Method and apparatus for detecting a tire deformation of a bicycle

The method and the computing unit detect a segment of the lateral outer surface of the tire casing to a first (210) and one of the first instant in time following the second time point (230), said segment adjoins the contact region of the tire casing to the ground. Subsequently, the outer surface of segments detected compared (250) and a tire deformation can be determined in dependence on the detected at the two different times outer surface segments (270). The detected tire deflection is additionally used in a method and a process executing arithmetic unit for controlling (330) the braking behavior.