Organisers of the Strathpuffer cycle marathon are planning to hold the event in January with a reduced field and a limited number of spectators.
Entries will open at 10pm on Friday for the 24-hour winter mountain bike race in the Ross-shire, which will go ahead on January 16 and 17 if Covid-19 restrictions allow.
The number of competitors will be reduced from 1,000 to 750 to allow more space on the course and at the event site. Around 500-700 spectators normally attend the race, but this will also be significantly reduced.
Organisers say Covid restrictions make the event a “moveable feast” and changes may be required to meet government guidance at the time, including physical distancing and face coverings.
Alasdair Lawton, one of the organisers, said: “We’ve started the process with the aim of having the Strathpuffer in January. We may have to change plans if the situation changes, but we’ve decided to go.
“We will make it work as best we can. We have reduced the number of competitors and we will have marshals on the gate to manage spectator numbers.”
He said it was difficult to know what the response will be to the normally sold-out event.
Mr Lawton added: “There are two opposing forces – this is an early return to major events and we always get a massive entry.
“But people are nervous, and rightly so, and may not wish to come to an event of this size at this stage. So I’ve not idea which of those forces will win.”
The Strathpuffer started in 2005 as a one-off local event, but grew into a national phenomenon with a reputation of being one of the toughest mountain bike events in the world.
It is described as “A brutal mix of ice, wind, hail, rain, mud and snow”, often held in freezing temperatures on gruelling terrain.
The race is held over a near eight-mile circuit through the Torrachilty Forest, on the outskirts of Contin, with around 17 hours of the race taking place in darkness.
Competitors can enter as a solo rider, or as part of a team of two or four.