axletree vs crossbar

axletree

noun
  • A bar or beam of wood or iron, connecting the opposite wheels of a carriage, on the ends of which the wheels revolve. 

  • A stimulus or driving force. 

  • A spindle or axle of a wheel. 

crossbar

noun
  • Any transverse bar or piece, such as a bar across a door, or the iron bar or stock which passes through the shank of an anchor. 

  • The top of the goal structure. 

  • The top tube of a bicycle frame. 

verb
  • To mark with a pattern of transverse bars. 

How often have the words axletree and crossbar occurred in a corpus of books? (source: Google Ngram Viewer )