Gears and cadence cannot predict the career span of a sprinter. Hesslich taken his first medal of Worlds at age of 18; and his last at age of 28. His closest teammate -- Huebner -- was just of a different breed. He reached the world podium first at age of 24 and last at age of 37. Huebner probably used similar gears (I estimated 50/14 in a certain event).