A stunning ride from American Chloe Dygert helped lift the clouds from a day of brutal weather at the UCI Road World Championships which saw the governing body accused of being "irresponsible" for allowing the men's under-23 time trial to take place.

As torrential rain fell and roads flooded, two riders in the morning's event suffered dramatic crashes directly caused by the conditions.

Denmark's European champion Johan Price-Pejtersen saw his hopes of victory ended when he rode around a bend and into a deep trench of water which sent him flying from his bike, while Hungary's Attila Valter looked like he was riding a water slide when he came off on a descent and went careering down the road.

The women's elite time trial was delayed by 40 minutes as water was siphoned from the road but conditions improved through the afternoon following fears the event may be postponed.

When it did take place, Dygert obliterated the rest of the field, winning by one minute 32.35 seconds from Anna Van Der Breggen – the biggest winning margin for a woman or man since the time trial was added to the world championships in 1994.

Dygert's ride will live long in the memory, but so too will the appalling conditions which struck the under-23 men's race in the morning.

"It is super dangerous and I think it is irresponsible to let it go ahead," Belgian rider Ilan Van Wilder told Het Laatse Nieuws after completing the 28km course from Ripon which saw torrents of water coming across the road and deep puddles forming on blind corners.

"It was no longer raining, but really pouring. You take the longest route to avoid puddles, against all time trial principles."

Price-Pejtersen began the day as one of the favourites as European champion but finished last following his spill.

"I think it was a bit extreme," the Dane said. "In my opinion I think they should have cancelled it for a bit, until at least the pools (of water) had gone and the rain had stopped being so extreme."

Asked for comment, the UCI did not directly respond to Van Wilder's remarks, but pointed to the measures being taken ahead of the women's elite event.

"The UCI and Yorkshire 2019 will continue to monitor closely the events and take any appropriate decisions," a statement said.

The race was won by Price-Pejtersen's compatriot Mikkel Bjerg, who took the title for a third consecutive year, while Britain's Charlie Quarterman finished 14th.

Dygert is a multiple world champion on the track and last year smashed the individual pursuit world record, but has spent comparatively little time racing on the road since winning the junior road race and time trial at the 2015 world championships in Richmond, Virginia.

This year she became the American time trial champion and then showed her strength by winning all four stages of the Colorado Classic, but even so this ride was a surprise.

"It's always special to wear the stripes," said Dygert, who joked she is no stranger to such conditions as a resident of America's Pacific northwest.

"This is everybody's goal and I'm super thankful to everyone who believed in me on my very bad days to get me to this spot."

Britain's national champion Alice Barnes finished 16th while Hayley Simmonds was down in 26th place, missing out on a top-10 finish which would have earned Britain a second place for the Olympic time trial in Tokyo next year.

"I think I can be happy," said the 24-year-old Barnes, who has only recently focused on time trialling.

"I kind of rode to my powers and to my plan. I think for where I am and for how much time I've really put in to time trialling I can be happy."

Simmonds, one of the earlier starters in the race, said she had been happy with her power numbers but was left frustrated by the uncertainty over whether the event would take place at all.

When the final decision to delay the start by 40 minutes was taken, she had just finished her warm-up.

"I had no idea what to do to be brutally honest," she said. "I ended up warming up for one and half times longer than I normally do. Once they delayed it I almost wish they'd postponed it. I wasn't sure what to do or how I was going to perform."