Surface velocities υsini as a function of the effective temperature for the sample of red giants observed by Carlberg et al. (2011). The red dots correspond to stars with υsini larger than 8 km s^-1. The lines indicate the evolutionary tracks for 2.5 M_⊙ stellar models for different initial rotations (from bottom to top, the time-averaged velocities during the MS phases are ~20, 100, and 280 km s^-1). The upper dotted line shows the critical velocity.