"[T]he bicycle had a decided influence on the... automobile. The bicycle introduced thousands... to individual mechanical transportation, and proved the value of many materials and parts that were subsequently taken over by the automobile designers. Ball bearings found one of their earliest uses in bicycles of 1880 or earlier. The differential unit was employed in tricycles, and various forms of freewheeling and gear-shifting devices were in use. Steel tubing, developed largely for cycle frame construction, was adopted by some early automobile builders. Pneumatic tires for cycles were patented... in the United States... 1890, by John Boyd Dunlop... of Belfast, Ireland, and were... in use on bicycles prior to that..."