Defending champion Mathieu van der Poel goes into Sunday's muddy, cobbled Paris-Roubaix bike race sceptical over new safety measures in a week when several of the sport's biggest stars were hospitalised.

Miles of mud and millions of cobbles have lent the race the name of 'the Hell of the North' and a reputation of the most gruelling one-day race in cycling.

In 2018, one competitor the Belgian Michael Goolaerts was found slumped dead by the roadside after heart failure, and the peloton will pass a memorial to him along the route.

First run in 1896, broken wheels and broken bones have been part of the history of the annual race due to the hefty hunks of cobble that surface around 57km of the 260km route.

Organisers this week introduced a u-turn to slow the riders ahead of their entry into the legendary section outside the 650m deep Arenberg coal-mine.

World champion and one day racing's hottest star van der Poel asked on X: "Is this a joke".

But as cycling fans tune in Sunday, their thoughts will be with Tour de France champion Jonas Vingegaard, Remco Evenepoel and Primoz Roglic, who were among those hospitalised after crashing at the Tour of the Basque Country on Thursday.

Of road cycling's five huge one-day races known as the Monuments due to their epic length Paris-Roubaix, which now starts in Compiegne 80km from the French capital, is known as 'Queen of the classics' because it is the toughest.

The 25 teams select seven of their sturdiest riders on the cobbles to cope with the repeated punctures and frequent falls.

Paris-Roubaix Winner Gets Cold Beer And Cobblestone

The 2021 winner Sonny Colbrelli fell to the ground at the finish line unrecognisable in a coating of mud. The following year, after a race ridden in drier conditions, champion Dylan van Baarle rode into the Roubaix velodrome cloaked in ghostly grey dust.

Race folklore has it that the cobbles decide the winner, who receives one of the rough-hewn slabs in guise of a champion's trophy along with a cheque of 30,000 euros (32,500 dollars).

The winner also has his name engraved on a plaque at the Roubaix velodrome's iconic outdoor cold showers.

He will also, as tradition requires be presented with a carton of local delicacies -- french fries and a cold beer.

There are 29 cobbled sections along the 260km route, each of them given a star rating of one to five depending on their bone-rattling potential.

Six are four-star and three of them five-star.

The first of them is the Trouee d'Arenberg, where the safety chicane has been introduced.

These sections can be as narrow as three metres, are by no means flat, and are flanked with a daunting drainage ditch on one side.

At last week's other great cobbled classic, the Tour of Flanders, which Van der Poel won with ease, there were no significant accidents.

"I'm lucky to have a team dedicated 110 percent around me," said the 29-year-old Dutch rider.

Yet in the build up to the race one of cycling's top stars Wout van Aert was left moaning in agony after a high-speed fall sparked a safety debate.

Belgian newspaper Het Nieuwsblad had identified the section where the fall eventually occurred as a risk.

That is not the only concern about the road. Roubaix regional officials plead each year with travelling bike fans and curious onlookers to refrain from taking home souvenir cobbles, considered part of the heritage of one of France's less affluent regions.