Mountain biking royalty, Hans Rey, was among the first to test out the new trails.

Rey is known as a pioneer in mountain bike trials and extreme mountain biking, and was inducted into the Mountain Bike Hall of Fame in 1999.

"We were amongst the first get to sample the brand new Bay of Fire trail, and they did an incredible job," he said.

"It's a million berms and rollers and beautiful views and jumps and incredible nature. It's been a really good experience.

"Mountain bikers live for flow so if a trail is built right for us, it's like a symphony."

He said everyone he'd seen had been having a great time.

"It's not easy to ride the whole ride, because it takes you anywhere from four to six hours depending on how good you are and how often you stop, but it's worth it, every minute of it," he said.

He said the trails compared to some of the top trails he had ridden across the world.

"With Derby and now with St Helens, they have a lot of very cool trails going on," he said.

The trails through the state were also aesthetically beautiful and were built to suit both beginner and experienced riders, he said.

"That's why people come here from all over the world, because it's a unique product where everything comes together. It's definitely worth a visit," he said.

After another day riding at St Helens, Rey is off to New Zealand for some heli-biking.

One of the masterminds behind the trails, World Trail director Glen Jacobs, was excited to see the trails up and running after years of work.

"We came out to the St Helens area and started talking about it quite a few years ago," he said.

"There's a trail called the Blue Tier down to Weldborough and then Derby, and a couple of our crew said, 'wouldn't it be amazing if we could get down to the coastline?'," he said.

"So we investigated and went from there, and now we're blown away. It really is going to put St Helens on the map."

Mr Jacobs said the whole township had embraced mountain biking.

"North-East Tasmania is fast becoming the number one place in Australia ... and I think one of the top five in the world," he said.

"It is the only destination where you come from that high alpine area and finish at the coastline like that.

"There's nothing like it in the world."

Mr Jacobs said with Rey spruiking his experience, the trails would go global.

"This is a living, breathing beautiful tourist town, and it's just going to spike," he said.