Upset: Caroline Buchanan. Credit:Getty Images "I feel numb," she says, the bottom lip quivering and the tears starting again. She gives a thumbs up and walks away. Buchanan had gone into the final in London four years ago as one of the favourites, but she'd tried to be cheeky with her choice of gate and finished out of the medals. She finished first and fourth in her first two semi-final runs here on Friday, but when she crashed in the third and wheeled over the line in eighth, it was going to be tight for her to sneak through to the final eight. In the wash-up, she finished on 13 points with Belgium's Elke VanHoof and Russia's Yaroslava Bondarenko but fifth overall on a countback.

Caroline Buchanan crashes out. Credit:Getty Images The top four went through to the final, which was won by Colombia's Mariana Pajon, who had claimed gold in London. Australia's Lauren Reynolds finished sixth in the same semi as Buchanan. "In London, I had the opportunity to be a medallist and didn't believe in myself," Buchanan said. "In the Olympic final I think I fell apart and didn't bring it. This Olympics has been a different story. I can truly say I did everything possible. Missed a medal: Caroline Buchanan. Credit:Getty Images "I qualified well, I set myself up and I haven't been able to watch the footage yet but I pedalled into the transition at the bottom of the ramp, felt myself buckle and in that split second I [cased] the first jump, my handlebars moved forward and I knew in that moment it was going to be a tough ask to finish the lap.

"Everyone knows this is a brutal sport, there are no white lines, no guarantees and I can hold my head high that I am a champion and I've done all I can." Disappointing end: Caroline Buchanan. Credit:Getty Images Australia has suffered plenty of heartache at these Olympics and there was more to witness at the back of the mixed media zone minutes after Buchanan's final run. She rushed through the scrum of reporters and cameramen and you could see how distressed she was. She ripped off her helmet, revealing her signature peroxide-blonde hairstyle that draws comparisons to pop star Pink, and straight into the arms of her former mountain bike coach, Tim Chad.

Soon after, her parents, Gail and Laurie, arrived and embraced her, kissing her gently on the forehead as she broke down and let it all out. Some of the Australian press were close enough to see the drama unfold. It's confronting to witness the moment when it dawns on an athlete that four years of hard work didn't pay off. "We've known each other for a long time now - when she feels it, we all feel it," Chad said. "She will come back from this. She can reinvent herself. She's an extremely talented girl. She's already talking about what she will be doing next." Buchanan and her family have come back from greater adversity. In 2003, when she was 13, bushfires ripped through the outer suburbs of Canberra and the family home was destroyed. The only things the Buchanans managed to rescue were their lives and BMX bikes and trophies.

Cycling became the family's sanctuary, their way back, and Caroline went on to become a world champion in BMX and mountain biking. She cried, too, after the final in London and vowed on the finish line that she would atone in Rio. It's a bold promise to make in a sport best described as a lottery. The start is all-important, so too the way you race. Competitors can ride dirty, pushing their way through and hoping not to fall themselves, or they can race smart and find a way through the pack. The inside line out of gate one is usually preferred. After the race, Buchanan eluded to "bad sportsmanship" but didn't elaborate. She also admitted the track had unnerved her. That inability to pick up the surface flying out the gate on that final run had caused her to buckle and loosen her handlebars. "From the start of this week I have struggled with the colour of the track," she said. "The green was very hard to see, the bottom of the hill was hard to see. You can't put any blame on it, everything happens so quickly."

Before the women's final, Buchanan and Reynolds climbed into the stands, draped in the Australian flag. "After London I didn't have the opportunity to soak up the atmosphere and I wanted to be up in the stands," she said. "I had a huge standing ovation from all the Colombians and I had Majon's dad crying with me up in the stands. I know I'm a champion and that's all that matters."