PRA LOUP, France (AP) — The speedometer clocked between 50 and 60 kilometers per hour (30-37 mph) as the pine trees whipped by, and the riders leaned left to right and back again to negotiate the snaking, bumpy descent.

Winning the Tour de France isn’t only about having the ability to get uphill fast. You’ve got to have nerves of steel going downhill too.

Chris Froome proved Wednesday that he’s got both.

The 30-year-old Briton retained the leader’s yellow jersey as the Tour sped toward its crescendo in the Alps.

The 17th stage included a harrowing 16-kilometer (10-mile) descent that dealt perhaps the final blow to Alberto Contador’s distant hope of a third Tour victory and doused the ambitions of promising French rider Thibaut Pinot for a stage win. They both lost time after hitting the asphalt on the way down from the treacherous Allos Pass.

Germany’s Simon Geschke won the stage by surging out of a breakaway bunch and keeping at bay Andrew Talansky of the U.S., who was second, by 32 seconds at the end of the 161-kilometer (100-mile) ride from Digne-Les-Bains to Pra Loup ski resort.

Fellow American Tejay van Garderen, who was third overall as the stage began, pulled out of the race with a headache and a lack of energy after fighting a respiratory infection for several days.

“It almost feels like I just want to disappear right now,” said a despondent Van Garderen. “It was hard to look my teammates in the eyes (and) it was hard to call my wife and explain to her what was going on.”

Froome, meanwhile, emerged unscathed in the first of four punishing days in the Alps, staving off multiple attacks from his top rivals. He showed great bike-handling skill on the Allos descent, where he whizzed in single-file with three of them, each kicking out knees on the twisting, narrow bends.

Geschke was first down the slope, having ridden off ahead with 50 kilometers (30 miles) still to go. Pinot hit the deck when his wheels slipped from under him on a left-hand bend.

“It was really challenging,” said Geschke, whose stage victory was the fifth by a German on this Tour, and ideal for an event that is back on public TV in Germany after a hiatus of several years because of doping scandals that tarnished the sport’s image.

“The best day of my life as a rider,” he said of his win.

Contador hit a hole and crashed in the downhill section, tearing his shorts. The 2007 and 2009 champion was forced to swap bikes with teammate Peter Sagan, and rode in more than two minutes after Froome.

“My wheel slipped and I fell. We tried to fix my bike but it wasn’t working and I took Peter’s bike,” Contador said. “I tried to descend as well as I could, but at the bottom of the climb I had to change back to one of my own bikes to minimize the losses.”

While the Spaniard stays in fifth place, the Tinkoff-Saxo leader who was hoping to add the Tour to his Giro d’Italia win in May is now a substantial 6 minutes and 40 seconds behind the Team Sky rider overall — and all but out of contention.

Froome and Nairo Quintana sprinted together for the line, with the Colombian just beating the Briton this time. Quintana remains second overall — still 3:10 behind Froome — but was very active over the day’s five climbs, testing Froome with bursts of speed that the 2013 Tour winner was forced to match.

With time running out for podium contenders to claw back a few minutes, Froome is expecting more attacks in the next three days of progressively harder Alpine climbing before the largely ceremonial ride on the Champs-Elysees in Paris on Sunday.

“My rivals are going to take bigger risks,” Froome said. “We are seeing an all-or-nothing approach.”

The descent wasn’t unknown to Froome. He’d previously raced and trained on it and that inside knowledge helped him negotiate the bends.

“I have never felt that descending has really been a weakness for me. I have always been quite comfortable on the descents,” he said.

Alejandro Valverde of Spain, Quintana’s Movistar teammate who has been riding strongly, rose from fourth to third overall, 4:09 behind Froome. Froome’s Sky teammate Geraint Thomas climbed from sixth to fourth, vaulting over Contador, and is 6:34 behind his team leader.

Riding solo for over an hour from such a long way out, up the two final climbs and alone down the descent was risky. But Geschke said he knew that other riders in his group were stronger climbers, so he decided to shake them off as early as he could.

“I took the only chance I had,” he said. “I thought, ‘OK. If it doesn’t work out, it doesn’t work out.’”

“It’s incredible it worked out,” he added.