide comfort, range, and pace. For an e-bike, those watts also reduce battery distance.
Main Inputs
The main input is total system mass. This includes rider, bike, bags, water, and accessories. More mass increases normal force. Normal force increases rolling drag. The coefficient of rolling resistance, called Crr, describes how efficiently the tire rolls under load. Lower values mean easier rolling.
Pressure And Surface Effects
Pressure changes tire shape. A soft tire may bend more and waste energy. A tire that is too hard can bounce on rough surfaces. The best pressure depends on tire width, load, road texture, and comfort needs. This calculator lets you compare settings rather than trust one fixed number.
Advanced Tire Setup
Surface quality also matters. Smooth pavement usually gives the lowest multiplier. Chip seal, gravel, wet roads, and rough paths raise the required force. Front and rear loads may differ. That is why advanced mode can blend separate front and rear Crr values.
Power And Energy
Power is force multiplied by speed. Because speed is part of the formula, rolling power rises in direct proportion to speed. If speed doubles, rolling resistance force stays similar, but rolling power roughly doubles. Aerodynamic power rises much faster, so rolling losses are only one part of cycling demand.
Electrical Planning
Energy is power multiplied by time. The calculator also converts that energy into watt-hours. This is useful for electrical planning. E-bike users can compare tire setups, estimate battery use, and see how motor efficiency changes battery draw.
Practical Use
Use the result as an engineering estimate. Real tires vary by casing, tread, temperature, tubes, sealant, rim width, and road vibration. Lab-tested Crr values are best. When they are not available, use realistic defaults and compare scenarios. The most useful answer is often the difference between two setups. Try one setup with high pressure and another with lower pressure. Check watts, watt-hours per kilometer, and estimated range. Then choose the setup that balances speed, grip, comfort, and battery life. Record common routes and repeat comparisons after changing tires, tubes, or sealant. Consistent testing makes future choices easier and more reliable overall.
FAQs
What is bike tire rolling resistance?
It is the force needed to keep a tire rolling. It comes from tire deformation, road texture, load, pressure, and tire construction.
What is a good Crr value?
Fast road tires may be near 0.003 to 0.005. Commuter and gravel tires often run higher. Use tested tire data when possible.
Does higher pressure always reduce rolling resistance?
No. Higher pressure can help on smooth roads. On rough roads, excessive pressure may increase vibration losses and reduce comfort.
Why does rider weight matter?
More rider and bike mass creates more normal force. Rolling resistance force rises with that normal force.
Can this calculator estimate e-bike battery use?
Yes. It estimates rolling-loss energy and battery draw. Total e-bike use will also include air drag, hills, starts, and drivetrain losses.
What surface multiplier should I use?
Use 1.00 for smooth pavement. Try 1.10 to 1.30 for rough pavement. Gravel may need higher values, depending on depth and texture.
Why enter front and rear tire values?
Front and rear tires may carry different loads. They may also use different pressures or tire models. Weighted Crr improves the estimate.
Is rolling power the same as total cycling power?
No. Total power also includes aerodynamic drag, climbing power, acceleration, bearing friction, and drivetrain losses.