Innsbruck (AFP) – France's Julian Alaphilippe has been heavily tipped by his rivals to win Sunday's cycling world championships showdown in Innsbruck on what many have described as one of the toughest routes ever.

The race over a draining 258.5 kilometres features almost 5,000 metres of climbing, culminating in a brutal final ascent, a daredevil descent and a slight uphill incline on the last 2km dash for the line where huge crowds are expected in the centre of the Austrian town.

Tour of Spain winner Simon Yates and his twin Adam are also among the favourites and should one of them succeed, it would be the first British winner since Mark Cavendish in 2011.

But the twins both fear the French trident led by Alaphilippe–winner of the King of the Mountains classification in this year's Tour de France–with Romain Bardet and Thibaut Pinot both potential winners too.

"I think Alaphilippe is the main favourite, you have to look at him," Simon said on Friday. "He's in very good form, he's won many good races and he's backed by a very good team, for sure the strongest team. They have many cards to play so it's not just him.” "We all know how good (Alaphilippe) is uphill and downhill," he added.

The twins were in bullish mood at the team hotel on Friday and said they would see how the race panned out before deciding on a final plan of attack. "I'm feeling good, Simon's feeling good and that's all that matters," Adam said. "During the race it's real simple tactics. Anything can happen so we've just got to keep it simple."

Colombian threat

The Colombian national team boasts powerful climbers, led by a tight-knit quartet of Rigoberto Uran, Nairo Quintana, Sergio Henao and Miguel Angel Lopez. "It's a really hard course, super demanding and with that hill coming after six and a half hours riding, I think it'll be very, very hard," said Uran, who came second in the Tour de France in 2017.

Quintana, himself a two-time runner-up in the Tour de France and a winner of both the Giro d'Italia and the Tour of Spain, said his Movistar teammate, Spanish veteran Alejandro Valverde, was also primed to give his best.

"I had him (Valverde) on the phone earlier, he's ready," Quintana told AFP. "But we have four top-level riders and we are representing our country here," he said. "We will try and keep track of the one-day specialists and stop them getting away. Maintaining a fast pace will be very important.”

"But the France team is strong with three riders who can all aspire to the world title.”

Uran also said 2014 champion Michal Kwiatkowski of Team Sky posed a threat, but Quintana tipped the Frenchman: "I think Alaphilippe should win it, but who knows, what I can tell you for sure is this is easily the hardest one-day race I've seen in Europe.”

Alaphilippe himself played down his chances. "There are 50 possible scenarios," he told AFP. "I'm trying to forget the favourite's tag.” "This is a super difficult course and hearing people say I'm the favourite doesn't help me, there are 10 other guys I could name right now with an equal chance," he said.

"But I can promise you my target will be to head home to France on Monday with no regrets."