English: An elastic wheel rolling on a rigid surface with linear velocity v and angular velocity ω experiences a braking torque due to uneven distribution of normal forces at the contact surface. The total normal force N is equal an opposite to the force of gravity F_g but is applied off-center with a finite torque. The torque is translated to a braking force by the static friction F_f on the contact surface. Small blue arrows show th schematic distribution of the combination of normal forces (normal to the surface) and static friction (along the surface) on the contact surface. This work uses some vector elements of File:Resistance_roulement_cylindre_aplati.svg by User:Cdang in a modified form.