0km - Win number 25 for Mark Cavendish - but the story of the day was those crosswinds and splits... quite astonishing stuff.
0km - New top five: 1. Froome, 2. Mollema +2:28, 3. Contador 2:45, 4. Kreuziger 2:48, 5. Ten Dam +3:01
0km - Valverde will drop out of the top ten tonight - his group are set to arrive eight minutes in arrears, maybe more...
0km - The yellow jersey group crosses the line 1:08 down! Andre Greipel leads them over, and that's a big loss for Chris Froome...
0km - Mark Cavendish takes an easy win ahead of Peter Sagan, with Bauke Mollema in third.
0km - CAVENDISH TOO STRONG! A second win for the Manxman...
0,5km - Chavanel leading out the sprinters - who has the legs?
1km - Back together under trhe banner... now Chavanel on the front with Sagan and Cav on his wheel.
1.5km - With Sagan marking Cavendish at teh back, Niki Terpstra goes for a long one!
2km - Now it's getting a bit tactical because it's not just Saxo wanting to maintain the gap, but OPQS and Cannondale sniffing out the stage win...
3km - It's still a Saxo-Tinkoff time trial on the front as we enter the final three kilometres....
4km - Eight minutes for the Valverde group now! All because of an untimely puncture...
6km - Froome has no Sky team-mates left - they have all blown, with the exception of Geraint Thomas it seems. But the yellow jersey is on his own, 10 back, in the pack. The gap is now one minute.
7km - The leaders have 55 seconds now on this uphill grind. Cavendish is digging deep and looks knackered, with Sagan in his wheel.
8km - Still Saxo drives the pace - and Contador is right to urge on the others, for Belkin's Mollema and Ten Dam will rise up in the standings too.
9km - We're approaching that climb and Sagan is coming foward while Contador is rallying the group, urging them not to give up.
10km - Under the 10-to-go banner and the leaders have 40 seconds.
11km - Remember, there's that small climb coming just up before the finish. OPQS may launch Chavanel as a Plan B - while Sagan could go for a long one too...
13km - Lotto Belisol are also trying to close the gap for their man Greipel. Froome has a stony expression as he rides in the wheel of Greipel. Saxo are driving hard, but the gap is still 38 seconds so it's not getting any bigger.
14km - Sky have three riders leading the chase and they have reduced the gap to 40 seconds. The Valverde/Kittel group is more than six minutes in arrears now, with the Voeckler grupetto at almost 10 minutes.
16km - The 2013 Tour de France really needed a day like this - and now the lead is 45 seconds for the escapees. Chris Froome will be getting nervous...
19km - It's up to 30 seconds now for the Contador/Cavendish/Mollema/Sagan group over the yellow jersey pack. BMC have called off the chase so it's up to Sky now to close the gap. It's now five minutes back to the Valverde group!
22km - Saxo Bank are really giving it there all - he's benefitting from all these splits, and will be in the top three tonight after Valverde's wobble. Cavendish has Terpstra, Chavanel and Martin and has to be the favourite for the win if this group stays out. They have 20 seconds on the pack, so it's not a given. Meanwhile, Valverde's group is now a huge 4:40 down.
25km - The Valverde group is now a huge 3:35 down on the leaders now. He is going to plummet down the overall standings tonight.
26km - The gap is 10 seconds for the leading group, who have numerous Saxo and OPQS riders inside. The likes of Rogers, Roche and Kreuziger are there for Contador, while Cavendish has two or three team-mates, including Terpstra. Sagan has just one Cannondale team-mate.
30km - We have about 15 riders in this leading group, including Mark Cavendish, Peter Sagan, Bauke Mollema, Laurens Ten Dam and that man Contador.
31km - YELLOW JERSEY DISTANCED! Saxo Bank-Tinkoff combine on the front and force another split - and this time, Chris Froome does not manage to stay with them. Richie Porte has already been dropped, so Froome has no help from him, whiel Edvald Boasson Hagen is, of course, out after his crash yesterday.
36km - The gap has grown again to 2:20 for the Kittel/Goss/Valverde group and it looks like it won't come down before the finish. There are two smaller groups off the back of the main pack, including one around Juan Antonio Flecha and another around Richie Porte.
40km - Sylvain Chavanel, on his orange bike, is right on the front alongside Tony Martin and a load of Belkin riders.
42km - The Valverde and Kittel groups are back together, now 1:50 down on the main pack.
45km - Cavendish is back with his team-mates on the front...
47km - And now it seems like Cavendish is being distanced by the first group - which has split in three! Extraordinary scenes here in central France. There are groups of riders all over the road. This is quite unexpectedly brilliant.
50km - It's all got rather confusing. A splinter group has formed off the front of the Kittel group including Valverde, Stuart O'Grady, some Euskaltel riders, a Lotto and a cluster of Europcar (including Pierre Rolland following his puncture). They are 45 seconds down on the pack, and 15 seconds ahead of the Kittel group. Thomas Voeckler's grupetto rolls along more than five minutes down...
52km - Puncture for Pierre Rolland, who swaps rear wheels with Yohann Gene before getting back on his way.
53km - Australian Matt Goss is in the second group too - which explains why Orica-GreenEdge are back there leading the chase with Movistar.
55km - Despite Omega Pharma-Quick Step's best efforts, the gap is coming down... Just over a minute as the leaders pass through the town of Issoudun.
60km - The gap for the Kittel-Valverde group is now 1:41. Quite extraordinary.
62km - At the first intermediate sprint at Saint-Aoustrille, it's Mr Intermediate Andre Greipel who takes maximum points ahead of Mark Cavendish, the green jersey Peter Sagan and, I think, Kris Boeckmans.
65km - Movistar have made some ruthless decisions following that puncture to Valverde: at first both Nairo Quintana and Rui Costa (8th and 9th on GC) stayed with the main group, but then Costa, the Portuguese Tour de Suisse winner, was ordered back, much to his discontent. So they only have the Colombian Quintana in the main group now...
69km - The Valverde-Kittel chasing group is now 1:20 behind the main peloton.
70km - No one expected such a fast and frenetic aspect to today's stage. At first it was an attempt for the OPQS team to distance their rival Kittel - but now it has become a Belkin attack on Movistar and Mollema's podium rival Valverde.
75km - Europcar - and most notably Mario & Luigi (Rolland and Cousin) - are also contributing to the pace setting on the front, bizarrely. They don't really have anything to play for - except not dropping off the back of the pack themselves. But given Rolland's lowly place on GC, it's odd they're giving it so much welly.
78km - The Valverde group are actually going backwards now, with Belkin sensing blood: both Mollema and Ten Dam could profit from this in the general classification. The cluster of Movistar riders will soon be caught by the Kittel chasing group. They are 40 seconds adrift now.
82km - The Valverde sextet (all Movistar) are 12 seconds behind the pack with the Kittel chasing group at 55 seconds. Belkin and Omega Pharma still set the fierce tempo.
86km - PUNCTURE FOR ALEJANDRO VALVERDE! The Spaniard swaps a wheel with a team-mate and is now surrounded by Movistar riders trying to pace him back - but he's already 35 seconds down on the leaders and rides in between them and the Kittel group. It's app happening.
88km - The Kittel chasing group is now 1:15 in arrears. The main pack is now coming to the feed zone - this will be interesting...
90km - Omega Pharma-Quick Step are still giving it their all on the front - as are Saxo Bank. Despite earlier reports, Andre Greipel is in this main group, so it's just Marcel Kittel of the big sprinters who has missed the split.
95km - That was an extremely generous of the race organisers to give the Cote de Crotz a Cat.4 status - it was merely a small mound in the road. Anyway, Pierre Rolland is allowed to ride clear and take the point to consolidate his lead in the polka dot jersey standings by a solitary point. Rolland, who's race strategy seems now to make it to Paris dressed entirely in red spots, now has 50 points and leads Froome by 17 points in the KOM standings.
96km - It's all over for the six leaders, who must have wondered what hit them. The main pack now has one minute over the Kittel group and a further 30 seconds over the smaller Voeckler group. All the big favorites for the GC are here in the main group as we approach the first and only climb of the day...
98km - If Kittel is concerned he doesn't look it. The German is tucking into a cereal bar as he rides along in the second peloton after that split.
100km - Belkin have come to the front to join the pace setting with OPQS. They have reduced the gap of the six escapees to just 40 seconds, but more inportantly, they have put 45 seconds into the Kittel group and 1:30 over the Voeckler group.
102km - The upshot of this increase in pace means that the break's lead has been whittled down to just one minute.
105km - One reason why Omega Pharma-Quick Step are pushing hard is because both Marcel Kittel and Andre Greipel are in the second peloton. The German sprinters got caught napping there...
108km - Some of the names from the second group include the likes of Pinot, Taaramae, Gilbert, Coppel, Le Mevel and Hoogerland...
110km - SPLITS IN THE PELOTON: A combination of the wind and Omega Pharma-Quick Step's pace setting has created mayhem in the peloton, which has split into numerous groups on this long, rolling, straight road through the Tourraine. The likes of Thomas Voeckler, Thomas de Gendt and Damiano Cunego ride in the third peloton almost one minute back. The yellow jersey is safe in the main pack.
115km - Of these escapees, three have already been involved in breaks so far in the Tour: Lemoine (stage one), Perez (stage two) and Mate (stage six and 10).
122km - The escapees have reached the town of Coulangé at the 50km mark of today's stage. It's a milestone: the 2013 Tour has now gobbled up 2013 kilometres. Just 1,391 to go (and some mountains) until Paris.
125km - The average speed for the first hour of racing today was 44.5kmh for the leading sextet of riders. Back with the bunch, Mark Cavendish has problem with one of his cleats and is having it checked out by a mechanic as he holds onto his OPQS team car.
130km - The big battle today will not only be for the stage win but also the green jersey points. By not contesting the final yesterday, Andre Greipel was leap-frogged by Mark Cavendish, who now trails Peter Sagan in the standings by 96 points. Greipel is a further 16 points back. Marcel Kittel, although he's won three stages, is only in fourth place, a huge 130 points down on Sagan, who looks all but sure of retaining his green jersey in Paris.
135km - The lead is up to 3:20 for the six escapees now - and Alberto Contador, fourth on GC, has just punctured and needs a wheel change. He's riding back onto the peloton with his Saxo-Tinkoff team-mate Sergio Paulinho.
140km - There is a punchy climb 10km from the finish today - but it shouldn't be enough to shed the pure sprinters. Sure, there will be a bit of a shake up, but there's no reason to think it won't come back together by the end. Although, the approach to Saint-Armand-Montrond is rather technical and with numerous bends - and so should one rider get clear, he could fancy his chances...
145km - There's just the one categorised climb today coming just ahead of the half-way point. It's just a Cat.4 mound and so won't have any bearing on the KOM standings. Pierre Rolland is the current polka dot jersey with 49 points to Richie Porte's 33.
150km - Should this break stay out all the way then Europcar's Yohann Gene would be the danger man at Saint-Amand-Montrond: he finished 10th in the bunch sprint on Tuesday and then 8th yesterday. Gene, the 32-year-old sprinting domestique, is clearly finding his legs in the second week of the Tour. The gap for the leaders is now 2:30.
155km - Yesterday, the peloton allowed the break to build up a huge nine-minute lead. They're not making the same mistake twice: the six leaders have just 2:10 to play with and the gap is not increasing very fast.
160km - The temperature is already up to 27 degrees. It's another hot day for the riders. So far, not a drop of rain has fallen on the roads of France during the Tour - in stark contrast to May's sodden Giro d'Italia.
164km - The gap is two minutes for the six escapees.
165km - It was the Polish rider Niemiec who instigated the attack - and he's the best place on GC in this group, just under 25 minutes down on Chris Froome.
170km - BREAK: Six riders are out ahead after an attack from the outset. They are Przemyslaw Niemiec (Lampre-Merida), Yohann Gene (Europcar), Ruben Perez (Euskaltel), Luis Mate (Cofidis), Kris Boeckmans (Vacansoleil-DCM) and Cyril Lemoine (Sojasun).
173km - They're off! Christian Prudhomme waves his flag from the luxury of his red Skoda and we're on the road for stage 13 of the 100th Tour...
12:35 - The remaining 181 riders are currently riding through the neutral zone at the start of today's stage. Just the one rider to retire after that big pile-up yesterday - Boasson Hagen. It's another sunny day, with temperatures in the mid 20s.
12:30 - Britain's Chris Froome managed to keep up and avoid the pitfalls of an incident-filled final kilometres, but the yellow jersey did lose Sky team-mate Edvald Boasson Hagen, who crashed out of the race with a broken right shoulder. Froome still leads Alejandro Valverde by 3:25 and Bauke Mollema by 3:37 on GC but losing his second team-mate - and someone with such a big engine as the Norwegian - will be a blow for the race leader.
12:25 - Yesterday, Germany's Marcel Kittel won his third stage of the Tour with a superb late surge to deny Britain's Mark Cavendish. Both sprinters avoided a pile-up 2km from the finish that held up German national champion Andre Greipel. It was an historic third consecutive stage for Germany - and a fifth in total in the 100th edition of the race. Amazingly, we are still awaiting wins for Italy, Spain and the host nation France.
12:20 - Welcome to live coverage of stage 13 of the Tour de France, a largely pan-flat 173km trek through the Tourraine and Berry regions from Tours to Saint-Amand-Montrond, which is pretty much dead in the centre of France. It's another day for the big bunch sprinters to come out and play... which generally means a win for Marcel Kittel is on the cards.