A support carriage (6) for an agricultural machine (4) that is configured to be towed behind a tractor is adjustable between a working configuration in which the agricultural machine has a working width W and a transport configuration in which the agricultural machine has a transport width T that is less than the working width W. The support carriage (6) includes a drawbar (8) and a cross-member (10) that is attached to the drawbar and is pivotable relative thereto between a working configuration and a transport configuration. A first support wheel (22) is mounted on a first support arm (20) that is pivotably attached to the cross-member (10) for rotation about a first pivot axis (28), and a second support wheel (26) is mounted on a second support arm (24) that is pivotably attached to the cross-member for rotation about a second pivot axis (34). The first support arm (20) is pivotable through an angle X between a working position and a transport position, and the second support arm (24) is pivotable through an angle Y between a working position and a transport position where Y is substantially equal to X + 180°.