"On group tours, itineraries are tightly scheduled, so with most places you go to you can only snatch a fleeting glance," Li says. "However, traveling on our own we can tailor-make itineraries to our tastes and timetable and take time to see whatever takes our fancy."

Despite their travels, their command of English is still meager, but that is no obstacle to them, and in 2017 when they went to the United States they used Google Translate to communicate with locals. These days, too, there are so many Chinese tourists on the road, or Chinese studying overseas, that it is often easy enough to seek help from them when they are in a spot of bother or simply want some tourist tips.

Li's craze for travel goes back to an epic trip he made 35 years ago, cycling from Guiyang to Beijing when he was 25 in the summer of 1984-a journey of 3,300 kilometers that took 45 days.

The idea of doing the trip came to him three years earlier when he read of a young man who had traversed the country, cycling from Harbin, Heilongjiang province, to Guangzhou, Guangdong province.