 The majority of his years as a professional were under the sponsorship of Palmans and its various co-sponsors.Born in Oudenaarde, Belgium, De Clercq is a three-time world cyclo-cross champion capturing the 1998, 1999 and 2002 UCI Cyclo-cross World Championships.In addition, De Clercq won the 2001 and 2002 Belgian National Cyclo-cross Championships.