News Service from House Harris

NSW: Motorbike backflip daredevil to hit the harbour again

SYDNEY, Dec 1 AAP - As he emerged from the waters of Sydney Harbour with a "throbbing headache" and the wind knocked out of him, motorcycle stuntman Cam Sinclair declared he would repeat his world-first jump.

"I'll have another go," a wet and spluttering Sinclair told reporters immediately after Monday's jump.

"Now I need another bike."

Sinclair revved his 250cc dirt bike down the wharf at Pyrmont Point Park five times before launching himself more than 10 metres into the air off a steel ramp and landing in the chilly harbour waters.

His attempted double backflip on the 125kg machine makes him the first person to do the trick over Sydney Harbour.

The tattooed stunt rider, kitted out in full black and red protective riding gear and a lifejacket, said he was not scared and merely "a little bit winded" after the attempt, in which he appeared to rotate one and a half times.

"It went perfect. I jumped off (the bike before it hit the water) a little bit early but I just wanted to prepare myself before I got in the water," the 24-year-old from Melbourne told AAP.

For his next big trick, he will do the same jump but land on a ramp during the Crusty Demons' motorcycle stunt tour Beyond The Apocalypse, scheduled for next year.

A ramp or dirt landing would have been impossible to pull off in the windy conditions that greeted Sinclair in Sydney minutes before the jump.

"Because it's water, you've got plenty of room to land, but if it was dirt you probably wouldn't be able to do it," he said.

"It was a little bit nerve-racking. The ramp was a little bit different."

His training in foam pits came in handy as he rotated in mid-air in front of a crowd of about 50 people and managed to separate from his motorcycle just before entering the water.

With the Sydney Harbour Bridge flags behind him flying at half mast for the late Opera House designer Joern Utzon, Sinclair, who has been riding motorcycles for 19 years, said he wasn't too scared of being hit by the bike.

"No, I wasn't. I don't know what I was thinking, really. I was just trying to jump way out and it worked perfectly," he said surrounded by divers, an ambulance crew, NSW Maritime officials and a support crew.

"I wasn't really scared at all."

The bike, which was hauled out of the harbour by a crane, will be repaired and take pride of place in his home.