The physical parameters affecting the force required to pull a cord from the coid-rubber specimen used in a new tire cord adhesion test (TCAT) were investigated using a variety of rubber compounds and tire cords. The cord pull-out force was proportional to the square roots of cord perimeter, specimen cross-sectional area, and Young's modulus of the rubber, as anticipated from theoretical considerations. The constant of proportionality involved the square root of the energy of adhesion. The value of the energy of adhesion calculated from the proportionality constant was confirmed by an independent peel test.