# How to Measure Rolling Resistance of Tires

Rolling resistance is the measure of how much energy it takes to keep a tire rolling. The lower the rolling resistance, the less energy required, and the faster the tire can roll. There are several factors that contribute to rolling resistance, including weight, inflation pressure, and tread design.

Measuring rolling resistance can be done in a laboratory with specialized equipment, or on the road with a GPS device.

- The first step is to determine the weight of the vehicle
- This can be done by using a standard scale or a weighbridge
- The second step is to determine the rolling resistance coefficient (RRC) of the tires
- This can be done by measuring the tire’s width, diameter, and inflation pressure, and then consulting a tire RRC chart
- Once the RRC of the tires is known, the third step is to calculate the total rolling resistance (TRR) of the vehicle
- This can be done by multiplying the RRC by the weight of the vehicle
- Finally, once TRR is known, one can compare it against other vehicles to see how efficient each one is in terms of Rolling Resistance

## Understanding Rolling Resistance!

## Rolling Resistance Coefficient Calculator

The Rolling Resistance Coefficient (RRC) is a parameter used to quantify the energy losses that occur when a wheel or other cylindrical object rolls over a surface. It is defined as the ratio of the rolling force required to maintain a given speed to the weight of the object:RRC = Rolling Force / Weight

The lower the RRC, the less energy is lost in rolling and the higher the efficiency of motion. The RRC also depends on factors such as wheel diameter, surface roughness, and inflation pressure.

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## What is Rolling Resistance in a Tire?

Rolling resistance is the force required to keep a tire rolling at a given speed. It is affected by the tires’ contact patch (the area of the tire that is in contact with the ground), its inflation pressure, and its construction. The amount of rolling resistance also varies with speed; it is generally higher at lower speeds and decreases as speed increases.

There are two main types of rolling resistance: static and dynamic. Static rolling resistance is the force required to start rolling a tire from rest. It is affected by the weight of the vehicle, gravity, and friction between the tires and the ground.

Dynamic rolling resistance is the force required to keep a tirerolling once it is already in motion. It is caused by deformation of the tire as it rolls, hysteresis losses within the rubber, and air pressure inside the tire.Tires with high rolling resistance require more power to maintain a given speed than tires with low rolling resistance.

This means that vehicles equipped with high-rolling-resistance tires will have poorer fuel economy than those equipped with low-rolling-resistance tires.

## What is Rolling Resistance Measured In?

Rolling resistance is the force that opposes the motion of a tire rolling on a road. It is caused by deformation of the tire as it rolls, and by friction between the tire and road surface. Rolling resistance is measured in terms of the force required to overcome it and is usually expressed in newtons or pounds per square inch.

The amount of rolling resistance depends on the type of tire, its inflation pressure, and the surface on which it is rolling.

## Do Tires Have a Rolling Resistance Rating?

Yes, tires have a rolling resistance rating. This is a measure of how much energy is required to keep the tire rolling at a given speed. The higher the rating, the more energy required, and the lower the fuel economy.

## How Do You Calculate Rolling Friction?

Rolling friction is a type of kinetic friction that occurs when an object rolls along a surface. It is usually caused by the deformation of the surface as the object presses down on it. The amount of rolling friction depends on the material of the object and the surface, as well as the speed at which it is moving.

To calculate rolling friction, you need to know the coefficient of rolling friction (μ) between the two materials in contact. This can be found experimentally or from data tables. Once you have μ, you then need to determine the normal force (N) exerted on the object by the surface.

This is simply equal to the weight of the object times gravity (9.81 m/s2). With these two values, you can then calculate rolling friction using this equation:FR = μ x N

So, for example, let’s say you want to calculate rolling friction for a car with a mass of 1,000 kg (1 tonne) travelling at 5 m/s on a road with a μ value of 0.01. The calculation would be:FR = 0.01 x 1,000 kg x 9.81 m/s2

## Conclusion

The rolling resistance of a tire is the measure of the force required to keep a tire moving at a constant speed. It is affected by the weight of the vehicle, the surface area of the contact patch, and the inflation pressure of the tire. The higher the rolling resistance, the more fuel your vehicle will use.

You can test the rolling resistance of your tires with a simple experiment.