Dutch rider Mathieu Van Der Poel warned his rivals he has hit his peak as he bids for a second win in the 273km Tour of Flanders over the cobbled climbs of the Flemish Ardennes in Belgium on Sunday.

Van der Poel, 27, put his Olympic mountain bike fall and back injury behind him in midweek winning the Round Flanders race.

"I have hit a peak at the right time and I'm going for the win," said the 2020 champion who was beaten to the line in 2021 by Quick Step's Kasper Asgreen.

After a two-year fan ban because of Covid restrictions colossal crowds are expected for what is a major date on the Belgian sports calendar even if Covid has gripped the peloton again with form rider Belgian Wout Van Aert the highest profile victim.

"I spent the last two years going to great efforts not to catch Covid," said the exasperated home hope. "But it was lovely to read all my messages from people concerned about me."

The arduous race over narrow cobbled lanes featuring 18 short but steep climbs starts in Antwerp in what is likely to be close to freezing temperatures and will loop through Flanders towards Oudenaarde where even the toughest athletes will be tested.

Belgian one-day specialists Quick-Step are struggling with Coronavirus cases and even their main remaining hope Denmark's Asgreen, who insists he's on form, had Covid two weeks ago.

"By the end you can be sure the best riders will be ahead and I think I'm part of that group," said Asgreen who was second in 2019 and won in 2021.

Quick-Step star and world champion Julian Alaphilippe has chosen to miss the Flanders races in favour of the Ardennes classics coming later, depriving proceedings of his swashbuckling approach to racing.

But two-time Tour de France champion Tadej Pogacar has emerged as the third man to watch here and has won two of the other ultra-long one day races known as Monuments.

Pogacar would become the first Tour de France holder to win the Tour of Flanders since Eddy Merckx in 1975.

The 23-year-old Team UAE leader Pogacar, who is frequently compared to Merckx, said Van Aert's absence didn't make the task any easier.

"Either way, with or without him, this race will be tense and tight," said Pogacar.

What seems certain is that the 18 sharp ascents means that the lead group will be easily whittled down leaving only the hardiest of athletes in the final chase.

Athletes who can draw from a deep well of endurance such as recent Milan-San Remo winner Matej Mohoric, or the 2019 world champion Mads Pedersen who emerged from a Yorkshire Dales deluge as winner, may however spring a surprise.