Chen sleeps on the bank of the Songhua River in Jilin, Northeast China's Jilin province, on June 24, 2004. [Photo/CFP]

Besides tough environment, he also had to deal with difficult human factors. When he planned to leave East Asia through the last stop, Myanmar, the Myanmar government turned his visa application down. He had no choice but to cycle uphill the Tibet plateau and reset a route of Pakistan, Afghanistan, Iran, and Turkey.

Chen experienced war-state Afghanistan, keeping high alert at all times. Due to limited conditions, he slept in snow fields reaching minus 30 degree Celsius for four days.

Jan 22, 2012, is the New Year's Eve in traditional Chinese calendar, an occasion where Chinese family get together to celebrate the Spring Festival. On that day, he ate a salty hardtack with snow water as a New Year dinner in a severe blizzard in Turkey.

Chen talks with a man in China Town in London, July 23, 2012. [Photo/CFP]

"I would ride my tricycle when there is a road, and when there's no road, I would board a ship. The food prices in London are very high. I mainly ate bread and onion. It is good for me to come to China Town, two restaurants run by Hong Kong people, they provided free food for me", said Chen.

Chen spent more than 60,000 yuan ($9,108) for the London trip. He borrowed most of the travelling expenses from his relatives. Others were earned by giving a ride for passengers or fund from his supporters.