A clutch for vehicles comprises a driving member (10) and a driven member (22) coaxial to the driving member, with a pack of clutch plates between them which are alternatively connected to the driving member and to the driven member, a pressure member (38) engaged by elastic means (44) to push the clutch plates against a ledge (10b) of the driven member, a floating member (20) that is axially translatable between the driven member (10) and the pressure member (38), and driving means (22, 24, 26) on said driving member and floating member which are in mutual, rotary and shifting engagement to axially push the floating member (20) against the pressure member in contrast to said elastic means. The driving means comprises rollers (22) each pivotally supported by the driving member (10) about a substantially radial axis to engage respective inclines (26s) that are frontally made on the floating member.