On a day when the British rider was planning to save some energy for upcoming mountains, Froome still brushed aside the field and took his third stage win of this 100th Tour.
Alberto Contador, Froome's Spanish rival still trying to make a fight of this one-sided battle, gave his all in Wednesday's Alpine time trial. His face contorted in a rictus of effort as he sprinted out of the saddle to the line, while spectators whipped up a thunderclap of noise by banging their fists on the barriers.
Froome, having set off behind Contador, sped in a few moments later. He, too, rode hard but looked more comfortable with his easy-on-the-eye pedaling style, perched on his saddle, legs pumping underneath him like pistons in an ocean liner's engine room.
Contador shook his head and shrugged his shoulders when television flashed that Froome beat his time by 9 seconds. This was another opportunity lost for Contador to make victory for Froome in Paris on Sunday at least feel less inevitable.
"Froome is in impressive shape," was the understated assessment of the 2007 and '09 winner who was stripped of his 2010 victory for a failed doping test.
The last Tour champion — now ex-champion — to carry as many stage wins as Froome to Paris was Lance Armstrong. That was in 2004, when Armstrong won five stages and declared he'd be giving "no gifts" to his rivals. That is all just a bad memory now. This Tour is the first since the serial doper's name was erased last year from the race's honour roll, literally crossed out in the official history book.
Froome swears that won't happen with him. He has repeatedly said when asked at this Tour that he is riding clean — an assurance that only has limited value in the poisonous atmosphere of doubt that is a legacy of the Armstrong years and the American's confession to Oprah Winfrey this January that he cheated for all seven of his Tour wins, from 1999-2007.
"The problem today is that we are traumatized by the past," Stephane Heulot, manager of the French Sojasun team, said in an interview. "We've seen too many stories like this. We've seen too many riders swearing on the heads of their kids, their grandmothers, their mothers that they're completely clean and then — bam! — 15 years, 10 years, five years later we're told other things. Someone's word no longer means anything. We can't rely on that."
A union that represents about 600 professional riders from seven European nations supported Froome on Wednesday against what it called "unjustified allegations of doping."
"It's not fair to blame someone without evidence against him," Gianni Bugno, president of the Association of Professional Riders, said in a statement. "We demand more respect for Chris and for all the riders."
In four days, as long as he gets through the Alps, Froome will be able to sip champagne in the saddle on the final ride to the Champs-Elysees, unusually staged in the evening this year. That would make it two victories in a row for Britain and for Team Sky, after Bradley Wiggins' win last year.
With wins in the Pyrenees and on Mont Ventoux, Froome has shown excellence going uphill. It would be a big surprise if he wilted on the three days of Alpine climbs that start on Thursday with a double ascent to the ski station of L'Alpe d'Huez, with its 21 hairpins bends to the top. Done twice, that's 42 bends packed with spectators to be negotiated. It promises to be frenzied and spectacular — a dramatic crescendo for what already has been a highlight-rich Tour.
But there are questions about how comfortable Froome is speeding downhill. He has voiced concern about a hairy descent without safety barriers that the pack tackles between the first and second ascents to L'Alpe d'Huez. He appealed to race organizers to cancel the Col de Sarenne descent and make the pack ride just once to L'Alpe d'Huez if it rains on Thursday.
"Just in terms of the safety of the riders, I think that has to come first," Froome said.
That eventuality was ruled out by Jean-Francois Pescheux, the event director.
"This is the Tour de France. Rain hasn't ever stopped the Tour de France. It would have to really be a natural catastrophe that blocked the road or something like that," he told The Associated Press.
"Rain isn't the enemy of the cyclist — it's part of the sport!"
It was certainly part of Wednesday's time trial, but not as much as initially feared. While it did rain on parts of the course, the forecast storms hit only after Stage 17 finished. That was a relief because the route went up two climbs in the mountains above the man-made Serre-Poncon lake. The twisting descents could have been terribly treacherous if wetter.
Froome covered the 32 kilometres (20 miles) in 51 minutes, 33.66 seconds.
"I went into today thinking: 'OK, I'm going to give this a really good shot, but I'm not going to empty myself," Froome said. "I really expected to lose at least 30 seconds to a minute to some of the best riders."
Contador's gutsy ride bumped him up from third to second in the overall standings, although he is more than four minutes back from Froome.
"When you are second, it's easier to get to first place," Contador said hopefully. "But it's true that he is very strong."
Bauke Mollema dropped from second to fourth overall. The Dutch rider went too fast into a right-hand bend, slapped into the barriers and briefly came to a stop.
Victoria's Ryder Hesjedal finished 28th to move up to 65th in the overall classification. David Veilleux of Quebec City was 127th in the 17th stage and was 132nd overall. Svein Tuft of Langley, B.C., finished 165th Wednesday and was 176th overall.
Some riders chose road bikes for the tough course. Contador opted for a time trial bike with an aerodynamic back wheel. Froome used both — switching from an adapted road bike to a time trial bike for the final descent into the town of Chorges.
"The first bike was more adapted to climbing," Froome said. "The second bike was a little faster."
AP Sports Writer Jerome Pugmire and Associated Press Writer Jamey Keaten contributed to this report.