I registered a new e-bike in Hangzhou this week and the process was smoother than I expected, but only after I brought the right paper trail. The shop could sell the bike and issue the invoice, but the plate office still wanted to see my passport, residence permit page, local phone number, and the printed purchase invoice with the frame number visible.
The part that slowed me down was the address field. My rental contract uses the compound name in English, while the plate office system needed the Chinese address from the property management stamp. I went back to the compound office, asked them to write the full Chinese address on a small confirmation slip, and the plate office accepted it without any argument.
One practical point: bring the bike itself, not only the paperwork. They checked the frame number directly and photographed the bike before issuing the plate. Has anyone had a different requirement in other districts of Hangzhou?