I personally wouldn't bother going shopping for bike stuff in shanghai but sbelltote's advice is pretty spot on. XDS have stores around the city, giant and a few other stores carry pardus and im not sure where stocks camp and sunspeed but they will be around. Bikesoul carry high end stuff but might have some chinese frames and completes too. Theres another shop called club100 but ive never been in thenshop so im not sure what they stock.
If you have a day to kill then you could go to ridenow cycle club(bike shop and also founders of no.6 wheels) and rent a bike for the day. They organize club rides almost every day of the week so you could ask to join or go for a ride around shanghai yourself.
You can add them on wechat @RideNowKen. Ridenow are the most foreigner friendly of the clubs in shanghai and everyone will speak fluent english. If you go into the shop and introduce yourself im sure they will take care of you. Club100 and bikesoul organize group rides as well so you can ask them too
I mean you could go buy a frameset, but you'd have to transport it somehow.
I would just go Disneyland Shanghai. Disneyland California is overpriced, has terrible food and is a clusterf**k of annoying people.
Ive been to Disneyland Shanghai three times. Its much smaller and i wouldnt say much better than the one in Cali