They tire the legs and burn the lungs, but the Tour de France's punishing climbs can't come soon enough for Lance Armstrong.

After an unnerving first week of fast racing, where crashes are a constant risk, Armstrong is looking to the hills and mountains of eastern France to start winnowing out the field of 185 riders left in the three-week race.

The six-time champion remained the overall leader after finishing a safe 53rd in the pack behind Australia's Robbie McEwen, who won Friday's seventh stage.

Saturday's eighth stage brings the hardest climb so far, the 3,736-foot Col de la Schlucht. It is not as hard as the monstrous ascents to follow in the Alps and Pyrenees, where riders who are carrying injuries, who are fatigued and out of form -- or who don't have Armstrong's climbing talents -- could fall behind.

"The race is about to start. We've made it through the first week, there have not been any major crises. In fact, I think it's been a pretty good week," Armstrong said after surviving another bunched-up finishing sprint as the Tour veered into Germany.

"Of course these stages are always scary, you have to stay out of trouble," he said. "But I'm glad to be one week down, two to go."

Armstrong avoided a crash in Friday's closing straightaway that took down two riders.

The American's lead over Discovery Channel teammate George Hincapie stayed unchanged at 55 seconds, with rival Alexandre Vinokourov of Kazakhstan still 1 minute 2 seconds back in third place. Armstrong built up his lead by riding strongly in time-trial races against the clock earlier in the week. One of those was a team event that Discovery won.

Saturday's 143.8-mile run starts in the German town of Pforzheim and leads straight into a series of four climbs.

Tour ascents are rated on a rising scale of difficulty from four upward. The hardest climbs are so difficult they're not even categorized. There are five of those on this year's Tour.

The first four hills on Saturday rate 3, or moderately hard. Riders then have about 80 miles of flat terrain before the Col de la Schlucht. Its 10.4-mile ascent rises at an average gradient of 4.4 percent and rates a 2. Then comes a downhill run to the finish in Gerardmer, back in eastern France's Vosges region.

The stage should favor all-around riders who can both climb and ride hard on flats, rather than sprinters like McEwen. The route and another six ascents that await on Sunday could provide an early gauge of the climbing form of Armstrong and his challengers heading into the Alps. Those high mountains start Tuesday after riders get a rest day on Monday.

Armstrong is confident that he will be able to head off any challenges. He even held out hope that the climbs could tempt rivals to test him. That could string out the field if Armstrong and his team ride hard in response, preventing a repeat of the massed sprints that characterized finishes in the first week.

"I feel certain that my condition is good enough to follow some attacks," he said. "In fact, some attacks would be nice so that we don't have a field sprint again."

Armstrong, 33, is trying for a seventh straight victory in cycling's showcase event before retirement. He seems to be savoring his farewell race, looking relaxed and taking more time to talk to reporters and sign autographs for fans.

"In terms of the pressure . . . nothing compared to last year," he said. "I'm a little relieved that I don't have that pressure of trying to win that sixth Tour that no one thought could be done. So this one feels different in that regard."

Australia's Robbie McEwen crosses the finish line to win the seventh stage.