More than 5,000 cyclists are expected to tackle the gruelling Etape Caledonia in Highland Perthshire this weekend.
Participants taking part in the Marie Curie Cancer event will face 81 miles of tough rural roads on Sunday, with many of the riders raising funds for the charity partner.
The competition which begins in Pitlochry introduced closed-road cycling to the UK on its debut in 2007 and has since exploded in popularity, with entries for this year’s event selling out in less than three days.
Among the entrants taking part on Sunday will be Commonwealth Games 2015 double silver medallist Louise Haston, who switched from athletics to cycling in 2009.
She has since represented Team GB in the World Cup and World Championships.
Edinburgh-based John Sinclair and his 14-year-old daughter Amy will take part on their 1950s tandem. The pair are aiming to complete the course within five to seven hours.
Meanwhile, Andrew Aitken will be cycling in the event in memory of his father, who was cared for by Marie Curie nurses prior to his death in December last year. He is also running the Edinburgh Marathon and completing two triathlons this month.
He said: “Seeing first-hand how helpful and vital the services Marie Curie nurses provide are, I felt I wanted to give something back to the charity.”
Liz Phillips, a GP from Perth and Kinross, will feature after taking up cycling as a way to keep fit seven years ago. Liz now rides a 30-mile round trip to her surgery each day.
Another rider from Perth and Kinross, Andrew Mitchell, aims to raise £10,000 to support terminally ill people and their families when he takes on a charity pledge place at this year’s event.
According to the event’s organisers, 20% of the cyclists taking part will be women, following the trend of increased female participation in sport across the United Kingdom.