A continuously-variable-ratio transmission with coaxial input (from 6) and output (17), capable of operating in a least two regimes, and comprising in succession a variator (2) of the toroidal-race rolling-traction type, and gearing including both a speed-reducing unit (10) and an epicyclic mixing gear unit (15) in which the components of the mixing gear unit are locked-up in at least one of the regimes, and in which the speed-reducing unit (10) effects its speed-reduction without reversal of the direction of rotation between its input (1) and output (from 26). The operating axis (5) of the variator (2) may either coincide with the coaxial input and output of the transmission (Figure 2), or be parallel to but displaced from it (Figure 3). In addition to a brake (13) and clutch (20), operable to engage first and second regimes, a further clutch (48) operable to engage a third regime is shown.