Hamilton, who admits he's not Armstrong's "biggest fan"

A former teammate of once acclaimed, now embattled former cyclist Lance  Armstrongsaid Friday that there was no question why U.S. Postal Service team members doped during big races.

"It was done by the team, but it was done for the Tour de France so I could be a good teammate for Lance Armstrong," Tyler Hamilton told CNN on Friday. "He wanted you to be riding your best in the biggest races."

Hamilton, who admits he's not Armstrong's "biggest fan," is one of 26 witnesses who testified to the U.S. Anti-Doping Agency as part of its investigation into doping by Armstrong and other riders on the team.