Controversy surrounds bike changes during men's time trial world championship

The use of sanctioned bike changes during the elite men's time trial at the UCI Road World Championships is causing heated debate.

Pre-race favourite Tom Dumoulin is among those who have said they will change bikes from a time trial machine to a road bike to tackle to final steep hill in Bergen, Norway, on Wednesday.

The Dutchman says that he will very likely change bikes regardless of his performance as he feels the benefit from swapping to a bike designed for climbing will outweigh the disadvantage of stopping and changing machines prior to the 3.1-kilometre Mount Floyen that rises at over nine per cent gradient.

Dumoulin told Dutch media that he will make a final decision on whether he will change bikes after riding the climb in practice on Tuesday.

"The climb is heavy, but not as heavy as I expected," Dumoulin said. "I understood that it was ten percent on average, but it was not really. There are also sections that go down a bit. That's why it's still a little bit if I'm going to change a bike. Tuesday, after a last good exploration, I'll definitely make a decision."

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Dumoulin has already tasted success at the 2017 championships after his Sunweb team won the men's team time trial on Sunday. He says that the victory will be the 'candle on the cake' after winning the Giro d'Italia in May.

Dumoulin's Dutch team-mate Wilco Kelderman is also looking to change bikes before the climb. "I think you can climb tens of seconds faster on a road bike than on a time trial bike," he said.

The Union Cycliste Internationale (UCI) has said that riders can change bikes during the race, and a bike change area has been set up for the first time in the race's history. There will be a limit for how far helpers can 'push off' a rider after the bike change, with a 20-metre long mat on a cobbled section that must not be exceeded.

Similar bike changes have been employed by teams and riders in other hilly time trials in the past, notably during Grand Tours – for example stage 17 of the 2013 Tour de France, where Chris Froome changed bikes and won the stage, going on to take his first Tour victory.

The Belgian national team posted a video online on Tuesday showing them practicing bike changes in a car park.

Some commentators on social media did not appear happy that riders would be allowed to swap bikes during the race.

The elite men's time trial route takes in 31 kilometres in total, comprising two laps of Bergen and the final climb up Mount Floyen to the finish line.

Dumoulin will face strong competition from the likes of Froome (Great Britain), defending champion Tony Martin (Germany), Jonathan Castroviejo (Spain), Rohan Dennis (Australia), Michal Kwiatkowski (Poland), Edvald Boasson Hagen (Norway) and Victor Campenaerts (Belgium).