The invention concerns a wheeled vehicle (10) which is able to regulate its lateral tilt. In a preferred aspect the vehicle (10) comprises a seat (28) for supporting a rider, and a chassis (18) which carries the seat. A steerable wheel (12) is carried by the chassis and is operably coupled to a steering arrangement (30, 34) for turning the steerable wheel (12) to effect steering of the vehicle (10). A left wheel-bearing arm (66) carries a left wheel (14) and is pivotally coupled to the chassis (18), so that pivotal movement of the left wheel-bearing arm (66) provides up and down movement of the left wheel (12) relative to the chassis (18). A right wheel-bearing arm (68) carries a right wheel (16) and is pivotally coupled to the chassis (18) to be movable independently of the left wheel-bearing arm (66), so that pivotal movement of the right wheel-bearing arm (68) provides up and down movement of the right wheel (16) relative to the chassis (18). A left control line (76) is led from a left tether (79) on the left wheel-bearing arm (66) to an actuator (84) carried by the chassis (18), so that upward movement of the left wheel (14) relative to the chassis is restrained by the control line (18). A right control line (82) is led from a right tether (78) on the right wheel-bearing arm (68) to the actuator (84), so that upward movement of the right wheel (16) relative to the chassis (18) is restrained by the right control line (82). The actuator (84) is operable in a first direction to pay out the left control line (76) whilst drawing in the right control line (82), permitting the left wheel (14) to move up relative to the chassis (18) and causing the right wheel (16) to move down relative to the chassis (18), thereby causing the vehicle (10) to tilt toward the left. The actuator (84) is operable in a second direction to pay out the right control line (82) whilst drawing in the left control line (76), permitting the right wheel (16) to move up relative to the chassis (18) and causing the left wheel (14) to move down relative to the chassis (18), thereby causing the vehicle (10) to tilt toward the right.