Hypernym for wheels, tracks, etc

One term used for aircraft is

undercarriage
_NOUN

1 A wheeled structure beneath an aircraft, typically retracted when not in use, which supports the aircraft on the ground.
the undercarriage collapsed on landing

and also more generally

1.1 The supporting frame under the body of a vehicle.
security guards checked the BMW's undercarriage with a large mirror

From Lexico

Wikipedia has the broader definition

Undercarriage is the part of a moving vehicle that is underneath the main body of the vehicle. The term originally applied to this part of a horse-drawn carriage, and usage has since broadened to include:

• The landing gear of an aircraft.
• The chassis of an automobile.
• The tractor treads of a tractor or tank.
• The underframe of a locomotive
• The undercarriage assembly of a train car or locomotive, known as a bogie, incorporating the train wheel sets, suspension, brakes and, in powered units, the traction motors