"Bicycles were part of the scenery in China at that time. All workers rode bikes to work. There were no cars in sight at all," said 77-year-old Yang Maoxiu, CEO of Golden Wheel Group, one of China's biggest bike exporters, which is based in Wuqing district, Tianjin.

However, bikes today are more than just a means of transportation.

Liu Xuequan, chairman of the Tianjin Bicycle Industry Association, said: "We have cars, buses, subways and all kinds of different modes of travel, so the bicycle's function has shifted from simply commuting, to leisure, fitness and much more. Therefore, the materials, technologies and the entire manufacturing system are undergoing a transformation."

Many people believe the birth of the shared bike provided the industry with a "second spring". It involves technology - unlocking the bike and being able to trace the kilometers ridden all through an app.

"That's the good side of shared bikes. In some ways, it pushed the technological advance of the industry and led to bikes being safer and more durable," Liu said.

"But they arrived too quickly for small factories to react and get prepared. They didn't differentiate their products or find their position amid the fierce competition," he added.

The bike-sharing industry is restructuring. In Wangqingtuo and many other places in Tianjin, the prospects for not only small factories and manufacturers appear bleak; many bike stores and outlets have closed as there is little need to own a bicycle when shared ones are widely available.

Dong said her e-bike store is now visited by fewer customers, despite cheap prices.

Huang, from the Shanghai Phoenix Bicycle Assembly Factory, said only a few big names such as Mobike and Ofo are left in the market, and the small factories in Wangqingtuo cannot meet their demands.

Yang said: "Operators need progress and so do products. When management, capital and the level of technology cannot keep up with progress, then operators are doomed.

"Enterprises will become more intensive because small ones won't be able to cope with society's needs. Strengths in technology, capital and personnel all need to reach a scale, and if you can't make it, you will be eliminated," Yang said.

Unlike the bleak situation in Wangqingtuo, Yang's assembly lines are busy and he is still taking some Mobike orders.

He started his cycle business in 1987 and is a pioneer in producing some of China's earliest high-end mountain bikes. He also added a range of colored frames, when most were black.

Yang said he still has strong confidence in the industry, but in the future bikes should be high-end, intelligent and beneficial to people's health.

"People still need bikes, whether as a means of transport, a way of exercise or a personal hobby. This is a product that people like and is always in need of development. As humans and society progress, this product also needs to bring into play its social benefits and effects," he said.

"High-end, intelligent bicycles designed to focus on the mechanics of body movements, such as meeting coordinated efforts of muscles and the nervous system to maintain balance and posture, are where the industry is heading now, both at home and abroad." he added.