The Italian Grand Tour star of Bahrain-Merida on Monday previewed some of the 15 cobbled sectors. The 21.7 kilometres of bad farm roads feature within the 154-kilometre ninth stage on July 15 from Arras to Roubaix.
"Some sectors are really difficult. And if it rains like in 2014..." Nibali told La Gazzetta dello Sport newspaper Monday evening after his reconnaissance.
He rode in the car with sports directors Rik Verbrugghe and Tristan Hoffman for the first three sectors. Afterwards, he and team-mate Franco Pellizotti mounted their Merida bikes to ride to Roubaix.
"Compared to 2014 and 2015, I found some of the sectors more dangerous," Nibali continued. "And they will be even more so if it rains. In some there was so much water on the side, and so much mud."
In 2014, due to the rain overnight at that morning, organiser ASO cut the kilometres of cobbles by three to 13. Tour star Chris Froome crashed the day before and twice ahead of the cobbles, forcing him to abandon.
Nibali dominated the stage by taking nearly two minutes over his rivals.
In 2015, the Tour de France riders covered 13.3 kilometres over the famous cobbles that feature in the Paris-Roubaix every year.
To be ready for 2018, the stars are visiting the sectors to see what they are going to face. Movistar's leaders Mikel Landa, Nairo Quintana and Alejandro Valverde went recently, while Froome was there in late March.
"In comparison to the recent years, we have more kilometres on the pavé. It will undoubtedly be one very important stage," Nibali said.
"As soon as I can fit it in, I want to carry out another reconnaissance."
Nibali is perhaps the most adapted on the cobbles, which he showed in the 2014 Tour and in the recent Tour of Flanders.
He followed his surprise Milan-San Remo solo victory with his usual grit in Flanders. He attacked after the Kruisberg at 28 kilometres to race, which was followed by the eventual winning move from Niki Terpstra (Quick-Step Floors).
"Before he quits, he'll race Roubaix," Nibali's trainer and team sports director Paolo Slongo told Cycling Weekly last month. "It's in his head, the idea is there. He'd race without any stress or pressure, just for fun.
"Could he win all five Monuments? He could potentially win a little of everything. On the pavé, he handles himself. But he remains a stage racer with an ability for a certain type of one-day races. Flanders or Roubaix, for his weight, are not exactly suited, but you never know."
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