Bradley Wiggins may have a firm grip on the yellow jersey after the first week of the 2012 Tour de France, but defending champion Cadel Evans isn't so sure the British rider can keep up his relentless pace for the entire race without faltering.

Evans is nearly 2 minutes behind his main rival after losing time in Monday's long time trial, which Wiggins won to cap a flawless first week of racing.

But Evans said Wiggins is still relatively untested in the major races and is hoping his own experience will make the difference over the next two weeks, before the race ends in Paris on July 22.

"If I was going to convince myself now he was unbeatable and unstoppable, well I might as well decide on second," Evans told Roadcycling.com during the Tour's first rest day. "He doesn't have much of a history over three weeks compared to someone like me."

Before triumphing on the Champs Elysees last year, the 35-year-old Evans had twice finished second overall. Wiggins, a three-time Olympic champion on the track, achieved his best result on the Tour three years ago when he finished fourth. The lanky British rider ended a disappointing 24th in 2010 and crashed out of the race with a broken collarbone last year.

"Most of the other riders in the first 10, we've seen them more at their limits, have more three-week Tours to judge them by," Evans said.

Wiggins acknowledged that he lacks Evans' experience.

"This is my fourth Tour de France going for G.C. (general classification)," Wiggins said on the eve of the first big mountain stage of the race. "Each year's got a bit better. We've worked on those areas where I was a bit weak. But I'm only human. Who knows what lies in store next week?"

Wiggins and his Sky Team have dominated the 2012 Tour de France so far. The 32-year-old Londoner outclassed all his rivals in the time trial and the British team set such a fast tempo during the first two medium mountain stages that no other Tour contender dared to attack.

Team Sky has another contender in Christopher Froome, the revelation of this Tour so far. The Kenyan-born rider is proving himself as one of the best climbers in the world and stands third overall, 2:07 behind his teammate.

"Up to now it's been a dream," Wiggins said. "I don't see any reason why it should fall apart at this stage, but it's sport, that's what sport is all about."

Evans, who placed only sixth in Monday's 41.5-kilometer race against the clock to Besancon, will have to attack in the mountains to stand a chance of unsettling Wiggins.

"We're really at the midway point of the race now, and in the second half is where I come into my best," Evans told Roadcycling.com and added "From here, we'll keep going, we'll keep on working at it and we'll keep on racing till the end."

Evans, a former mountain biking specialist, expects the race to take a different shape in the second week, with more contenders reaching their peak in the mountains and more stages finishing downhill.

"There will be a lot of reshaping of the general classification," Evans explained and continued "In the past, I was driven by questions over my own abilities. Now I know I can win the Tour. I want to be able to bring back another yellow jersey when I arrive back home in Australia this year."

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