Hello and welcome to live coverage of stage 20 of the Tour de France - the all-important short and sharp 110.5km ride from Modane to Alpe d'Huez. The riders tackle two monster climbs - the Croix de Fer and the famous 21 hairpin bends of Alpe d'Huez, the Dutch Mountain.

Nibali has three Astana team-mates with him - but this will dent his chances of taking Valverde's place on the podium.

Puncture for Nibali! Karma, perhaps, for the Italian who needs a bike change just before the start of the climb for the pack.

Lars Bak has been dropped straight away on the climb...

Did you know: Only one rider has ever crested the summit of Alpe d'Huez in pole position and not won a stage on the Tour: Italian Moreno Moser, who led the race over the first of two Col de Sarenne-sandwiching ascents of Alpe d'Huez in the centenary race in 2013.

We're onto the final climb to Alpe d'Huez - it's an hors categorie ascent of 13.8km at 8.1%.

Two Lampre-Merida riders here in Serpa and Plaza, and two Cannondale-Garmins with Hesjedal and Navardauskas, who takes second place in the intermediate sprint when they zip through.

Geniez has passed through the intermediate sprint. The climb is about to start for him...

The chasing group is now nine strong after that duo were caught: Pinot, Rolland, Plaza, Serpa, Hesjedal, Anacona, Navardauskas, Bak and Edet. They are 2:10 down on Geniez and 1:35 ahead of the pack.

Not long to go until Dutch Corner...

The Rolland group is closing in on the Bak/Edet duo. They are 2:25 down on the lone leader, with the peloton at four minutes. Finely balanced ahead of this final climb of the Tour.

There's a bit of a headwind which will make it different for Geniez. He was ninth in the Giro and he's 4:08 ahead of the yellow jersey group. Will it be enough?

Geniez has completed the descent and is riding alongside the Lac du Verney en route to Bourg d'Oisans. The Rolland chasing group have caught Navardauskas so the Lithuanian joins his Cannondale-Garmin team-mate Hesjedal to give them a numerical advantage of sorts.

Geniez is being chased by Bak and Edet, who are 1:40 down on the Frenchman. Navardauskas is a bit further back, then the six-man Rolland group is at 3:15 and the yellow jersey group at 4:05.

Believe it or not: Winner on Alpe d'Huez in 2006, Frank Schleck's absence in this year's race owing to injury means this Tour will be the first in a decade without either of the Schleck brothers. Younger brother Andy famously won on the Galibier in 2011 - and was first over the summit one day later en route to Alpe d'Huez - before injury forced him to retire early from the sport.

Geniez has gone over the brow and is on the next section of the descent. The temperature is down to 19 degrees Celsius for now.

Froome now has four Sky team-mates in Thomas, Poels, Roche and Porte. They trail the lone leader Geniez by 3:45 with the Rolland group 40 seconds further ahead. Rolland is wearing the red dossard as yesterday's most agressive rider.

Winner at Alpe d'Huez in 2011, Pierre Rolland (Europcar) and moustachioed José Serpa (Lampre) have joined Pinot, Anacona, Plaza and Hesjedal on this uphill section.

Geniez is on a slight uphill segment that cuts this descent in half. You sense that there will be further regrouping on the 15km flat segment in the valley ahead of today's showpiece final climb. Can Quintana make up 2:38 on one climb? It's highly doubtful - but he'll no doubt try, and perhaps win the stage in doing so.

Pinot has joined a four-man chasing group on the descent with Hesjedal, Anacona and Plaza. Lone leader Geniez still has 3:20 over the main pack.

There's a bit of regrouping on this descent with Froome now having three Sky team-mates with him, plus the likes of Contador, Rodriguez, Bardet, Pinot, Frank, Talansky, Gesink, as well as the Movistar duo of Quintana and Valverde.

Froome took 8pts over the Croix de Fer in the KOM competition while Bardet took none - so the yellow jersey is also the polka dot jersey with 95 points to Bardet's 90 ahead of the final climb. There's a maximum of 50 still left up for grabs today.