This is not the same stool from the documented second version of Marcel Duchamp’s Bicycle Wheel, so maybe this is the original 1913 version, and maybe when Duchamp was explaining the concept of a Readymade as a Christmas tree on a stool to Katherine Dreier in New York, someone just misheard it as bicycle wheel, and Duchamp just rolled with it. And then he gave her this photo and told her never to tell anyone.