Post-main sequence evolutionary tracks in the Taylor-Spruit scheme with v_ini =  300 km s⁻¹. Left panel: HRD from the (TAMS with squares), through the helium-TAMS (diamonds), until carbon-TAMS (blue stars). The colours denote different initial masses. On the right-hand side of this panel, the TAMS masses are shown in solar units and the ZAMS masses are indicated in brackets. Corresponding to these cases, the masses at the C-TAMS are also shown in solar units on the left-hand side. Middle and right panels: post-main sequence evolution of core and surface helium, carbon, and oxygen mass fractions for the initially 315 M_⊙ model.