Vincenzo Nibali extended his general classification lead on Friday, but he will need to double his effort in the 14th stage of the 2014 Tour De France 2014 Saturday as they are facing a more difficult climb in the Alps.

Nibali launched a perfectly-timed attack with less than seven kilometers left on the 13th stage, leading to a crucial win that put him three minutes, 37 seconds ahead of second-running Alejandro Valverde.

The 14th stage on Saturday is expected to lead to a major shakeup in general classification -- either Nibali will extend his lead or the riders trailing him will move closer to his total time.

The peloton is facing a 177-kilometer race from Grenoble to Risoul, which will feature two category one climbs and a Hors category climb, which are way more difficult than the climbs in the previous stage.

The riders will face a Category One, 1,502-meter climb midway through the race and another Category One climb toward the end of the race. But it would be the Hors category climb sandwiched between the two Category One climbs that could prove to be vital for the leaders because it towers at 2,360 meters, which is way more complicated than the 1,730-meter climb in the previous stage.

"This will be another hard day in the saddle and it could prove interesting because we go over 2,000m twice in one day and altitude affects different riders in different ways. We are right into the thick of the race now and there will be tired bodies. It's another day for the main contenders," Team Sky's Geraint Thomas said via BBC.

How to Watch, Maps, Standings

Cycling fans can catch the 14th stage on NBCSN and via online streaming through NBC Sports Live Extra.

The full route map is available at LeTour.com, while the updated standings are available on this link. Below is the current general classification top 10 heading into Saturday's 14th stage:

General Classification, Top 10

  1. Vincenzo Nibali (Ita/Astana) 56hrs 44mins 03secs
  2. Alejandro Valverde (Spa/Movistar) +3mins 37secs
  3. Romain Bardet (Fra/AG2R) +4mins 24secs
  4. Thibaut Pinot (Fra/FDJ) +4mins 40secs
  5. Tejay van Garderen (US/BMC Racing) +5mins 19secs
  6. Jean-Christophe Peraud (Fra/AG2R) +6mins 06secs
  7. Bauke Mollema (Ned/Belkin) +6mins 17secs
  8. Jurgen Van den Broeck (Bel/Lotto) +6mins 27secs
  9. Rui Costa (Por/Lampre) +8mins 35secs
  10. Leopold Koenig (Cze/NetApp Endura) +8mins 36secs