During World War II, José Beyaert served in the French resistance, presaging a later life behind the lines. Prior to the 1948 Olympics, Beyaert had minimal credentials as a cyclist outside of France, winning the minor Paris-Briare race in 1947, placing third in the 1947 Paris-London stage race, and finishing 11th that year at the World Amateur Championships. After the 1948 Olympics, he turned professional and had a few minor wins in 1950 - the Grand Prix d'Isbergues and Paris-Boulogne sur Mer. He rode in both the 1950 and 1951 Tour de France, placing 47th in 1950 and abandoning in 1951, and rode several of the one-day classics in those years as well.
Beyaert then settled in Colombia where he won the 1952 Tour of Colombia, but he rode for only a few more years. He spent most of his life in Colombia, returning to France to live only in 2000. His activities in Colombia are poorly documented, but a biography Olympic Gangster, by Matt Rendell, tells much of what is known. While there he worked at various times as a cycling coach, an emerald trader, a logger in Brazíl, where he had a lover and several children, and as a businessman, as he and his wife, Louisette, ran a café in Bogota. There are many holes in the story that cannot be fully filled, but Beyaert probably worked as a drug smuggler, trafficking in cocaine and heroin. He made many trips throughout South and Central America, and back to France, and his associates were known to be in this trade, notably several of those whose story was later told in the book and movie, “The French Connection,” about the French drug trade. The book also details suspicions about possible murders Beyaert committed during his work, but so much of his life was mired in mystery, that it is difficult to be certain of this. Later in life, Beyaert helped train and coach some of the first Colombian teams that rode in the Tour de France, and served as a cycling commentator for Colombian television and radio.