Yet Denmark was prepared to take the gamble at both its national and urban pavilions - the only places where bikes are permitted within the Expo Garden. It originally asked guests for a 100-yuan deposit but soon waived this.

"Some clever Chinese people found a way to unpick the lock and reclaim the deposit, so we decided to stop that," said one Danish member of staff.

"We haven't seen any spills that couldn't be fixed by a band aid," said one of his colleagues.

Accidents notwithstanding, the Denmark pavilion was a huge success in its opening two weeks, and it's airy and partially open-plan design makes it one of the best places to head on a hot and humid Shanghai summer's day as most of the other pavilions are closed structures.

The irony of the Denmark Pavilion is that it is composed of ascending and descending circular slopes, whereas Denmark is a flat country - one reason why cycling is a popular and practical way of getting around there.

"Key people, like branding experts, told us it was a stupid idea, that Chinese hate bikes and are embarrassed by them, that they all want to drive SUVs and Minis," said Winther.

"But as you can see, they love them."

"I like this bike very much, it's very green, very economical," said Qi Luhai, who was riding one-handed while videoing his trip with a camcorder. "I ride 300 kilometers every month."

However, The Little Mermaid is the real star of the show and deservedly so. "The way they've positioned it here in the pool, behind the glass, is much better than the view in Denmark, where it sits on rocks and is quite difficult to see," said a Swedish middle-aged man who gave his name as Arne.

Denmark's Odense Pavilion in Puxi has a similar bike-rental service within its 500-sq-m grounds. Its cycling track is half the length of its opposite number in Pudong.