Drug-tainted British sprinter Dwain Chambers bowed out of the 100m on Sunday but said his appearance at the London Olympics was \"worth every moment\" of his fight to reach the Games. Chambers, running in the lane next to defending champion Usain Bolt in the second semi-final of the blue riband event, finished fourth in 10.05sec, not good enough to secure him a spot in Sunday evening\'s final. The 34-year-old Londoner finished fourth in the 100m at Sydney 2000 but he was caught using the designer steroid THG in 2003 and banned for two years. Chambers was only cleared to compete in London in April after overturning a British Olympic Association bylaw that imposed a lifetime Games ban on drugs cheats, although he has been eligible to compete at world championships. \"I wanted to do well and get into the final but I\'m happy to be here, I really am,\" Chambers, who won 100m bronze at the 1999 world championships, told the BBC. \"I am gutted that I didn\'t make the final but you can you can\'t have it all.\" He said the fight through the courts and his efforts on the training track had been worth it. \"It was worth every moment of it, to feel that roar and be in this atmosphere again,\" he added. \"Money can\'t buy that and I\'m glad I fought this hard to get to this position.\"