Tom Dumoulin (Sunweb) says that the 2019 Tour de France route disappointed him, pushing him to race the Giro d'Italia in May.
The Dutchman, second overall in both grand tours in 2018, is aiming to repeat his 2017 Giro win and to return to the Tour in July.
However, he was thinking about a focused Tour push until the organisers revealed the route in October.
"My chances of winning the Giro this year is simply many times greater than winning the Tour," he said at the team's presentation on Thursday (January 3).
The Giro features 58.5 kilometres of time trial versus 54 in the Tour de France, but half are in an individual TT.
Each of the Giro's three time trials are all individual, which should suit the 2017 world champion.
"The course of the Tour was announced when I was in the middle of the mountains of Nepal for my honeymoon. I was in a cabin at 3000 meters with my wife, but we finally had some WiFi, so I turned on my phone for a while and I was a bit disappointed with the Tour course."
Dumoulin raced consistently through the 2018 Tour and pushed Geraint Thomas (Team Sky) until the time trial, stage 19.
He managed second overall at 1-51 minutes behind Thomas, his best finish yet.
He and general manager Ivan Spekenbrink began plotting a course towards the 2019 Tour beginning in Brussels. On October 25, when the Tour route became public, that changed. The Giro route presented a week later served to confirm their decision.
"Actually, it was already certain that we would put everything on the Tour in 2019," Dumoulin explained. "But after the Tour presentation, I suddenly started to think whether that was a smart idea, I wrote [to the team]: 'Before you make a decision, we still need to talk.'"
"The team finally made the decision. It was a difficult choice because I know that I don't have many years to win the Tour, but 2019 is just not a good year for me to put everything on the Tour."
Team Sky's Chris Froome will not return to the Giro after winning ahead of Dumoulin in 2018. He will race the Tour alongside 2018 winner Thomas.
Big stars going to the Giro include Vincenzo Nibali (Bahrain-Merida), Simon Yates (Mitchelton-Scott), Mikel Landa (Movistar) and Sky's Egan Bernal and Gianni Moscon.
"There are a lot of strong riders going to the Giro with Simon Yates, Primož Roglič, Egan Bernal and Vincenzo Nibali. I will be one of the favourites in Italy," Dumoulin added.
"I'm very enthusiastic about the plan to make the Giro the main goal again, because I think that's the best Grand Tour.
"I realised, especially after last year, that I really want to win the Tour once. That would be the ultimate and that dream has become realistic now. I hope to ride very well in the Tour, but this was not one of the right years to focus on it completely. "
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