Ball bearings are complex components where local deformations are the main factor on the global behavior. One problem is the relation between a contact configuration and the load level. When those components are assembled, position errors have important effects on those contact configurations. A rigid ball bearing has very small clearances that give tolerances impossible to achieve. How can the designer write geometric specifications on the assembly taking into account bearing elastic behavior?. We propose a method to identify the limits of those errors according to the ball bearing limits and the clearances. The built model has been compared with industrial references with good accuracy.