Although his cycling career was brief, Alain Vasseur did enjoy some moderate success as both an amateur and professional rider. In 1968 Vasseur won the Paris-Roubaix under-23 race, along with two stages of the Tour de l’Avenir. These performances earned him a place on the Olympic team for the Games in Mexico City, where he placed 20th in the road race. One year later he turned professional, winning the Four Days of Dunkirk road race and finishing tenth in the Paris–Nice stage race. Vasseur had his biggest career win in 1970 when he won the eighth stage of the Tour de France, beating Walter Godefroot by more than one minute. He rode the Tour again in 1971 and 1974, but did not replicate his early glory and retired in the mid-1970s. His son Cédric was also a professional cyclist who won stages of the Tour de France in 1997 and 2007.
France