 In 1968, he would move up to compete in the 250cc Grand Prix world championship.Although the single cylinder Ossa had 20 horsepower (15 kW) less than the powerful V4 Yamahas of Phil Read and Bill Ivy, the Ossa was 45 pounds (20 kg) lighter and its monocoque frame was much stiffer, giving it superior agility.Herrero was able to take advantage of the Ossa's light weight and superior handling characteristics to remain competitive, especially on tighter race tracks.