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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.
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 ...
The rolling resistance coefficient (RRC) indicates the amount of force required to overcome the hysteresis of the material as the tire rolls. Tire pressure, vehicle weight and velocity all play a role in how much force is lost to rolling resistance. The basic model equation for SAE J2452 is: Rolling Resistance (N / lbs) = (+ +) where: is the ...
Your tires actually play a surprising role in how fast you ride, and what you think you know about rolling resistance is probably wrong.
This template displays the symbol for coefficient of rolling resistance with an optional link to Rolling resistance (link=yes) and an optional value. If long=yes then the phrase 'rolling resistance of' is added to the front to make it easier to read as part of a full sentence.
chemistry (Proportion of "active" molecules or atoms) Arrhenius number = Svante Arrhenius: chemistry (ratio of activation energy to thermal energy) [1] Atomic weight: M: chemistry (mass of one atom divided by the atomic mass constant, 1 Da) Bodenstein number: Bo or Bd
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).
where F is the rolling resistance force (shown in figure 1), r is the wheel radius, b is the rolling resistance coefficient or coefficient of rolling friction with dimension of length, and N is the normal force (equal to W, not R, as shown in figure 1). Equating the above two equations, and solving for b, gives b = Crr·r.