at the 2005 tour de france, he started out comparatively weakly on stage 10, the first mountain stage of the race, where he trailed the front group by a minute. but for the rest of the race, ivan basso was once again the only rider to keep up with the race leader lance armstrong in the mountains, and on occasion he tried to pressure the eventual winner by going on the attack. basso was still weaker in the time trials, although he had improved significantly when compared to 2004. he lost a collective 3:47 over two time trial stages, as basso placed second overall in the tour, 4:40 behind lance armstrong. during the 2005 tour de france, basso signed a new three-year contract with team csc.