Decided to skip Shenzen and concentrate on seeing Guangzhou itself...

My flight arrives at 5:40am and departs at 7:10pm, i'm thinking of doing this bicycle tour that I found very interesting:

http://www.cyclecanton.com/

Unfortunately the tour starts only at 1:30pm and finishing at Huacheng Square around 5:30pm which will be cutting it close. My bags will be checked through and I would already have my onward boarding pass but I will have to go through immigration and security again.

IF I leave the tour a bit early around 5pm and catch a cab from Huacheng square (it's a Sunday evening) to the airport do you think I can make my 7:10pm flight??