In 1998, with the support of his former Australian Institute of Sport Sports Director, German born Heiko Salzwedel, he moved on to the big French team GAN (now Crédit Agricole) where he spent the next five years amassing more than 20 major wins, among them a day in the maillot jaune in the 2000 Tour de France, and a stage win in the 2001 Tour de France. Furthermore, Voigt played a part in Jan Ullrich's 2000 Olympic Games win for the German national team.

In 2004 Voigt moved to Danish Team CSC, where he would meet up with former Crédit Agricole teammate Bobby Julich. Together they form a strong pair, both being great tempo specialists, and they have dominated the 2004 and 2005 editions of the LuK Challenge race, a two-man time trial, together.

Jens Voigt rode the 2004 Tour de France for Team CSC captain Ivan Basso, throughout the 20 stages of the race, Jens Voigt and team mate Jakob Piil was more often than not seen in breakaways, 'covering the break' for team CSC. On the 15th stage, Voigt was in yet another break, as Jan Ullrich attacked up the mountain of Col de l'Echarasson, gapping both race leader Lance Armstrong as well as then 2nd placed Ivan Basso. With Armstrong's team seemingly unable to pull Ullrich back in, Jens Voigt was ordered back from his break-away to help Ivan Basso defend his podium placement. Voigt saw Ullrich drive past him as he waited for his captain, before he single-handedly closed the gap to Ullrich. At the next day, the riders were to ride an individual time trial up the Alpe d'Huez mountain with 900,000 spectators at the roadside. Voigt was heckled by German fans on his way up the mountain, calling him Judas for his effort to ruin fellow German Ullrich's chances. Jens Voigt reacted strongly against the treatment by criticising German TV-channel ARD for starting a witch-hunt against him, and he pleaded that his salary was being paid by Team CSC, not Germany.

At the start of the 2005 season, Jens Voigt took the victory in the stage race of Tour Méditerranéen, ahead of team mates Fränk Schleck placed 2nd and Nicki Sørensen in 4th place. Jens Voigt won the very first UCI ProTour event, as he clinched the prologue time trial of the 2005 Paris-Nice, a race Bobby Julich won overall. Voigt nearly won the 2005 edition of the classic Liège-Bastogne-Liège when he was beaten at the finish line by Alexandre Vinokourov, Jens Voigt having been on a breakaway for almost the entire race.

After a strong placing in the stage 1 time trial of the 2005 Tour de France, Jens Voigt was only trailing race leader Lance Armstrong by 1 minute, and in the following stages Voigt tried hard to take the overall lead. He subsequently took part in many attacks, and at the 9th stage, the stage before the first resting day, Voigt finally got in a break-away that lasted to the finishing line and finished third, 3 minutes ahead of Armstrong. Jens Voigt's time in the maillot jaune would be short lived however, as he fell to 168th place at stage 10 after suffering from a fever, and he was eliminated from the race for failing to finish stage 11 within the required time limit. Following his consistent riding, Jens Voigt ended the 2005 season as 29th ranked rider on the UCI ProTour individual rankings.

For the 2006 season, Voigt started out comparatively slower than in 2005 in order to save his energy for helping Ivan Basso in attempting to win both the 2006 Giro d'Italia and 2006 Tour de France races.^[5] His only result of note until the Giro started in May, was Voigt's traditional attack on the fifth stage of the ProTour race Vuelta al País Vasco, but he had to settle for second place behind stage winner Thomas Voeckler.

For the Giro d'Italia, Voigt rode in support of Basso. Following Team CSC's team time trial win on stage 5, Voigt found himself in second place, only trailing race leader Serhiy Honchar by six seconds. During the first mountain stages of the Giro, Voigt helped Basso take the overall lead of the race, while he slid down the leader board and eventually finished as the 37th ranked rider. On the mountainous stage 19 of the Giro, both Voigt and Julich were in a 20-man breakaway, but as Team CSC was leading the peloton in order to defend Basso's first place, Voigt and Julich did not work in the breakaway. Up the last climb of the stage, Voigt was alone with Spanish rider Juan Manuel Gárate, but as Voigt did not think he had done enough work on the stage to deserve the victory, he let Garate take the stage win.^[6] Voigt finally got his first win of the season in the Ster Elektrotoer race in June. Here he won stage 4 and helped teammate Kurt Asle Arvesen to the overall win, just two weeks before the start of the Tour de France.

In the days before the Tour, Ivan Basso was suspended by Team CSC after his name had been brought up in the Operación Puerto doping investigation. This meant that Carlos Sastre would become new team captain. Voigt took the role of early attacker, in order to lessen the workload for the team, and he formed or joined a number of unsuccessful breakaways on several stages. On stage 13 from Béziers to Montélimar, the longest stage of the 2006 Tour of 231 kilometers, Voigt got in a five-man breakaway which finished 29 minutes and 58 seconds ahead of the main bunch of riders. At the finish line, Voigt outsprinted Óscar Pereiro in order to take his second Tour de France stage win. On Stage 15, Voigt again helped his teammates, this time it was up-coming climber Fränk Schleck from Luxembourg, by pulling hard in the breakaway with teammate David Zabriskie of the USA, which eventually gave Schleck the win. Voigt finished the 2006 Tour in 53rd place, while helping Sastre finish 4th overall.
 

The above article is taken from wikipedia's article on Jens Voigt.