Towing system comprising: - a bar having a longitudinal axis (4.1), - a first attachment device arranged at a first end of the bar, the first attachment device being able to attach the towing system to a towing vehicle, - a second attachment device arranged at a second end of the bar, the second attachment device being able to attach the towing system to a travelling machine to be towed, wherein the second attachment device comprises a fork able to hold at least one wheel of the travelling machine, the fork having: - two longitudinal members (6.1, 6.2) between which at least one wheel of the travelling machine is able to be received, each longitudinal member (6.1, 6.2) having a longitudinal axis (6.3, 6.4) substantially parallel to the longitudinal axis (4.1) of the bar, - a separation device able to modify the spacing between the two longitudinal members (6.1, 6.2), - a holding device (9.1, 9.2, 8.1, 8.2) able to hold the wheel between the two longitudinal members (6.1, 6.2). characterized in that the separation device comprises: -two sliding arms (10.1, 10.2), each sliding arm (10.1, 10.2) having: ∘ a longitudinal axis (10.3, 10.4) forming an angle (α) with the longitudinal axis (4.1) of the bar, ∘ a first part (11.1, 11.2), one end of which is fixed to one end of one longitudinal member (6.1, 6.2), and ∘ a second part (12.1, 12.2), one end of which is fixed to the second end of the bar, the second part (12.1, 12.2) being able to slide in the first part (11.1, 11.2) along the longitudinal axis (10.3, 10.4) of the sliding arm (10.1, 10.2), - an actuation device configured so as to cause the simultaneous sliding of the sliding arms (10.1, 10.2). - a bar having a longitudinal axis (4.1), - a first attachment device arranged at a first end of the bar, the first attachment device being able to attach the towing system to a towing vehicle, - a second attachment device arranged at a second end of the bar, the second attachment device being able to attach the towing system to a travelling machine to be towed, - two longitudinal members (6.1, 6.2) between which at least one wheel of the travelling machine is able to be received, each longitudinal member (6.1, 6.2) having a longitudinal axis (6.3, 6.4) substantially parallel to the longitudinal axis (4.1) of the bar, - a separation device able to modify the spacing between the two longitudinal members (6.1, 6.2), - a holding device (9.1, 9.2, 8.1, 8.2) able to hold the wheel between the two longitudinal members (6.1, 6.2). -two sliding arms (10.1, 10.2), each sliding arm (10.1, 10.2) having: ∘ a longitudinal axis (10.3, 10.4) forming an angle (α) with the longitudinal axis (4.1) of the bar, ∘ a first part (11.1, 11.2), one end of which is fixed to one end of one longitudinal member (6.1, 6.2), and ∘ a second part (12.1, 12.2), one end of which is fixed to the second end of the bar, the second part (12.1, 12.2) being able to slide in the first part (11.1, 11.2) along the longitudinal axis (10.3, 10.4) of the sliding arm (10.1, 10.2), ∘ a longitudinal axis (10.3, 10.4) forming an angle (α) with the longitudinal axis (4.1) of the bar, ∘ a first part (11.1, 11.2), one end of which is fixed to one end of one longitudinal member (6.1, 6.2), and ∘ a second part (12.1, 12.2), one end of which is fixed to the second end of the bar, the second part (12.1, 12.2) being able to slide in the first part (11.1, 11.2) along the longitudinal axis (10.3, 10.4) of the sliding arm (10.1, 10.2), - an actuation device configured so as to cause the simultaneous sliding of the sliding arms (10.1, 10.2).