Thanks guys for the input. I hope this thread could grow, in order for us to know all the hidden gems around Shanghai.

Euphonius, I read your RR when you first posted it, and this is where my inspiration came from for next weekend. But I'll ride the G318 then the 104, I will report the duration of the trip (remember I only have a small 150cc... ;-)) )
Steve, I thought about this too, but it takes the spontaneity off unfortunately. For the trains, you need a minimum of planning (go buy the tickets, then go the the train station, carry all your gear, etc.). The reason I took a bike was to be able to decide in 5mn according to the weather to go outside Shanghai and see a little bit of green scenery. That's why I would prefer that we share nice sceneries/roads/landscapes available by bike for 1-day or WE rides. Thank you anyway for the tip ! ;-))