Karen Hanlen has won her battle with Beijing Olympian Rosara Joseph for New Zealand's sole spot in women's cross-country mountain biking at the London Olympics.

The 32-year-old Whakatane physiotherapist and mother of two only took up the sport two years ago but she progressed quickly to a stage where she ventured overseas last year on the World Cup circuit.

She was locked in a battle for selection with Joseph this year, winning the domestic national series and the Oceania title before grabbing a top-10 finish in this year's opening World Cup race in South Africa.

She had two more solid results in Europe but a crash on a brutal course in France last month thwarted her final World Cup. It also claimed Joseph, who broke her wrist in two places during practice, to effectively end her hopes of selection.

Hanlen will be hoping to match Joseph's showing in Beijing, where she placed ninth.

"New Zealand has a history of producing world class women's cross-country mountain bikers from the likes of Kathy Lynch, Susy Pryde, Robyn Wong, Rosara Joseph and now Karen," BikeNZ high performance director Mark Elliott said.

"To achieve such strong performances with such a short time in the sport, as a working physiotherapist with a young family is outstanding and she has the opportunity now to shine on the biggest stage."

Also included in the Olympic team today are BMX riders Sarah Walker, Marc Willers and Kurt Pickard.

Walker finished fourth in the final when BMX made its Olympic debut in Beijing and went on to win the world title the following year in Adelaide and take out the UCI Supercross World Cup overall honours last year.

The Cambridge-based rider, who competes for the Rotorua club, was frustrated with a chronic back injury last year and just missed a spot in the final at last month's world championships after dislocating her shoulder six weeks earlier. She finished runner-up in the 2011 world championships in Copenhagen.

Willers, also from Cambridge, is now based in California and he credits the move to the ultra-competitive environment as a key to his rise in the sport last year, winning the US National title, the Oceania and North American continental honours and a number of key events including the Supercross World Cup titles at Papendal (NED) and the test event in London.

He won every race at the world championships last year until the final where a mistake while leading on the second to last straight saw him finish third.

He, too, has recovered from injury recently and finished seventh at last month's world championships after crashing in the final while challenging for second place.

Pickard, 21, was the 2010 New Zealand champion but after a serious crash racing in Europe, he took some time out of the sport. He returned to impress with his speed, making the quarterfinals at last year's world championships but missed out qualifying in Birmingham last month after his foot pulled out of the clip.

''Sarah and Marc are world class performers who are capable of beating the best on their day,'' Elliott said.

''Kurt has shown he has the speed to match the best but is learning to be more consistent. He has the potential to make the final in London.''

The New Zealand Olympic team now stands at 93 and is expected to rise to approximately 185 over the next month. Upcoming selections include road cycling, eventing, hockey and football.

- © Fairfax NZ News