Yellow jersey Chris Froome has won his third stage of the Tour de France maintaining a comfortable lead over rival Alberto Contador ahead of the Alps.
Froome finished today's 32km mountain time-trial in 51 minutes and 33 seconds besting Contador (Saxo-Tinkoff) who had not long before set a new benchmark of 51:42.48.
The course and inclement weather added another dimension to today's racing in which some riders, including Froome, switched from a road to time-trial bike on the course.
Froome (Sky) swapped bikes before the second time check, around the midway point, unlike his Contador who jumped from third to second overall after his effort today.
"That very well could have been a difference," Froome said of his equipment decision.
"For me personally, when I rode the route this morning I thought I needed the bigger gearing coming into the final."
Froome has a comfortable advantage over Contador and the remainder of the competition ahead of tomorrow's double ascent of Alpe d'Huez.
"I went into today thinking I'm going to try and limit my losses, thinking about the days to come. To go through the finish line with the fastest time I really didn't see it coming," he said after stage 17 from Embrun to Chorges.
There has been a mild shake-up in the overall standings after the final individual time-trial of the race. Bauke Mollema (Belkin) was the biggest loser. He started the day second overall and 4:14 down on the Briton Froome, but is now fourth and 6:23 in arrears.
Tejay van Garderen (NMC), Alejandro Valverde (Movistar), Joaquim Rodriguez (Katusha) and Contador were amongst those to set benchmarks throughout the race before Froome stormed home.
Jean-Christophe Péraud (Ag2r-La Mondiale) in an act of brave defiance started stage 17 with a fractured collarbone he sustained in a crash on the first of two descents in a reconnaissance ride.
Péraud crashed some 2km from the finish in the actual race and was forced to abandon.
Tour de France 2013, stage 17: Embrun to Chorges, 32km individual time-trial
1. Chris Froome (Sky) 51-33
2. Alberto Contador (Saxo-Tinkoff) at 9secs
3. Joaquim Rodriguez (Katusha) at 10secs
4. Roman Kreuziger (Saxo-Tinkoff) at 23secs
5. Alejandro Valverde (Movistar) at 30secs
6. Nairo Quintana (Movistar) at 1-11
7. Michal Kwiatkowski (Omega Pharma-Quick Step) at 1-33
8. Jakob Fuglsang (Astana) at 1-34
9. Andrew Talansky (Garmin-Sharp) at 1-41
10. Tejay van Garderen (BMC) at 1-51
Overall classification after stage 17
1. Chris Froome (Sky) 66-07-09
2. Alberto Contador (Saxo-Tinkoff) at 4-34
3. Roman Kreuziger (Saxo-Tinkoff) at 4-51
4. Bauke Mollema (Belkin) at 6-23
5. Nairo Quintana (Movistar) at 6-58
6. Joaquim Rodriguez at 7-21
7. Laurens Ten Dam (Belkin) at 8-23
8. Jakob Fuglsang (Astana) at 8-56
9. Michal Kwiatkowski (Omega Pharma-Quick Step) at 11-10
10. Daniel Martin (Garmin-Sharp) at 12-50
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