The transmission (1) comprises a housing (2), a first motor (41), a second motor (42), a first and a second input shaft (51, 52), respectively able to be driven in rotation, one (51) by the first motor (41), the other (52) by the second motor (42), two clutch mechanisms (71, 72) and two reduction gears (91, 92), wherein the output shaft (31, 32) is formed by two output shaft sections (31, 32) interconnected such that they rotate freely, the clutch mechanisms (71, 72) are each equipped with a clutch control member operable by a user for allowing the transmission, in the engaged state of the first clutch mechanism (71), of the rotational movement of the first input shaft (51) to the first output shaft section (31), and the transmission, in the engaged state of the second clutch mechanism (72), of the rotational movement of the second input shaft (52) to the second output shaft section (32), and the reduction gears (91, 92) are at least partially received inside the housing (2).