"A wheelset is the wheel–axle assembly of a railroad car. The frame assembly beneath each end of a car, railcar or locomotive that holds the wheelsets ...
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is called the bogie (or truck in North America). Most North American freight cars have two bogies with two or three wheelsets, depending on the type of car; short freight cars generally have no bogies but instead have two wheelsets." - (en.wikipedia.org 18.02.2020)