From Xiamen to Shanghai mass graveyards of dirty bikes, all twisted frames and busted axles and handlebars, have become an unwanted emblem for hundreds of Chinese start-ups that once thrived on the back of easy money, hard graft and a light regulatory touch.

When the idea took hold in 2015, the bike rental companies’ promise to attract China’s booming middle class pulled in billions of dollars from investors even if they often charged cyclists very little or in some cases nothing to use their services. Some, such as Mobike and Ofo, quickly expanded abroad.

However, both have subsequently slashed their overseas presence. Ofo’s founder, Dai Wei, warned that it was teetering on the brink of  bankruptcy, Wukong and Bluegogo have already folded.