The mower has spur gears (15, 18, 18', 22, 44) attached to two external mower disks as a part of a drive train, where one of the spur gears functions as a reversal gear. A main drive pinion (21) stays in engagement and drive connection with one of the spur gears. The main drive pinion is provided upstream to the spur gears along a driving- and working direction (F). A rotational axle (45) of the main drive pinion rests in a region of an axle base (33) between other rotational axles (47, 48) of the spur gears, where the axle base run transverse to the driving- and working direction. The drive train is formed as a gear transmission.