'It's about being aggressive when it counts': Geraint Thomas's guide to the 2017 Tour de France route

Team Sky's Geraint Thomas expects a "tough" Tour de France route over the next three weeks helping Chris Froome towards a fourth title.

The route includes only three true summit finishes and several stages that end with a downhill run. Organiser ASO only included two time trials this year, stages one and 20, totalling 34.5 kilometres.

>>> Tour de France route 2017: stages and key climbs

"It's a tough race, not a massive amount of TTs – and Froomey would prefer to do longer TTs," Thomas told Cycling Weekly.

"You have to be shape from start to finish. I think it's going to be an exciting few weeks.

"There could be someone on the podium who might have lost two to three minutes in the first week, but gets a bit of leeway and then suddenly he's there. If someone is willing to be aggressive and take it on, then it will work to his advantage."

ASO created a route which awards aggressiveness. Already on stage five it included the first summit finish to La Planche des Belles Filles. But later on, stages eight and nine, it's added a twist.

Stage eight to Station des Rousses ends with 12 kilometres of undulating – flats and downhills – after the summit to Montée de la Combe while a brutal looking stage nine climbs to Mont du Chat, bombs downhill and covers 13.5 flat kilometres to Chambéry.

"That's the big change [with only three summits and less time trial kilometres]. Every week, this year has a summit finish and a steep tough stage,” said Thomas.

"Stages eight and nine are not mountain tops, but one of them you can still make time differences on. A few guys will try and get gaps and long as they don't descend slowly, they can keep any advantage they have at the top.

"And then you have the real short stage [stage 10 to Foix]. It is only 100K and I bet it'll be full-gas all day.

"Then days like the Galibier stage [17]. We previewed that stage, and it's not a massively technical descent [19 kilometres] to Serre Chevalier. If someone has the advantage there then he can hold threat advantage to the line."

The race starts Saturday with a short 14-kilometre time trial through Düsseldorf. After a flat stage Sunday, the fireworks could begin with the short and steep Longwy finish on Monday back in France.

"You have to be aggressive but also remember that it's a long way," Thomas continued.

"That's the thing with Froome, we always have to hold him back. He always wants to attack anywhere, in the crosswinds, in the downhill, or on the first climb of the day. It's about managing that, being aggressive when it counts and not being carried away."

Chris Froome won the Tour in 2013, 2015 and 2016. In 2014, he abandoned due to crashes in the first week.

He appears to be improving just in time for July, but the 2017 season has been his most unsuccessful since he became a Grand Tour challenger. He has yet to win this year, leading some to wonder if Richie Porte (BMC Racing), Nairo Quintana (Movistar) or another star may topple Froome.

"I think he still looks good and I don't think he's too far off his best," continued Thomas.

"In the Dauphiné he made that step up. I think he's still going to be as good as ever, but the gap to the other guys has come up over the years.

"But the fact that he hasn't won gives his rivals a confidence boost, which obviously isn't a great thing, but at the same time, he's going to be good and fighting for the win."

Thomas will become Sky's plan B if something should happen to Froome. He is racing the Tour after pulling out of the Giro d’Italia early due to a crash.

Team Astana leads with Fabio Aru and Jakob Fuglsang, who won the Critérium du Dauphiné in a tactical battle with Porte.

Orica-Scott has two leaders, too, with Colombian Esteban Chaves and British rider Simon Yates.

"Given the depth in the race, a lot can happen and change. It'll be an exciting few weeks," Thomas said.

"There's always [that depth]. After you get the first 10 days or two weeks done, there is a natural selection and the cream rises to the top. It'll be between two to four men, but I wouldn't be surprised if it comes down to the final time trial in Marseille."

After the final 22.5-kilometre time trial in Marseille, the race finishes with its traditional flat sprinters' stage on the Champs-Élysées in Paris.