TdF Stage 18 Preview: Sudden Impact...

It's been a good while since La Grande Boucle included an uphill time trial, and we can't wait.

Porte: "I need to have a good time trial and take some time." Source: AFP

The route for the race of truth... Source: ASO

It comprises just 2.5 kilometres of today's stage but the winner will be decided by who rides best on the Côte de Domancy.

Hinault: from this sorry sight at the 1980 Tour de France... Source: Getty Images

The climb was part of the course at the 1980 road world championships in Sallanches, regarded as the toughest of all time. Bernard Hinault, regarded as somewhat of an outsider after exiting that year's Tour due to tendonitis, decided to go early; on the thirteenth of twenty ascensions of the Domancy, he attacked with Belgian Michel Pollentier to produce a selection of five riders - then methodically proceeded to destroy them till only he remained in front. The first Frenchman since Jean Stablinski in 1962, he would win by over a minute from Italy's Gianbattista Baronchelli, the only other surviving member of the break.

... to world road champion in Sallanches. Source: Getty Images

As for his tendonitis? For his rivals no such luck: 'Le Blaireau' would win another six Grand Tours including three more in July.

... and Tour champion the very next year. Source: AFP

More recently, it was used as part of the final stage of the 2010 Critérium du Dauphiné. A break of thirteen entered the same finishing circuit as used at the 1980 Worlds, which saw them tackle the Côte de Domancy five times. Once again, the 9.4 percent climb had done its job, leaving just five by the penultimate lap. But rather than wait for the sprint as many predicted, 23-year-old Edvald Boasson Hagen, riding for Team Sky, went the way of the Badger 30 years prior and soloed into Sallanches.

Edvald Boasson Hagen wins the final stage of the 2010 Critérium du Dauphiné. Source: AFP

Today, the peloton will have no one to fear other than themselves.

It said a Grand Tour contender must be able to climb and time trial, and it is here we will see them do both. It’s hard to say whether this stage favours the climber or rouleur because even though it’s a mountain time trial it’s not a ‘mountain’ in the strictest sense: “This is not a steady climb,” says technical director Thierry Gouvenou in the official Tour guide. “The key to success will be adapting to changes in rhythm.”

“The key to success will be adapting to changes in rhythm” Source: ASO

Once Domancy is done, there are another eight kilometres of uphill to the top of the Côte des Chozeaux before a 2.5km descent into the posh ski resort of Megève, France's answer to Aspen. “In all honesty, we’re not expecting big gaps: something like 20 to 30 seconds between the favourites for the podium,” predicts Gouvenou.

We’re not so sure... History tells us that a time trial in the third week often produces significant gaps between those on the leaderboard because accumulated fatigue affects different riders in different ways on different days. Even the time trial to La Caverne du Pont-d’Arc a week ago, designed to keep the climbers in contention, produced sizeable differences: over 37.5km Froome, the maillot jaune, finished just over two minutes ahead of Richie Porte and Nairo Quintana, and a cavernous 3’43 in front of Joaquin Rodriguez, jettisoning any hopes of a high overall finish for Purito. To flounder on this day will almost certainly mean to founder in the fight for the overall.

Nonetheless, Gouvenou did acknowledge that “the psychological impact will be substantial. Whoever wins the stage will look ahead to the final two stages in the Alps with greater peace of mind.”

Stage 17, 2013 Tour: Froome is a proven performer in final week time trials. Source: Tim de Waele/Getty Images

Christian Prudhomme, Tour de France race director, says...

“The format isn't that frequent on the Tour but it fits in perfectly to the four-day Alpine sequence of the race. Before reaching Megève, the best climbers among the rouleurs or the best rouleurs among the climbers will find a terrain to express themselves on the tough Côte de Domancy and then in the Côte des Chozeaux.”

What they say...

Chris Froome (Team Sky)

"Things can still happen and the time trial will be a big deal."

Richie Porte (BMC Racing)

"I quite like uphill time trials so I think it's a crucial one. I know I need to have a good time trial and take some time. I think I've shown (on Stage 17) that I'm climbing well, so I take confidence out of (that)."

Daniel Martin (Etixx-Quick-Step)

"I remain confident and hope for some nice results in the next three days in the mountains."

Tejay van Garderen (BMC Racing)

"I think I'll use the TT as a recovery day; as much as I can, anyway. And then I'll do what I can to help Richie."

Weather: After potential night storms Wednesday night there might be showers in the morning. A quick improvement will grant sun during the time trial between Sallanches and Megève. Temperature between 24-32°C in Sallanches and 18-26°C in Megève. Very windy between Sallanches and Domancy.