The parting monsoon showers descended on Patna last week. Within minutes of rain, Dharamvir Sharma pulled out the plastic sheet tucked under the top of his cycle rickshaw. He stretched the chimki, as he called the sheet, all the way to a bamboo pole attached to the cycle's handlebar, and fixed it, before heading out in the rain.

Unlike the old fashioned decorative top which covers the heads of passengers, the improvised chimki protects both the rickshaw wala and the passenger from the elements.

No one is sure who came up with the idea, but like any good innovation, it's spread like wildfire. Every second rickshaw in Patna has an extended rain cover.

Sharma, who has been pedalling rickshaws for nearly two decades, said he finds the cover useful even during the summer. And it does not cost much. "I bought the chimki for 60 rupees," he said. "This is the second season I'm using it."Some rickshaw walas haven't even bothered with buying a sheet – they have converted abandoned vinyl posters into covers, and fashioned discarded bamboo into poles. Since most of them belong to the artisan castes, they are adept at putting together things.

Sharma is a lohar (ironsmith) by caste. He owns a small parcel of rocky land in Deoghar district of Jharkhand. Even without the chimki, the rain is welcome, he said. It would help the crop of paddy that he has planted back home.