Who rode rheingold when it was 2nd to Roberto in 1972 derby?

Rheingold was ridden by jockey Joe Mercer when he finished second to Roberto in the 1972 Epsom Derby. Mercer was a prominent jockey known for his skill and success in major races during that era. Rheingold's performance in the Derby was notable, as he was a strong competitor in a field that included the eventual winner, Roberto.