Lance Armstrong will buck Tour de France tradition by declining to wear the race leader's yellow jersey when cycling's biggest event, celebrating its centenary, begins Saturday in Paris.

Armstrong surprised fans last year by turning up for the prologue, a short-distance race against the clock that establishes the standings before the first stage proper, in his regular U.S. Postal Service blue.

Some speculated he had forgotten the "maillot jaune."

Organizers said while his stance was "unusual," it broke no rules.

"I started the 2001 race in the yellow jersey and it just didn't feel right to me," Armstrong said. "For me, it's something you should earn."

"It's a convention that the defending champion sets out with the yellow jersey," said Tour spokesman Philippe Sudres. "But there's nothing obligatory about it."