Hurdles star Liu Xiang has been dreaming for years about finding the perfect combination at the Beijing Games - smooth running and explosive jumps. It is a combination he is desperate to find since he bears the expectations of an entire nation as he tries to defend his 110m Olympic gold.

No wonder he is so picky about his shoes.

"It's always a challenge to provide the perfect apparel for elite athletes like Liu Xiang," said Arrel Lu, a designer of Liu's track shoes. "How to support him better at the Beijing Games has been one of our biggest tasks in recent years."

Lu has been working with Liu since 2005, the year after the hurdler won a historic gold medal in Athens.

As the one who conveys ideas between Liu and other Nike designers at the company's headquarters in Beaverton, Oregon, Lu knows exactly what Liu loves and hates.

"The ones he likes most are the original spikes he used to win the gold medal at the 2004 Athens Games," she said. "So the design of that pair of shoes is the basis for Nike's future designs."

Those gold-medal shoes were a pair of Zoom Superfly G5s - white spikes with a red strap and black outsole.

Those shoes were also designed for Liu, who signed with Nike when he was the world junior champion and a world bronze medalist. A special task force designed spikes for Liu, a privilege reserved for megastars like Tiger Woods, Roger Federer and Lance Armstrong.

Liu was expected to be good in Athens, but no one expected him to be good enough to equal the then 13-year-old world record of 12.91 sec and win a gold medal. "Compared with other elite hurdlists in the world, Liu likes a harder outsole because he hits the ground very hard, and a hard outsole gives him good rebound feeling," Lu said.

This idea was improved upon while designing new apparel, and it soon proved to be a success. At the 2006 Super Grand Prix in Lausanne, Liu - wearing Zoom Superfly G5 LXs with a new micro-carbon plate for firmer frontal support - broke the world record at 12.88 sec.

Since then, Liu has stuck with the hard outsole. He wouldn't change it even when Nike tried to persuade him to try a new outsole employing more advanced technology.

"It's understandable because the athlete wanted to keep with the things he felt comfortable and familiar with," Liu said.

For Liu's Beijing shoe, Nike will combine the two designs that led to Liu's two defining moments. They will be a pair of spikes, colored bright yellow with a scarlet outsole. They are called the Zoom Aerofly LX.

The design is nearly the same as both of his previous pairs of shoes, with the addition of the new Flywire technology, which helps reduce weight.

Each shoe weighs only 214 grams, a little heavier than three eggs.