Buchanan has all but locked up the BMX World Cup series before the final race in the United States on Saturday, needing only to make it through to the finals to ensure she finishes at the top of the standings.

Winning the supercross event would ease the pain of crashing out of the world championships earlier this year and kick-start her Olympic Games qualifying campaign.

Despite battling through three major "whiplash crashes and concussions" in the past four months, Buchanan says being cautious and "playing it safe" would be detrimental to her hopes of winning in Chula Vista.

"You never hold back. If I turn up to the track and feel cautious or not committed, I turn around and go home," she said. "If you don't have that full commitment when you're pedalling into a 40-foot jump, there's not much room for error and you'll come off worse.

"There's no holding back in our racing; it's full-tilt dropping onto the track from a three-storey start ramp with big jumps at 50km/h.

"I wear a motocross helmet to protect me ... you shut out the pain. The crashes come with the sport and that's what you put your body through."

Buchanan has won two of the four World Cup events this year in Manchester and Berlin, giving her a 225-point lead over her nearest rival going into the last leg in California.

But the 23-year-old has endured a mixed year of highs, lows and crashes, including a wipeout at the world championships in July.

Buchanan has narrowed her focus this year to BMX, last year attempting to win three world titles in three cycling disciplines. She was successful in two - winning the BMX and mountain bike world championships.

And she is setting her sights on the Rio Olympic Games in 2016 with the qualification process under way.

"You always plan for a perfect season, but it doesn't work out," Buchanan said.

"I want to walk away with this win ... I didn't win it last year because my focus was on the other disciplines.

"This is the last major race with Olympic points up for grabs, so that adds to it as well. I always want to be super-human or 'Superwoman', but I'm hard on myself."

Buchanan is also planning to race at the Olympic test event in Rio next year as she aims to redeem herself for a disappointing finish at the Games two years ago.

The Australian men's charge at glory this weekend will be spearheaded by Anthony Dean, who is second in the World Cup series behind Liam Phillips of Britain.

Fellow South Australian Sam Willoughby will join Dean on the start ramp, with the reigning world champion adding extra spice to an already absorbing race line-up.