Chris Froome’s carbon-fibre bike was one of half a dozen examined after the finish here by commissaires looking for the hidden electric motors that are to cycling what the Loch Ness monster is to the natural world.

Rumours of motors have been constant over the past five years, but there have been no sightings to date, and, as is par for the course when inspections are carried out, there was not a cog nor a battery hidden anywhere in Froome's machine, nor that of the stage winner, Romain Bardet, nor points leader Peter Sagan.

It would therefore be inappropriate to say Froome is motoring to victory on Sunday, but there was a collective air of resignation about his rivals as the race entered the mountains of Savoy.

Alberto Contador strove manfully, but is stiff and sore after his crash on Wednesday, Nairo Quintana was curiously restrained on terrain that should favour him, while Alejandro Valverde looked focused on defending his third place overall from the ever-present and still surprising Geraint Thomas. As for Vincenzo Nibali, down in seventh, he is a shadow of the man who dominated the 2014 race.

There remain five huge mountains to climb before the 20th stage is completed on Saturday afternoon at l’Alpe d’Huez, at which point Froome can truly consider his second Tour, with its Sunday finish in Paris, in the bag.

Thomas key to Sky success

Thomas has been one key to Sky’s dominance as he has barely faltered at Froome’s side in the highest mountains. If he maintains his current form, his dissuasive presence will continue to work on the minds of Quintana, Valverde et al, and if the latter fades as he did last year, the Welshman could be pushing for a place on the podium.

It was Thomas who upped the pace at the key moment close to the top of the Glandon, a 21.7km monster which, with its sister col, the Croix de Fer, will be covered three times in three days due to the diversion of Saturday’s stage because of a landslide. The crowds were understandably immense – they have only to park their camper vans for a three-day viewing fest – and there was potential drama to witness.

Contador finally made a clean break 7km from the top, gaining almost a minute before Nibali and Quintana probed in their turn closer to the top.

“We didn’t panic,” Thomas said. “Contador is at six minutes, so we didn’t have to react straight away.”

Froome added: “Two years ago, at this point, I was hanging on; this time I feel in control of the situation. I’ve got two wheels to look out for: Quintana and Valverde.” He spoke with the tone of a man who feels the job is almost done.

Thomas’s steady riding brought all three within reach by the summit, and that was that in the battle for the overall standings. The stage win, however, was a different matter. AG2R-La Mondiale’s Bardet (24) is one of the up-and-coming generation of French cyclists, together with Thibaut Pinot, and he has been out to reassert himself since his poor showing at La Pierre-Saint-Martin cost him the chance of repeating his sixth place overall in last year’s Tour.

He was outwitted at Mende by MTN-Qhubeka’s Steve Cummings, but showed admirable ruthlessness atop the Glandon.

Collision

As he raced clear of the leaders, the Dane Jakob Fuglsang collided with a race motorbike, which was later banned for poor driving, and fell heavily.

The eventual second-placed rider, Pierre Rolland, stalled briefly, but Bardet’s view was: “I’m sorry for [Fuglsang], but I have to go now.”

Bardet was never likely to be seen again, even though Rolland and Gautier chased manfully over the final nasty surprise of the day, the tightly packed hairpins of the Lacets de Montvernier, a climb so narrow it was closed to the public.

His reward was a second stage win for his team and an option on the King of the Mountains prize, where he is now level on points with Spain’s Joaquim Rodríguez, who leads on countback.

The polka-dot jersey could be decided on today’s contorted loop, which takes 138km to travel. Sadistically, it repeats some of yesterday’s terrain in the opposite direction to make up the toughest of the Alpine stages.

(Guardian Service)