Individual contributions of the most important rotational instabilities to the total angular momentum transport coefficient in the j_a = 5 × 10¹⁷ cm²s^-1 (v_rot ≃ 100 kms^-1) case at four instances: panel a: shortly after mass transfer ends (“2”); panel b: near return to equilibrium (“3”); panel c: main sequence (between “3” and “4”); panel d: main sequence turn-off (“4”). Initially, large Ω-gradients favour the shear and GSF instabilities. Later on, when the Ω-gradients are erased, the overall transport is dominated by the Eddington-Sweet circulation. The lines show the angular velocity (dash-dotted) and the carbon abundance (dashed) profiles at the corresponding times.