An aircraft undercarriage unit adaptable for long body or short body aircraft comprising a main leg including extendable oleopneumatic shock-absorbing means which pivotally carries at its lower end a bogie beam on which are mounted forward and rearward pairs of wheels and torque links interconnecting the forward end of the bogie beam and the main leg. The torque links include locking means whereby they are adaptable to form a tie bar, effectively forming a fulcrum. By this arrangement as the loads on the undercarriage are reduced at the end of a take-off run, extension of the oleopneumatic shock absorbing means will cause the bogie beam to tilt about the locked torque links, thereby effectively lengthening the undercarriage and increasing the maximum possible rotation angle of the aircraft.