Team Sky Sport Director Nicolas Portal believes there will be only a limited amount of opportunities to gain time at the 2017 Tour de France, after the route was announced by race organisers ASO.

Portal was in attendance at the route presentation with reigning champion Chris Froome and, speaking afterwards, he declared the route 'good' for the team, but warned that any time losses will be punished heavily.

With just three summit finishes on the route and only 36 time trial kilometres - including an opening prologue - the general classification race is set to be one of the tightest in years.

Portal told TeamSky.com: "In general, we know it is always hard and interesting, but there are some big Alps and Pyrenees stages missing this year. That doesn't mean it's going to be easier though.

"It's a Tour where if you lose a bit of time, it will be pretty hard to bring it back on GC. In years gone by there have been big, big mountain stages where you could say OK that one wasn't very good for me, but let's wait two or three days and we can maybe do something again, gain some time back. But in this Tour, if you start to lose time, it will be pretty complicated."

The race will start in Dusseldorf, Germany, and move onto Belgium and Luxembourg, before reaching France on day four. The route will take in all five of the mountain regions in France yet it features less HC, first or second category climbs than the 2016 race - 23, compared to 28.

Portal is already eyeing up the race's first summit finish, atop La Planche des Belles Filles - where Froome won his first Tour stage in 2012 - on stage five and Portal believes that will create early splits between the contenders.

"That will be the first proper summit finish," he added. "That will clearly be really hard and you will quickly see which five or six guys will play out the GC. If you can gain some seconds there then you need to do it. Obviously if you got the yellow jersey there it's pretty far from the finish, but as a team you would deal with that situation."

After the opening prologue blast around Dusseldorf the time trial bikes won't come out again until stage 20, for a 23km test against the clock in Marseille.

"The time trial in Marseille will be hot and it is quite short, with a small climb in the middle of the parcours. It will be all about what is left in the tank after a long three weeks.

"The Tour is OK for Chris. It would be nice if we had more time trial kilometres because he is good at that, everybody knows that. But he's good at everything, even now at descending, and the team knows how to control a race in the crosswinds. He's a really good climber, so for us it's a good Tour."