KEY POINTS:
BMX might be a mini-drama played out in a matter of 35 seconds but the Olympic women's race has the narrative of a drawn-out soap opera.
The heroine is 20-year-old Sarah Walker, an unpretentious Kawerau girl who mixes girl-next-door with the sort of gritty attitude that sits perfectly
with her sport.
Never has that fortitude been needed more than the past year when her coach, Australian Grant White, responded to a domestic upheaval by walking out on Walker and New Zealand's other BMX hope, Marc Willers, and into the employ of the Great Britain cycling squad.
That rejection would be tough to take in normal circumstances but there is nothing normal about Olympic year and nothing normal about learning your trusted confidante was now coaching your biggest rival for gold - world champion Briton Shanaze Reade.
BikeNZ had to act. Head of high performance Mark Elliott brought in Canadian Ken Cools, known in BMX circles simply as Big Rig.
"It was a difficult one," Elliott said. "In Olympic terms it's a new sport and there's not a lot of depth in coaching. To get access to Ken was fantastic. He's fitted in well to the Kiwi culture and has been a great medium for them both."
But here's where the script gets more convoluted.
Cools' sister, Samantha, is, you guessed it, one of Walker's main rivals for an Olympic medal.
"It doesn't affect me at all," Samantha Cools told Canadian reporters recently. "Me and Sarah are two completely different athletes... I think Sarah is a very lucky girl to be training with my brother. She should take that opportunity and knowledge from him and put it towards her Olympic dream."
There are other sub-plots to throw into the mix.
A BikeNZ source said Willers, ranked fifth in the world, never really hit it off with White, leading to a sometimes strained atmosphere in the small Kiwi BMX team. That has now disappeared.
But most importantly, after a crisis of confidence, Walker says she is starting to ride to her potential again.
"A few months ago I was like 'No, I need more time'," she told the Herald on Sunday.
However a two-week trip to the US recently, riding on a replica Olympic track, soothed the nerves. Walker got it "pretty much dialled in there", which means she knows exactly what the track can throw at her and how she'll deal with it.
"That gave me me a lot of confidence because now I know when I get to the track, I'll have two hours' practice and that will be just reminding myself of what I'm doing."
This script has genuine star quality, too. Walker has turned to New Zealand's greatest cyclist, Sarah Ulmer, in her quest for gold.
"Sarah's been there before, she knows the situations and what it feels like and what to do with nerves. She's the perfect person to help."
Ulmer, for her part, will take little or no credit for any success Walker achieves.
"It's just the the odd email here and there," she said. "I wouldn't claim to be any major part of her support team. She's great, really cool. She's performed bloody well internationally over the past couple of years and is one of many athletes who have potential [to medal]."
While the Athens' gold medallist might be at pains to downplay her role with Walker, her influence goes deeper than she probably realises. Last year, Walker told the Herald on Sunday Ulmer was the reason she decided to make a career of cycling.
Ulmer visited Trident High in Whakatane while Walker was a student - her father teaches there - and she had the good sense to listen as the Olympic pursuit champion and world record-holder talked about motivation.
Walker had intended to chew up dirt for a few years before following Ulmer on to the track - "I would have had a go at track sprinting but, to be honest, going round and round in circles doesn't do much for me" - then BMX became an Olympic sport.
So instead of circles Walker will first negotiate a gate and then a stomach-wrenching two-storey drop into the first corner.
The race is effectively won and lost in those first few gravity-propelled seconds.
If you are not in the first three rounding the first corner, you are likely to be standing watching somewhere other than the podium when the medals are handed out.
To assist her training, a replica of the starter apparatus was erected at Auckland's Millennium Institute and she and her boyfriend, Australian BMXer Dane Booker, spent hours running through her technique.
The key is a conflicting combination of relaxation and vigilance.
Once the riders have taken their place behind the gate they will have between 0.1 and 3 seconds before it drops. Miss the gate by a split second and you miss the medals - simple.
The aim, of course, is to get your front wheel in front on the first corner. That means your elbows are in front and in that frantic first turn, the elbows are as valuable appendages as the legs that power you.
This week, Walker will be behind the gates again in Taiyuan, an hour's flight from Beijing and where the world championships were hosted in May. The Olympic Laoshan course is clay based so will tear up quickly, forcing the riders further afield for training.
If that sounds an inconvenience Walker was not showing it, though her confidence comes with a warning: "Just because you're No 1 [ranked in the world] doesn't mean anything. Everyone who starts in BMX has a chance."
As we have seen, BMX is a small world. There'll be Reade, who will know her every move, and Cools. French duo Anne-Caroline Chausson and Laetitia Le Courguille demand attention.
But Walker, who took up the sport as an 11-year-old after getting bored of watching brother Matt hog the track in Kawerau, knows that if she does something special she'll be given the keys to the town that owes its existence to a timber mill.
She might need them - after the tribulations of the past 12 months she has barely had a chance to see the wood for the trees.
