Surface rotational velocity as function of time for models with different initial masses and rotational velocities as indicated by the legend (units are [M_⊙]−[km s^-1]). The time is normalised to the main-sequence lifetime of the stars and the rotational velocity is normalised to the ZAMS value (see Sect. 3.1). The track of the 294 M_⊙−450 km s^-1 model which evolves chemically homogeneously is plotted with a dotted line for comparison.