Alejandro Valverde of the Movistar team rides during Stage 18 of the Tour de France on July 25 in Valloire, France. Photo: VCG

Established stars Peter Sagan and Alejandro Valverde face a potential generational shift on Sunday as the 2019 world cycling championships wrap up with an epic men's elite road race between Leeds to Harrogate.

The 2019 cycling season has been lit up by youthful riders. Egan Bernal won the Tour de France at 21. Tadej Pogacar finished third at the Vuelta at 20. Remco Evenepoel came second here in the time trial at just 19.

At the other end of the age scale is Valverde. The seasoned 39-year-old, is on flying form for the defence of his title despite giving flat-out performances at the Tour de France and the Vuelta, his Movistar team boss Eusebio Unzue told AFP.

"He's ready, he's always ready for the worlds. There is something about the world championships that makes him light up," said Unzue, who has directed Valverde for years at Movistar.

"Spain have brought a strong team, but maybe this course is more open than at Innsbruck," Unzue, a Spaniard who is not involved with the national team, told AFP in Harrogate.

Valverde finally struck gold in 2018 after first finishing third four times and second twice.

"If this race ends with a select group of riders going into the final kilometer, Valverde will be one of them unless something happens to him," the affable Unzue insisted.

Valverde says the race will finish that way.

"There will be a small group of us because of the rain and the slope at the end suits me," Valverde said Friday.

The main challenge over Sunday's 287-kilometer of likely rain-slick roads appears to be the seven technical laps around the tight Harrogate town center, where crashes have occurred all week.

The wetter-than-usual late September in Yorkshire has opened the door for an unexpected winner. 

British ace Chris Froome is absent after a spring fall, while 2018 Tour de France champion the popular Welshman Geraint Thomas is riding despite pulling out of the time trial last week saying he was off form.

"I'll stay in the wheels and try and hold on, obviously it would be amazing but maybe top five is the target," Thomas said Friday.

The road race looks very much like a Belgian spring classic run on rainy, narrow roads over great distances.

The Belgian team is strong. Olympic champion Greg van Avermaet recently won the Quebec grand prix, Philippe Gilbert won the Paris-­Roubaix cobbled classic this season before winning two stages in emphatic style at the Vuelta.

The 19-year-old Evenepoel won the junior road race and time trial at Innsbruck last season. 

If 30 or so riders come home together, that would offer a tantalising chance to three-time former winner the 29-year-old Slovak Sagan.

There could even be an Australian double in the men's marquee races. Rohan Dennis took the time trial and powerful puncher Michael Matthews has said repeatedly this week 'I'm here to win' in the road race. 

The favorite is Dutch 24-year-old Mathieu van der Poel who told the Dutch press this week he dreams of adding the world title here to his European mountain-bike title and world cyclo-cross title. 

Frenchman Julian Alaphilippe, who started as the favorite last year but fell off the pace deep into the race, arrived in Yorkshire on Friday still on a high after his 14 days in the Tour de France yellow jersey.

"This will be the best year of my life with or without a world title," Alaphilippe told AFP.