INDIAN WELLS, California - Short of spending the entire year living in China, US champion Donny Robinson could not have prepared any better for the debut of BMX as an Olympic sport in August.

US BMX Supercross champion Donny Robinson trains at the US Olympic Training Center in Chula Vista, California March 12, 2008. [Agencies]

The diminutive 24-year-old, along with his national squad team mates, has been training on a track at Chula Vista, California, which is a close replica of the daunting circuit to be used for the Beijing Games.

Both BMX Supercross courses were mapped out by prolific American designer Tom Ritzenthaler and Robinson has the added advantage of having won a test event on the Beijing track seven months ago.

"We have a huge advantage because these Supercross tracks were introduced just two years ago and the only time we would ever get to practise on them was when we went to the international events," Robinson told Reuters.

"Everyone would show up and be like a deer caught in the headlights, wondering who would go first because we didn't know what to expect. You never knew what you were in for until you hit them for the first time.

"Luckily Tom is the one who built every single track and we know his style of building. If something doesn't take our fancy, we tell him and he changes it. Bottom line, it's for the good of every rider out there."

Although the Chula Vista track at the US Olympic Training Center and the Beijing course are not absolute carbon copies, they are close enough.

"Chula Vista is about 430 metres long and Beijing is 438 metres," Ritzenthaler told Reuters. "When I get back to Beijing, I will readjust a few things and make the Olympic course a little bit tighter. But there's not really that much difference between the two to the naked eye."

SIGNIFICANT FACTORS

For Robinson, the most significant factors on both circuits are the eight-metre tall starting ramps, the speed generated by the riders and the length of the jumps.

"These Supercross tracks are made for the elite riders and they're not something you can just jump on and ride," he said. "Even now, it takes all of us a little time to adjust.

"No other starting ramp is as tall as the ones we are going off in Beijing and Chula Vista. You've got a three-and-a-half storey start where you hit speeds of 40 mph (64 kph) and then you're wondering what that first jump is going to be like.

"Going down the hill is the biggest speed we carry and our sustained speed has to be in the high twenties, low thirties. The adrenalin rush that you get going to these Supercross events is unreal. It's like riding a bike for the first time.

"We have 15-foot (4.6-metre) lifts on some of the jumps and you're in the air for three or four seconds," added the rider. "It's going to be jaw-dropping for the spectators. They will get blown away."

BMX, an acronym for bicycle motocross, originated in California in the late 1970s when youngsters on bicycles decided to emulate their motocross idols.

Synonymous with California cool, the sport became an integral part of popular culture with its 'radical' moves and has steadily gained impetus worldwide.

The International BMX Federation was founded in 1981, the first world championships were held the following year and, since 1993, BMX has come under the umbrella of the International Cycling Union (UCI).