Mayor of London Boris Johnson spoke optimistically of the involvement of British companies in the Shanghai Pilot Free Trade Zone on Wednesday while posing atop a bicycle on a vertiginous 30th-floor balcony overlooking local landmark the Bund.

Johnson, an avid cyclist known for his signature bicycle-riding commute in 2009 to call for energy conservation, flew into China's financial hub earlier in the day for the second stop of a weeklong jaunt aimed at promoting Sino-British bilateral trade, investment and fold-up British bikes.

One day earlier, the conservative British politician with trademark messy blond hair made headlines by riding the Beijing subway and comparing it favorably to the London underground.

"The free trade zone sounds extremely interesting and exciting. We're looking at which are the excluded sectors ... and trying to work out exactly how far it's going to go," he said.

"But it's a very positive step, very good news, and we look forward to watching future developments, and we hope very much British companies will play their part. And maybe we could manufacture British bicycles in the free trade zone as well."

"It's very important for us to build our friendships, build our relationships with China," he added.

Johnson stepped onto Beijing Subway's Line 1 on Tuesday afternoon to learn about the metro experience in the capital, traveling from Xidan station to Gongzhufen station along Chang'an Street, not long before rush hour, according to The Beijing News.

"Clean", "crowded" and "cheap", were words Johnson used to describe the Beijing subway, after learning that a subway ticket costs only two yuan ($0.33) for the whole journey.

After getting off the subway at Gongzhufen station, he asked staff about the details of the system's design and expressed an interest in learning more.

British media have portrayed his trip as one half of a charm offensive rounded out by Chancellor of the Exchequer George Osborne, who is leading a ministerial delegation around China this week.

Earlier in the week, Osborne outlined plans for relaxed visa rules for Chinese businesspeople and high-spending tourists.

Britain is the second-biggest trading center for the Chinese currency after Singapore.