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Rolling resistance, sometimes called rolling friction or rolling drag, is the force resisting the motion when a body (such as a ball, tire, or wheel) rolls on a surface. It is mainly caused by non-elastic effects; that is, not all the energy needed for deformation (or movement) of the wheel, roadbed, etc., is recovered when the pressure is removed.
A bicycle wheel is a wheel, most commonly a wire wheel, designed for a bicycle. A pair is often called a wheelset, especially in the context of ready built "off the shelf" performance-oriented wheels. Bicycle wheels are typically designed to fit into the frame and fork via dropouts, and hold bicycle tires.
SAE J1269 and SAE J2452 performed on new tires. SAE J2452 is a standard defined by the Society of Automotive Engineers [1] to measure the rolling resistance of tires. [2] Where the older standard, SAE J1269, produces measurements of rolling resistance under steady-state (i.e. thermally equilibrated) operating conditions, SAE J2452 produces measurements during a transient history of speed that ...
For example, if a fat-bike tire is inflated to 0.5 bar (50 kPa; 7.3 psi) gauge pressure at room temperature 20 °C (68 °F) and then the temperature is decreased to −10 °C (14 °F) (a 9% decrease in absolute temperature), the absolute pressure of 1.5 bar (150 kPa; 22 psi) will be decreased by 9% to 1.35 bar (135 kPa; 19.6 psi), which ...
Rolling resistance can vary by a factor of 10 or more depending on type and dimensions of tire and the tire pressure. [17] Air resistance increases greatly as speed increases and is the most significant factor at speeds above 10 to 12 miles (15 to 20 km) per hour (the drag force increases in proportion to the square of the speed, thus the power ...
SAE J1269 is a standard test defined by the Society of Automotive Engineers [1] to measure the rolling resistance of tires under conditions of thermal equilibrium. [2] [3] SAE J2452 is an alternative procedure for measuring rolling resistance under conditions similar to a vehicle coastdown event, where the tire is in a roughly isothermal condition (but not thermal equilibrium).
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Rolling resistance is the main key factor in measuring the energy efficiency of a tyre and has direct influence on the fuel consumption of a vehicle. A set of tyres of the green class "A" compared to a "G" class can reduce fuel consumption by 9% [3] of a passenger car; even more for trucks.