The 24-year-old German, riding in his first Tour, captured the leader's yellow jersey as cycling's premiere event entered three days in the Alps with today's seventh stage.

Gerdemann's T-Mobile team has been scarred more than most over doping revelations, and has responded in the past year by enacting some of the toughest anti-doping policies in the sport.

Gerdemann clocked 4 hours, 53 minutes, 13 seconds. Inigo Landaluze of Spain was second, 46 seconds back. David de la Fuente of Spain was third, 1:39 back.

Overall, Gerdemann leads Landaluze by 1:24 and De La Fuente by 2:45, and will don the yellow jersey tomorrow for the second of three punishing Alpine rides. The 102.5-mile stage from Le Grand Bornand to Tignes features six climbs — including an uphill finish.

Gerdemann is the second rider to don the yellow jersey this year, after Swiss rider Fabian Cancellara held it for the first eight days. Cancellara finished 22:27 behind today.

In post-race news conferences today, Gerdemann used the word "clean" at least six times. He spoke about blood tests he had undergone. He decried the harm done by doping in the sport, and said he understood fans have doubts.

"It's really hard for young riders to take the responsibility now," Gerdemann said. "But the sport gave a lot to me in the past — and now I think it's the right moment to give something back."

It was a fresh voice at an event where many riders and staffers refuse to discuss doping or get short-tempered even when the word comes up — saying they want to focus only on "the sport."

T-Mobile has sought publicly to stake out the high ground.

"I don't want to say that just T-Mobile is a clean team," Gerdemann said. "I think many, many teams realize that the old-school way is not the way anymore — but for sure, we have to show the way more and more."

The team's former star, 1997 Tour winner Jan Ullrich, was disqualified from racing on the eve of the start of last year's Tour after his name turned up in a Spanish blood-doping investigation. In recent months, several former riders from the Telekom team — as T-Mobile was formerly called — admitted to doping in the 1990s.

The team and Tour organizers are eager to hoist up young riders like Gerdemann as potential harbingers of a new era.

"It's the fresh air we were hoping for, with a team that has taken exemplary measures," Tour director Christian Prudhomme said.

The ride into the Alps has been expected to weed out the potential favorites in the three-week race, but two time trials and the Pyrenees also lurk down the road.

Gerdemann won by speeding out from a group of breakaway riders during the 123-mile ride from Bourg-en-Bresse to Le Grand-Bornand, featuring a winding ascent up La Colombiere Pass, the first category 1 climb this year.

After last year's climb of the 10-mile La Colombiere ascent, 2006 Tour winner Floyd Landis tested positive for synthetic testosterone after the 17th stage. An arbitration panel is deciding whether Landis should be allowed to keep his title.

Two pre-race favorites — Astana teammates Alexandre Vinokourov of Kazakhstan and Germany's Andreas Kloeden — made it through another day nursing injuries from crashes during a frenzied stage Thursday. Kloeden has a hairline fracture in his tailbone and Vinokourov has stitches in both knees.

Other potential contenders for the 2007 Tour title — including American Levi Leipheimer, Australia's Cadel Evans, Alejandro Valverde and Oscar Pereiro of Spain, and Russians Vladimir Karpets and Denis Menchov — didn't seek to exploit the Astana riders' troubles. All favorites finished in a bunch of 35 riders that was 3:38 back of Gerdemann.

The race is also picking up speed.

Despite the climbs, Gerdemann averaged 25.1 miles per hour, up from an average of 24.8 mph by the stage winners in the first six stages across flat terrain in northern France, Belgium and southeast Britain. London hosted the Tour start for the first time.

Fallout from doping in cycling continues to hover over the race this year. Tour officials confirmed today that Erik Zabel, a German rider with the Milram team, will no longer be considered the winner of the green jersey, awarded to the race's best sprinter, in 1996.

Zabel, who won the green jersey a record six times, said in May he used the banned performance enhancer EPO for one week as a Telekom rider in the Tour that year — but never again.