The Belmont Stakes is currently contested at 1 ½ miles, or 12 furlongs, making it the longest of the Triple Crown races and typically the longest race that Thoroughbreds who compete in the series will ever run.. The overall speed record for the Belmont Stakes is held by the one and only Secretariat (1973), who ran the race in an astonishing 2:24.00 flat, while also establishing the fraction …