Model dependence between the current ω and mass for log(t) = 7.3 (Georgy et al. 2013). The behaviour is shown for rotation rates at birth, ω_init, ranging from 0.1 to 0.95. The observed ω and M values for the stars with and without [N/C] data are overplotted as filled circles and open squares, respectively. For clarity, only the former are shown with error bars. The star GES 10355661–5812407 is off scale because of a spuriously large mass.