A lawn mower (1) is described, comprising a lift apparatus (100) which comprises at least a first arm (170) pivoted to a frame (3) by means of a third pivot (103) and passes said cutting deck (2) from a lower position to at least one position raised off the ground (99), a drive pulley (53) is rotatably mounted with the frame (3) and is linked to a motor of the lawn mower (1), and a driven pulley (52) rotatably mounted with the cutting deck (2) is linked to said drive pulley (53) by means of at least one belt (51), a distance (PD) between the drive pulley (53) and the driven pulley (52) varies its length between 0% and 3% when the cutting deck (2) passes from the lower position to any one of said at least one position raised off the ground (99). (Figure 1).
